What is the best type of oil?

[wag]

So which oil did Voltaire prefer? Did he have a K series engine?

[Petrolhead]

I recd this from Caterham, Friday and just got permission to publish here:

 

Peter,

 

We recommend our 'Caterham Motorsport Oil' which is a 5W/50 fully synthetic developed exclusively to suit the Caterham application.

 

The apollo tank can be charged through the engine in the normal way (though this may take a couple of 'fills and spin overs' to acheive). The dipstick is marked with the correct oil level - though I do admit that this is hard to see.

 

Regards

 

SIMON LAMBERT

Aftersales Manager

 

Peter,

 

Feel free to post this where you like - however, please note the use of the word 'recommend' - which should not be read as 'is the only suitable product and must be used or else'!

 

Regards

Simon.

 

 

Now with SL No 148

[Peter MarieEa]

I checked out Peter Carmichaels thread that Mobil 1 make a 5w-50 grade but it is only available in the States since I've never heard of it. I called Exxon Mobil in the States and they said they don't just the 15w-50 that they have made for 30 years.

Their latest formulation is a 0w-30 Racing oil.

Perhaps Peter could elaborate.

 

Quick7

[Peter Carmichael]

The product data sheet is on their website

 

Sahf London;

every 1st Wednesday from 19:30 at The Duck just around the corner from Clapham Junction station

[Peter MarieEa]

Thanks Peter

Well I found it, unfortunately it looks like it is only available in Europe. Mobil calls it their Rally Formula. Looks like an excellent product with the same Viscosity Index and Pour Point as Mobil's 0w-40 but with the same 100 C Viscosity of their 15w-50.

I'm sure it costs a whole lot more to formulate than their much lower performing 15w-50. I don't want to sound cynical but that's probabily the reason it hasn't replaced it in North America and the UK.

 

Quick7

[Grim Reaper]

Sorry to bring this old fish back to life again but now that Comma have changed their Syner-Z spec from 0W-40 to 0W-30 I am led to believe that it is no longer suitable for the K series.

Not wishing to destroy my engine I have gone in search of the best oil to use.

I have seen similar threads on other car forums (notably BMW and Subaru) whilst searching for alternatives to Caterhams 'recommended' product and have come across one particular person who seems willing to offer advice on oil specs for particular situations.

I have emailed the aforementioned 'expert' in the oil field (pardon the pun) and am awaiting his reply.

If he gives permission I will post it here.

[edmandsd]

Fully synthetic hasn't got adequate film strength IMO. A good semi synthetic such as 10w60 Valvoline would be my recommendation.

 

Home of HTR700

[Grim Reaper]

There seems to be some misnomer about the labelling of 'synthetic' oils... It would appear that due to a court ruling in the US in the past, 'ordinary' oils that have some percentage of 'man made' additives or altered properties in them, can be labelled as 'synthetic' . Having read this I for one am now doubtful as to whether all marked synthetic are actually so.

Whilst an oil marked as 10W-40 may be Ok for the first couple of months it may break down to a 20 when hot very soon afterwards, and a 20 weight oil is not what I would want in my engine at 7000 rpm.

I'll wait and see what this guy has to say or take a look here for a page in the BMW car club forum where he attempts to give some advice to the unwary motorist...

[Petrolhead]

So why not just use the caterham oil

 

Now with SL No 148

[Grim Reaper]

Why buy a Sony when a Thompson will do the same thing? When a Phillips can do it better and costs less!

It's about consumer choice and whether or not the product fits the use its required for and knowing I'm not being ripped off for the same of a name or an endorsement.

I want the best for my engine and I'm going to try to make sure I get it.

I would be interested to see if the Caterham oil is a 'true' type IV synthetic or not.

And for that matter if the Syner-Z was too.

 

[Petrolhead]

Well I see your point re Sony and Thompson and fully understand about not wanting to damage engine but I thought that the Caterham oil was supposed to be up to the job

 

Now with SL No 148

[Phil]

Every one should listen to Mr Carmichael.

 

Evry on should forget th words, hypergrade, motorsport etc.

 

As Peter says, follow the advice he has given and the example 5w reading and the example /50 reading.

 

A quality base crude oil SJ spec and onwards gaurenteed, will not brake down quickly, a none graded oil will.

 

The aditives package in the oil to stop it burning,varnishing,evaporating etc is made by man, and some suppliers use this to promote the oil saying it is synthetic based when it is not a semi or fully synth oil.

 

In order to achieve good viscosity across the temp range the oil will have to be a semi or full synth. A 10w/40 semi synthetic will perform better over a service interval compared to a 10w/40 mineral.

 

A 15w graded oil is slow moving at normal start up tempretures, this makes it feel thicker to the uneducated person making them think it is better, wrong, it is harder to pump around the engine on start up [even on a day like this] lacking vital lubrication on the top end, this also gives the battery more work to do and more strain on the starter ec.

 

The hole idea of Synthetics is to improve and keep film trengh.

 

 

 

 

X/FLOW 1700 DD 1990

ROAD USE ONLY..SO FAR

[David M]

The Caterham guide states 0W-40 as standard..... which suprised me from many of the comments I had read on here.... I must ask CC what they put in at 500mile service as since filling with 0W-40 I am getting a much lower pressure reading than I used to on lengthy hi paced runs..... although many have suggested its just my potentiometer which is Knacked.....

David

 

GF04RCE is built running and on the road.... every day is a Caterham day!!!! He heee!!... pictures here , I am as excited as an excited thing.....

[Slipper man]

I would just use one of the recommended oils - either the Caterham one, that is good enough that Minister are happy to go along with it or Mobil 1 Motorsport 15W/50, which is what Minister used to recommend. Can't see the point in b****ring around myself, especially when the Caterham oil is quite competetive in price with its UK competitors. If you go to France though, try to get the Mobil 1 5W/50, which is 2/3rds of the price that it is here.

[Phil]

Help me with his one please, when cold and the oil is a slow moving type ie a 15w, surely it will give you a high presure reading and as far as I can see this is not always a good thing. Surely a faster moving oil ie 5w giving faster lubrication to the hole engine is more benifitial over high oil pressure.

 

When hot the oil pressure may not be as high as you expect but is good enough to do the job asked and by putting in a higher number oil ie a /60 grade you may try to get back the pressure but at the exspence of lubrication as he oil is harder to pump around and supply engin parts such as bearings fast enough with the higher revs.

 

So as I see it you need a balance of lubrication and pressure.

 

X/FLOW 1700 DD 1990

ROAD USE ONLY..SO FAR

[oilman]

Hi,

 

My name is Simon Barnard and I'm in the oil business. I've been watching the oil related threads here for some time and they are interesting reading. I felt that you should be aware of the difference between synthetic oils mainly due to the Mobil/Castrol courtcase in the US and the labelling issues that it created. Basically any oil which is not "synthetic" in the true sense of the word I.E. created in a laboratory by chemists and not related to petroleum (Hydrocracked or Mineral Oil) can now be legally labelled as synthetic even though is is "molecularly moified" mineral oil.

 

This has profound quality issues for those seeking "superior" true synthetic oils as many cans on the shelves labelled synthetic are simply poorer cousins of the real thing being PAO, Ester or a blend of the two.

 

If you'd like to learn more then read on as this will explain the differences and they are very different!

 

“HYDROCRACKED” (HC) or MOLECULARLY CONVERTED (MC) BASESTOCKS

 

There are many petroleum oils available on the market that are so pure and refined, they can now be passed off as synthetics.

They are not made from true synthetic basestocks (at least not in the way that synthetics have traditionally been defined), but they have so little in common with traditional petroleum basestocks, it is really somewhat silly to classify them as petroleum oils. Petroleum oil basestocks can be put through a super-extreme refining process called “hydrocracking”. In some cases, as in the case of one particular name-brand "synthetic" oil, these highly refined petroleum basestocks can actually be termed and sold as "synthetic".

It is completely legal for lubricants manufacturers to label these oils as "synthetic".

 

These are extremely high performance petroleum basestocks, but they are not truly synthetic the way that most people understand the term and will not necessarily perform to the same level as a premium synthetic oil like PAO (poly alfa olefins) or Esters.

 

Hydrocracking involves changing the actual structure of many of the oil basestock molecules by breaking and fragmenting different molecular structures into far more stable ones. This results in a basestock which has far better thermal and oxidative stability as well as a better ability to maintain proper viscosity through a wide temperature range - when compared to a typical petroleum basestock.

 

Although contaminants are still present, and these are still petroleum basestocks, contamination is minimal and performance characteristics are high. This process also can turn a wider range of crude oil stock into well-performing petroleum lubricant basestocks.

 

TYPES OF SYNTHETIC BASESTOCKS

 

Synthetic basestocks are not all the same. There are few different chemical types that may be used as synthetic basestock fluids. There are only three that are seen commonly in automotive applications:

 

Polyalphaolefins (PAO's)

These are the most common synthetic basestocks used in the US and in Europe. In fact, many synthetics on the market use PAO basestocks exclusively. PAO's are also called synthesized hydrocarbons and contain absolutely no wax, metals, sulfur or phosphorous. Viscosity indexes for nearly all PAO's are around 150, and they have extremely low pour points (normally below –40 degrees F). Although PAO's are also very thermally stable, there are a couple of drawbacks to using PAO basestocks. One drawback to using PAO's is that they are not as oxidatively stable as other synthetics. But, when properly additized, oxidative stability can be achieved.

 

Diesters

These synthetic basestocks offer many of the same benefits of PAO's but are more varied in structure. Therefore, their performance characteristics vary more than PAO's do. Nevertheless, if chosen carefully, diesters generally provide better pour points than PAO's (about -60 to -80 degrees F) and are a little more oxidatively stable when properly additized. Diesters also have very good inherent solvency characteristics which means that not only do they burn cleanly, they also clean out deposits left behind by other lubricants - even without the aid of detergency additives.

They do have one extra benefit though, they are surface-active (electrostatically attracted to metal surfaces), PAO’s are not “polar”, they are “inert”.

 

Polyolesters

Similar to diesters, but slightly more complex. Greater range of pour points and viscosity indexes than diesters, but some polyolester basestocks will outperform diesters with pour points as low as -90 degrees F and viscosity indexes as high as 160 (without VI additive improvers). They are also “polar”.

 

Other synthetic basestocks exist but are not nearly as widely used as those above - especially in automotive type applications. Most synthetics on the market will use a single PAO basestock combined with an adequate additive package to provide a medium quality synthetic lubricant. However, PAO basestocks are not all the same. Their final lubricating characteristics depend on the chemical reactions used to create them.

 

Premium quality synthetics will blend more than one "species" of PAO and/or will blend these PAO basestocks with a certain amount of diester or polyolester in order to create a basestock which combines all of the relative benefits of these different basestocks.

 

This requires a great deal of experience and expertise. As a result, such basestock blending is rare within the synthetic lubricants industry and only done by very experienced companies. In addition, although such blending creates extremely high quality synthetic oils, they don't come cheap. You get what you pay for! Or do you?

 

Cheers

Simon

 

 

 

sales@opieoils.co.uk

[oilman]

Seems that a short lesson on "viscosity" would be welcomed as well.

 

What is this thing called viscosity?

 

It’s written on every can of oil and it’s the most important visible characteristic of an oil.

The viscosity of an oil tells you how it reacts in certain circumstances and how it performs as a lubricant.

When a oil is subjected to external forces, it resists flow due to internal molecular friction and viscosity is the measure of that internal friction. Viscosity is also commonly referred to as the measurement of the oils resistance to flow.

 

There are two methods of viewing an oils resistance to flow. Firstly there is Kinematic Viscosity which is expressed as units indicating the flow of volume over a period of time and this is measured in centistokes (cSt).

An oils viscosity can also be viewed by measured resistance. This is known as Apparent Viscosity and it is measured in centipoises (cP).

 

However in the real world an oils viscosity is also referred to in such terms as thin, light and low etc. This suggests that the oil flows or circulates more easily. Conversly, terms such as heavy and high etc suggest the fluid has a stronger resistance to flow.

 

The reason for viscosity being so important is because it is directly related to the oils load-carrying ability - The greater an oils viscosity, the greater the loads that it can withstand. (It must be added when new not over a period of time as all oils “shear down” with use)

 

An oil must be capable of separating the moving parts in your engine at the operating temperature. On the basis that an oils viscosity is related to its load carrying ability, you could be fooled into thinking that “thicker” oils are better at lubricating but, you’d be wrong in this assumption. The fact is that in the wrong application a high viscosity oil can be just as damaging as using a low viscosity oil.

 

The use of an oil that’s too “thin” can cause metal-to-metal contact, poor sealing and

increased oil consumption and conversely, an oil that’s too “thick” can cause increased friction, reduced energy efficiency, higher operating temperatures, and poor cold starts in cold temperatures.

 

It is very important that you select the correct oil, not too “light” or too “heavy” and your Owners Handbook is a very good place to start as it lists the temperatures and options.

 

Oils thicken at low temperatures and thin as the temperature increases. The actual rate of change is indicated by their viscosity index (this number normally listed on the oils technical data sheet indicates the degree of change in viscosity of an oil within a temperature range, currently 40-100 degrees centigrade)

 

An oil with a high viscosity index, will normally behave similarly at these two temperatures but an oil with a low viscosity index will behave quite differently. It will become very fluid, thin and pour easily at high temperatures. A higher index is better!

 

Multi-grade oils are designed to perform at high and low temperatures by adding polymers to a base oil (5w,10w, 15w etc) which are heat sensitive and “uncoil” to maintain the higher viscosity sae 30,40,50 etc. This means that the oil can be used “all year round” rather than using different oils for summer and winter.

 

It is important to understand that the selection of the correct oil for your car is not just guesswork, you must consider the temperatures at which you need the oil to operate a 0w, 5w oil is better for cold starts as the oil circulates more easily when it’s cold and is able to flow around the engine more easily and quickly, offering protection at the critical moments following cold engine start-up. These oils are also known to give better fuel economy and engine performance.

 

Finally, all oils “shear” or thin down with use and this means that an oil that started life as a 10w-40 will with use become a 10w-20. The period of time this takes depends on the type and quality of the oil. The most “shear stable” oils are proper Synthetics, either PAO (Poly Alph Olefins) or Esters which have very high thermal stability. They are in general of the more expensive variety but last longer and give the best levels of protection.

 

Cheers

Simon

 

sales@opieoils.co.uk

[Grim Reaper]

Ah...that would be the 'expert' I have written to.

Simon, thanks for the info.

Now I'll preempt the questions by asking...What's the best oil for the K series?

I will admit there are many different types and states of tune amongst us (hydraulic and mechanical tappets), and many different uses to which they are put (road or track use) but having recommended an 0W-40/5W-40 for the road going punter for so long, does the change to recommending a 5W-50 come as a surprise?

Is a 50 grade advisable in a road going car? Are those of us using 15W and 60 grade oils possibly inviting damage or excessive wear? ☹️

Is the 50 grade likely to break down to a lower grade if it's being used at high temperatures?

Will using too high a grade oil put undue strain on the oil pump at high temperatures and revs?

How many of the 'premium brand name' oils are not true synthetic (ie non type IV) oils. (been reading up on this elsewhere )

Is it possible to name and shame them? (suppose not)

Oooh, so many questions.....

[oilman]

Ok, I wish it was so simple but it's not going to be but there are some good facts (Mr Carmichael) in particular and some very confused people here.

 

Let's start with some basics:

 

Viscosity is not the be all and end all of oil, "shear stability" is more important. You see a non true synthetic 5w-50 will degrade in a very short space of time (a couple of thosand miles) which means that it could be a 5w-30 with use. It's the use that sorts them out!

 

Why is this? Well you see "hydrocracked" oils need more additives especially VI improvers to prop them up and these additives tend to break down "shear" with use which means that they are unable to keep the oil thick enough.

 

The most "shear stable" oils are true synthetics, created in laboratories by chemists and have no relation to petroleum (hydrockracked) oils and they are more thermally stable to start with so less additives are required so they don't break down so easily.........Following me?

 

So my advice would be to use a "shear stable" proper synthetic oil either PAO or Ester basestock or PAO/Ester blend which will be tougher and protect better. In this case and only using this type of oil I would recommend a 5w-40 Fully Synthetic.

 

This will give you flow when cold 5w and a very thermally stable sae 40 which will not breakdown after a couple of thousand miles.

 

Is an sae 50 required? Well I could put arguments forward for this but once again a true synthetic would be best and possibly a 10w-50 would suit people doing mad things with their cars as it will give outstanding protection at high temperatures without breaking down although some cold start sacrifices would be made using 10w.

 

Selecting the correct oil is more technical than most people realise and understanding which is best is not simple but hopefully the following will explain some of the reasons why you should try to stay in grade as best possible.

 

Surely the thicker the oil the better!

 

This isn't always true - even when using a petroleum oil. Although it is true that

heavier viscosity oils (which are generally thought of as being thicker) will hold up better under heavy loads and high temperatures, this doesn't necessarily make them a better choice for all applications.

On many newer vehicles only 0w-40, 5w40 or 10w40 engine oils are recommended by the

manufacturer. If you choose to use a higher viscosity oil than what is recommended, at the very least you are likely to reduce performance of the engine. Fuel economy will likely go down and engine performance will drop.

In the winter months it is highly recommended that you not use a heavier grade oil than what is recommended by the manufacturer. In cold start conditions you could very well be causing more engine wear than when using a lighter viscosity oil. In the summer months, going to a heavier grade is less of an issue, but there are still some things to be aware of.

 

Moving one grade up from the recommended viscosity is not likely to cause any problems (say from a 10w40 to a 10w50 oil). The differences in pumping and flow resitance will be slight. Although, efficiency of the engine will decrease, the oil will likely still flow adequately through the engine to maintain proper protection. However, it will not likely protect any better than the lighter weight oil recommended by the manufacturer.

Moving two grades up from the recommended viscosity (say 10w40 to 10w-60) is a little more extreme and could cause long term engine damage if not short term. Although the oil will still probably flow ok through the engine, it is a heavier visocosity oil. As such it will be more difficult to pump the oil through the engine. More friction will be present than with a lighter viscosity oil. More friction will be present than with a lighter viscosity oil. More friction means more heat. In other words, by going to a thicker oil in the summer months, you may actually be causing more heat build-up within the engine. You'll still be providing adequate protection from metal to metal contact in the engine by going with a high viscosity, but the higher viscosity will raise engine temperatures.

In the short run, this is no big deal. However, over the long term, when engine components are run at higher temperatures, they WILL wear out more quickly. As such, if you intend on keeping the vehicle for awhile, keep this in mind if you're considering using a heavier weight oil than the manufacturer recommends.

The best advice is to is to stay away from viscosity grades that are not mentioned in your owner's manual unless you are running an entirely differently set up car in which case seek professional advice.

 

No meaning to plug my company but we supply 5 brands of oil and we understand what constitutes a good one. If you want a good ester/pao "shear stable" oil then look here at Silkolene PRO S.

 

http://www.opieoils.co.uk/lubricants.htm

 

Am I biased, perhaps yes, but for good reasons and a lot of experience!

 

Cheers

Simon

 

 

sales@opieoils.co.uk

[captain chaos]

What oils were recommended for the 2L Vx?

 

I've always used 15-50 Mobil 1 from habit but after reading some of the excellent postings here then maybe i'm not using the best oil for my engine. It is tuned, it does lot's of high temp work which is why the 15-50 appealed. However, a 'good' (as in sheer stable) 5-50 must be better than a good 15-50 if not just from the benefits of cold starting. my engine only really runs in the summer but that must still count as cold starts, if just not quite as cold as say minus 5!

Can this cold start thing be overcome by just taking longer to warm the motor prior to moving off and then I can keep my habit of using 15-50?

[fordy]

I promised myself I wouldn't post on the engine oil topics anymore after the last time which resulted in a very upset Andy Noble in a litigious mood on the phone to me. Just for the record I ended up deleting the posts and agreed to write a joint article in LF with Caterham. I was invited to the Comma/Caterham 'oil day' alluded to elsewhere in this thread only to be suddenly uninvited. No further word on the subject since either so I guess when the 'Caterham/Comma' oil article finally does appear in LF you can be sure it had nothing to do with me, or possibly anyone who would have been in a position to question the technical content or Caterham oil strategy on the clubs behalf.

 

Oh well.

 

For the record I am one of these types who actually specifies oil for cars for several big brand European names. Also one of the small cabal at ACEA who writes the European oil specifications (www.acea.be).

 

Peter has given some very good advice by the way (he's been listening and learning).

 

So heres some general advice about choosing oil for your car.

 

Step 1. READ YOUR OWNER GUIDE. Go on, read the instructions. It will tell you in the OG exactly what oil is specified. Usually will make some brand recomendations too.

 

Consider this. The vehicle manufacturer (OEM's we like to call ourselves) will literally spend millions testing a particular type of oil during an engines development. The oil will have been specified carefully to match the engine design in question. It may even be optimised slightly during the engine development. One thing is for sure, the oil (or oils) the engine was developed on really will be the best choice for the engine. The testing process is lengthy and at times extreme. Essentially trying to guarantee the design for the longest time for even the most severe users. Now its normal for the OEM's own brand products to actually be the self same oil the engine was developed on !!! So this would be a very good place to start.

 

Step 2. Lets say you can't get down to your dealership, or are not happy with the choice or price on offer. This is where you need to look at the mandated specification in the OG. Some OEMs write their own specifications and demand these which may or may not be available in places like Halfords, while some are happy to specify general market specs such as ACEA (Europe) or API (US), ILSAC (US/Japan) and JASO (Japan). These specs are developed in cooperation between the major OEMs and are careully considered. An oil would like to claim one of these specs will have the data to show that it has passed at the right limits all the various engine, bench, chemical and physical tests that make up the spec. Typically this could cost an oil company several million dollars in the development of a new oil.

 

The OEMs are legally obliged to provide an alternative specification of oil, but are also entitled to recommend products of their choice, sometimes own brand, which would actually come from a major oil co. or with a commercial tie up and recommend certain big brand oil co products. But remember, unless you use the mandated specification, you are outside the terms of your warranty......

 

Now lets look at the ACEA specs as these are the most common at the moment in Europe.

 

ACEA A categories are for gasoline engines, B categories for diesel engines and E categories are for heavy duty diesel engines (truck), although we won't consider these here.

 

A1/B1 are very high quality (normally Grp III based) low viscosity fuel economy oils only recommended be a few OEMs

A2/B2 represents 'cooking' grade oils, usually mineral oil derived and Grp I/II based

A3/B3 are very good quality general market oils usually Grp I/II and III/IVbased

B4 was a specific type of generally synthetic diesel oil, there was no A4

A5/B5 is the highest quality level, generally synthetic and normally Group III or IV/V based and was generated according to the demands of the new long drain requirements many of the OEMS offer nowadays.

 

Most oils available in Europe are both gasoline and diesel and will claim combinations of the above.

 

If you see oils claiming CCMC, be aware that this was ACEA's predecessor and those specs became obsolete in the early nineties.

 

The 'synthetic' question is only just really hitting us in Europe. Most of the major OEMs are heading towards specs that demand Group III based engine oils and would not previously have described these as synthetic. Since the happenings in the US (mentioned in an earlier post) then this is likely to change so there will be confusion in the short term. Also consider that the real performance difference between Grp III and Grp IV is not that great, but the cost difference is (hence the OEMs shifting towards Grp III).

 

There are high quality big brand products out there that are true synthetics that may not be any better than a seemingly lesser products that meet the same specifications. If the OEM recommends say, A3/B3, my advice would be to find the cheapest A3/B3 you can find.

 

At the end of the day we all buy into brands and theres nothing wrong with that. Some of us don't though and we demand the right to choose for ourselves appropriate products at a reasonable price. For these people, read your owner guide, understand the spec. being asked for and but something that meets that.

 

You may spot that Caterham themselves do not recommend any specifications, preferring to recommend only their own brand oil (which does not claim any specifications at all on the can). I can only sympathise to those of you who bought a new one and would dearly love to know whats a good alternative to the Caterham Motorsport oil, I know I would. Unfortunately the OEM in me says, Caterham must know best. Mustn't they?

 

Lets consider Caterhams position though. They wanted to respond to the constant barrage of questions on what oil to use for the various powetrains they've used over the years, a consolidated range with the Caterham name on sounds like a good idea. They wanted an oil that can do a good job in a x-flow and an R500 EVO engine, a wide remit. Alas, Caterham is small and it would be very difficult for this to commercially stack up. They've have an oil developed especially for them but the return from the sales of that oil would never be high enough to pay for the costs of testing the oil to any industry recognised specifications. This is the position they are in, all with the best intentions. I've no doubt that they will have done some level of testing of the oil on their own engines (not at the same level as the engine supplier would have though), probably with the buy-in from the engine supplier themselves.

 

I'm not sure why they didn't pick an existing qualified oil and rebrand it though, Thats what most of the OEMs do for their own brand stuff. If it were me and I had no money to do a proper signoff on all the engines in question then I'd recommend something I'd done a nominal amount of testing on myself and stick my name on it, then to fulill my obligations on alternative specs i'd pick the highest available spec, like A5/B5 to cover my behind.

 

 

[oilman]

Fordy, nice post. A fellow anorak - we have our uses!

Sound advice, "check your handbook" first, this is always the starting point. The best oil for your style of driving can only be found by trying different ones to see what works best however knowing the type of oil (synthetic/petroleum) is something that should not be ignored.

 

Captain Chaos.

 

Mobil 1 15w-50 is a true synthetic in fact it's a PAO (Poly Alpha Olefin) basestock which is why it is expensive.

 

With regards to a specific recommendation for your car, if 15w-50 is the specified grade in the handbook and it works well then stick to it, you are using a good one. If 15w-50 is correct and you want to see if you would get any benefit from an ester/pao blend then try Silkolene PRO S 15w-50 and see how you get on.

 

I don't think that 5w-50 is necessarily the best of both worlds but it depends on the type of oil it is.

The problem with wide viscosity oils (5w-50, 10w-60) if they are not "true" synthetics is they require a lot of VI Improvers which makes them more prone to "shearing" with use and therefore not giving adequate protection. I would certainly consider an ester/pao 5w-40 if the handbook lists an xxW-40 and see if you get the benefits of using a 5w.

 

With regards to the benefits of "true" synthetics as opposed to "hydrocracked" or molecularly converted mineral oils these are the main ones.

 

Stable Basestocks

 

Synthetic oils are designed from pure, uniform synthetic basestocks, they contain no contaminants or unstable molecules which are prone to thermal and oxidative break down.

Moreover, because of their uniform molecular structure, synthetic lubricants operate with less internal and external friction than petroleum oils which have the non-uniform molecular structure. The result is better heat control, and less heat means less stress to the lubricant.

 

Higher Percentage of Basestock

 

Synthetic oils contain a higher percentage of lubricant basestock than petroleum oils do.

This is because multi-viscosity oils need a great deal of pour point depressant and viscosity modifying additives in order to be sold as multi-viscosity oils.

Synthetic oils, require very little in the way of pour point depressants and viscosity

modifiers. Therefore, synthetic oils can contain a higher percentage of basestock, which actually does most of the lubricating anyway. More basestock leads to longer motor oil life.

 

Additives Used Up More Slowly

 

Petroleum basestocks are much more prone to oxidation than synthetic oils, oxidation inhibitors are needed in greater supply and are used up very quickly. Synthetic oils do oxidize, but at a much slower rate therefore, oxidation inhibiting additives are used up much more slowly.

Synthetic oils provide for better ring seal than petroleum oils do. This minimizes blow-by and reduces contamination by combustion by-products. As a result, corrosion inhibiting additives have less work to do and will last much longer than within a petroleum oil.

 

Excellent Heat Tolerance

 

Synthetics are simply more tolerant to extreme heat than petroleum oils are. When heat builds up within an engine, petroleum oils quickly begin to burn off. They volatize. In other words, the lighter molecules within petroleum oils turn to gas and what's left are the large petroleum oil molecules that are harder to pump. Synthetics are resistant to this burn-off. They will tolerate much higher engine temperatures.

 

Heat Reduction

 

More often than not, vehicle life is determined by engine life. One of the major factors affecting engine life is component wear and/or failure, which is often the result of high temperature operation. The uniformly smooth molecular structure of synthetic oils gives them a much lower coefficient of friction (they slip more easily over one another causing less friction) than petroleum oils. Less friction, of course, means less heat in the system. And, since heat is a major contributor to engine component wear and failure, synthetic oils significantly reduce these two detrimental effects. In addition, because of their uniform molecular structure, synthetic oils do not cause the "blanket effect" which was mentioned earlier. Since each molecule in a synthetic oil is of uniform size, each is equally likely to touch a component surface at any given time, thus moving a certain amount of heat into the oil stream and away from the component. This makes synthetic oils far superior heat transfer agents than conventional petroleum oils.

 

Greater Film Strength

 

Petroleum motor oils have very low film strength in comparison to synthetics. The film strength of a lubricant refers to it's ability to maintain a film of lubricant between two objects when extreme pressure and heat are applied. Synthetic oils will typically have a film strength of 500% to 1000% higher than petroleum oils of comparable viscosity. In fact, believe it or not, even though heavier weight oils typically have higher film strength than lighter weight oils, a 0w30 or 5w-40 weight synthetic oil will likely have higher film strength than a 15w40 or 20w50 petroleum oil.

Thus, even with a lighter weight oil, you can still maintain proper lubricity and reduce the chance of metal to metal contact when using a synthetic oil. Of course, that means that you can use oils that provide far better fuel efficiency and cold weather protection without sacrificing engine protection under high temperature, high load conditions. Obviously, this is a big plus, because you can greatly reduce both cold temperature start-up wear and high temperature/high load engine wear using the same low viscosity oil.

 

Engine Deposit Reduction

 

Petroleum oils tend to leave sludge, varnish and deposits behind after thermal and oxidative break down. They're better than they used to be, but it still occurs. Deposit build-up leads to a significant reduction in engine performance and engine life as well as increasing the number of costly repairs that are necessary. Since synthetic oils have far superior thermal and oxidative stability than petroleum oils, they leave engines virtually varnish, deposit and sludge-free.

 

Better Cold Temperature Fluidity

 

Synthetic oils and other lubricants do not contain paraffins or other waxes which dramatically thicken petroleum oils during cold weather. As a result, they tend to flow much better during cold temperature starts and begin lubricating an engine almost immediately. This leads to significant engine wear reduction, and, therefore, longer engine life and fewer costly repairs.

 

IMPROVED FUEL MILEAGE AND PERFORMANCE

 

As indicated earlier, synthetic oils, because of their uniform molecular structure, are tremendous friction reducers. Less friction leads to increased fuel economy and improved engine performance.

Any energy released from the combustion process that would normally be lost to friction can now be transferred directly to the wheels, providing movement.

Vehicle acceleration becomes swifter and more powerful while using less fuel in the process.

The uniform molecular structure of synthetic oils has another performance enhancing benefit as well. In a petroleum oil, lighter molecules tend to boil off easily, leaving behind much heavier molecules which are difficult to pump. Certainly, the engine loses more energy pumping these heavy molecules than if it were pumping lighter ones. Since synthetic oils have more uniform molecules, fewer of these molecules tend to boil off. More importantly, when they do, the molecules which are left are of the same size and pumpability is not affected.

 

Hope this is of interest.

 

Cheers

Simon

 

 

sales@opieoils.co.uk

[tom7]

Simon,

I've learned more about oil in the last 10 minutes than in the last 10 years, many thanks for the excellent info.

In my engine at present I have 5W-40 oil labelled as 'synthetic', how can I find out whether it is a true synthetic or not, will it be labelled as such?

 

cheers

tom

[oilman]

Tom,

 

I am afraid not unless you have a tech data sheet, even then it may not say so.

 

If you can tell me what it is, I'll do some digging and compare the tech data which will give an indication of how good it is or isn't. There are not too many good ones about these days as they are expensive to produce and the hydrocracking process generates more profit if labelled as synthetic!

 

I have to say that it's unlikely to be a true synthetic sadly.

 

Cheers

Simon

 

 

sales@opieoils.co.uk

[Grim Reaper]

I have three data sheets from Comma in front of me now (faxed through this morning)

They are for Syner-Z (0W-40! not 0W-30 as it is now), Syner-G (5W-40) and Caterham 5W-50.

The pertinent bits (I think) I have reproduced here...

Syner-Z.. Viscosity@100C 14.54cSt, @40C 82.6cSt,VI 184,TBN 8.0, Sulphated Ash mass 1.1%,Phosphorous ash mass 0.1%

Syner-G.. Viscosity@100C 14.1cSt, @40C 83.3cSt,VI 174,TBN 9.9, Sulphated Ash mass 1.1%,Phosphorous ash mass 0.1%

Caterham.. Viscosity@100C 16.6cSt, @40C 100.0cSt,VI 175,No TBN listed,No Sulphated Ash mass figure,No Phosphorous ash mass figure.

Simon, Can you tell anything about the oils from these figures?