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What is the best type of oil?


Wahey

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Errr Yes.

 

Please don't contaminate this thread with that question!

 

If you'd like to see the chemists view than I can post it but, basically he says he wouldn't touch it with your bargepole!

 

Nuff said?

 

Cheers

Simon

 

sales@opieoils.co.uk

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Simon,

 

The theory has been tested

 

http://64.233.161.104/search?q=cache:_dZiQlMxvxgJ:www.nyeautomotive.com/lubeletters/Vol_32_No_3.pdf+POLAR+ESTER+WEAR+TEST&hl=en

 

However, this may be Mobil hype as they may be changing to use AN Synessetic TM after fleet testing and the add pack used in test is not known.

 

Esters still sound good to me with right blend.

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Apologies if I've posted this before but it seem appropriate to now.

 

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.

 

Oh god, this sounds like I only have synthetics on the shelf, I don't I have minerals and "hydrocracked" oils as well. - Different folks, different strokes!

 

Cheers

Simon

 

 

 

sales@opieoils.co.uk

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Parf7,

 

If you need a OW motor oil Mobil 1 OW40 is better. It's the factory fill on every Porsche that leaves the factory which says something.

But it is a light 40wt oil with a Kinematic Viscosity @ 100C of 14.3 cSt and HT/HS viscosity of 3.6. Silkoline 5W40 viscosities are 14.89 and 4.07 respectively, so it is a somewhat heavier oil.

I run Mobil 0W40 in my tintops and it performs very well, but my Caterham HPC VX doesn't like it. The hydraulic lifters can get a bit noisy when the engine gets very hot. I don't know what the problem is; perhaps oil airation. The problem doesn't occur with Mobil 1 15W50. and it doesn't occur with the 10W30 Red Line that I'm using at present.

Application is every thing when taking about the "best oil".

 

 

Quick7

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Simon the oilman,

 

Simon I was somewhat surprised by your recommended oil change periods to Petrolhead:

Street 6000 miles or annual whichever comes first.

Race 5 Hours.

 

Street is fine if somewhat conservative mileage wise but the Track or Race use must be a misprint!!! 5 hours for a high detergent thermally stable PAO/Ester oil? Really it shouldn't make any difference than the street useage. If it was a nondetergent race oil maybe.

Red Line for example recommend the same oil for an entire racing season no matter how many race miles you do up to 18,000 miles in total per annum. High temps' and a high stress enviroment doesn't concern them. their oil is that stable. What does concern them is frequent short trips which allow contaminents to build-up in the oil depleting the additive package. High temps, are good for the oil as it boils off condensation and fuel contaminents.

 

Regards,

 

Peter

 

Quick7

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nverona,

 

"a BMW 3 running as a new York Taxi" . That a good one i can relate to as one of my tintops is a BMW 328. Must be specializing in transporting midgets; can't see it really.

Anyway, Taxi use is low stress on an engine for a number of reasons including very few cold starts. Your more typical taxi in North America is a Ford Crown Victoria with a 4.6 liter 215HP V-8 that routinely rack up 1,000,000 miles with no engine attention whatsoever, and that is on the cheapest bulk oil they can find. The secret to their long life is frequent oil changes (3,000 miles) in conjunction with the high torque, low rpm characteristics of the engine.

 

Quick7

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If you mean are they "proper" synthetics, the answer's no but at the prices they are sold at, you couldn't by synthetic base stocks.

 

The Castrol Magnatec will be better than Halfords own though.

 

If you're looking for decent "cheapish" oils then drop me an email, you'll be surprised, I don't just sell the "whistles and bells" stuff!

 

Cheers

Simon

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I've always changed oil & filter on my high performance engines every 3000 miles. I'm aware that synthetic oils don't need to be changed that often but I do so to remove any swarf that may be suspended in the oil. On the BDR I get oil as hot as possible, open drain plug overnight to drain, remove dry sump and clean with lint free material, remove and drain oil cooler and thermostat and, finally, drian oil pipes.

 

This may be considered over the top but I think of it as an insurance premium - happy to pay the cost and never claim.

 

Peter M, The car's in a heated garage (in winter) so cold start isn't a real problem but it does struggle on cold cold days. Always started at tickover, or at least not over 1500 rpm till oil has circulated and warmed up a bit (2 minutes at least), then driven under 4000 rpm till oil has got to 50 degrees Cent.

 

Norman Verona, 1989 BDR 220bhp, Mem No 2166, the full story here

 

Edited by - nverona on 14 Oct 2004 13:37:52

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Norman,

 

Carb' engines, particularily in performance oriented cars which are set up on the rich side to maximize power, do contaminate the oil faster fuel injection setups. Nevertheless you can easily put on 6 or 7 thousand miles per year with a high quality PAO and/or Ester synthetic before the additive pac' is depleted.

Norman, you didn't mention how many miles per year you drive your Caterham, but for most of us the mileage is academic due to infrequent useand it is simply a matter of changing the oil annually in the spring.

 

Quick7

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Norman,

 

You are to be commended on your warm-up discipline, with one proviso; 50degC oil temp' is not an engine that is fully up to temp' which is 85C min'. I know this time of year in particular it can be difficult to get the oil temp' up, but if you want to minimize engine wear something closer to 85C before extracting max' power would be preferable.

 

Quick7

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Norman,

 

Sorry for the multiple posts; my internet connection is dodgy.

One final comment, regarding your use of Mobil 1 15W50. Obviously your start-up regimen minimizes the effect of the 15W oil which is fairly viscous; even @ 40C the kinematic viscosity is 125 cSt. Mobil 1 0W40 is 80C, Silkolene 5W40 is 92 and 10W50 is 116.5.

If you engine was modern I'd suggest trying Mobil 1 0W40 or a 5W40 like Silkolene but I suspect you bearing clearances are not that tight (I could be wrong). If you want to stick with Mobil there is nothing wrong with blending grades; you could try a 50/50 mix of 15W50 and 0W40 which would give you a heavy 10W40 and see if you oil pressure when hot is not too adversely affected.

Or if you ever go to Europe pick up some 5W50 Mobil 1. It's cSt @ 40C is much better at 105. It is not as shear stable as their 15W50 but then you're not going for long oil changes anyway.

 

Regards,

 

Peter

 

Quick7

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Sorry, mixing oil to get your own grade, does this not defeat the object of all the millions spent by the oil manufacture?

Why not with the bda engine use a 10/w50 F/synthetic and save messing around and all the warming up stuff whatever the climate.

 

X/FLOW 1700 DD 1990

ROAD USE ONLY..SO FAR

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Simon,

 

Any thoughts on Peter's questions of the 7th?

 

Not too keen on mixing but I would assume OK with M1 to beef up 0W40 if you do not want to change brand.

 

Apparantly M1 is going/gone Esterless using AN instead, is this a backwards step performance wise although not cost wise?

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Peter, lots of questions. I do between 5 & 7 thousand mile per annum bpending on the weather. My oil temp gauge rarely gets to an indicated 80c. I suspect it's reading low, the sender is in the sump plug on a dry sumped engine. The highest it's read was between 80 & 90 on the Brize Norton speed runs. I'm sure it's low as when it gets to an indicated 60 the oil thermostat opens for the oil cooler. I'll have the engine out and sump off over christmas (sump gasket leak) so will inspect innards to see if any marks on bores etc.

 

However, it's not due to the condition of the oil that I change it at 3000 miles, it's to "flush" the engine so to speak.

 

Thanks for the advice I may try 0/40w on the next change to see what pressure is.

 

Norman Verona, 1989 BDR 220bhp, Mem No 2166, the full story here

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Mobil 1 is PAO and as far as I'm aware it's always been. It has no ester as far as I'm aware.

 

There is no doubt (from all the information I've posted) that esters have the edge as long as it's a good slug 20% ish not less then 10% or a dribble to make the ester claim.

 

I will be stocking the "double ester" MOTUL 300V products from November and although fairly expensive I feel that they are good products. Certainly chemically and performance wise on a par with Silkolene, just some different viscosities like 5w-30 and 10w-40 available as well.

 

Now, what was Peters question? Seemed to have missed it.

 

Cheers

Simon

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nverona

 

You will get better oil pressure the thicker the oil you use.

 

Just remember oil pressure is a measure of resistance not flow!

 

I would have thought that if you want better pressure you should be using something like a 10w-50.

 

Cheers

Simon

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Many contain kerosene and paraffins and they're not the best thing for your engine.

 

Modern synthetic oils have such good cleaning properties that it's really a thing of the past to be totally honest.

 

I'm sure many will disagree but that's our view.

 

Cheers

Simon

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