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Discussion Starter · #1 ·
I know it's been done before but, as listed in my oil and tires thread, I've been doing a little re-search on AMSOIL 0W-30 and I'm interested in getting an oil debate going.

I found an article that appears to begin rather independant which involves someone looking through various oils and actually calling up a few companies and talking to engineers. It's a very interesting article.

Here's the link:

http://www.searchforparts.com/important_articles/bmw_m3.html


Here are a couple good quotes from it (I'll try not to take any out of contexts. The individual got rather enthusiastic about his oil after talking with the engineers, and I'm trying not to get too much of that here. ):

"In discussions with Mr. Darren Wallace (Technical Design Engineer and Chemist) of AMSOIL Company, he suggested strongly I use the 0W-30 in the M3 for street and track. His suggestion rather surprised me! I asked him, "track too?" and he said "most definitely." I will only lightly attempt to explain why he made his suggestion to me.

He explained that BMW engines, as are most others, had very tight engine tolerances for their bearings, etc. He said using the AMSOIL 0W-30 would protect these bearings (and the entire engine) better than ANY 30 weight grade oil they have ever tested, including their other 30 weight multi-vis grade oils they offer."

"He explained that using a heavier weight oil is not necessary or desired "unless" the engine is built losely (with wide bearing tolerances) which BMW's engine's are not. Also, he stated that car manufacturer's recommendations for using a heavier "petroleum" based oil such as 15W-40 or 15W-50 was only recommended because of the protection those petroleum weight oils could offer. Using lighter synthetic oils in lieu of heavier petroleum based oils offers "more" engine protection while also offering better wear protection too."


And the other links with comparisons/charts/etc ...

http://www.1st-in-synthetics.com/10W30API.htm

http://www.amsoil.com/performancetests/amsoil_vs_mobil1.htm

http://www.authorized-amsoil-dealer-for-...-the-dynometer/

http://www.performanceoiltechnology.com/Amsoilvs.Mobil1.htm

So far it looks like AMSOIL has come out on top. It was interesting to note that apparently they were the first company to develop an API service grade synthetic. Also because they do not waste much money advertising, or sponsoring expensive professional racing series (they do advertise and sponsor a little bit, just not like Mobil/Castrol/etc), you don't pay for anything but the oil and cost to develop it.

Any more thoughts, comments?

Dubbya~
 

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My understanding was that the more an engine resembles a racing engine, the more 'loosely' it will be built to make it spin more freely and account for bigger temp diffs in operation. Susprises me somewhat that BMW's M engines are apparently built to tight bearing tolerances.
 

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To clear up some confusion about bearing clearances as I work for Glacier Vandervell I will get some info monday from our racing bearing division.

Heres what I know about normal roadcar engines, the trend in recent years has been for graded bearings, these were introduced by the Japanese and the purpose of these bearings is to tighten up the allowance on the clearance betwwen bearing and crank, note that the clearance is not reduced just the allowed variation.

For example with an ungraded bearing when you combine the differences in the top and bottom limits of both the Bearing and the crank you may get to the clearance varying anywhere between 2 to 3 thou with a mean of 2.5 thou (guessing here but just showing a principle). When a graded bearing is used the tolerence on the bearing is unchanged but if the allowed variation is 30 Micron then the bearings are individually measured and graded into 4 bands of 10 microns (an overlap is allowed as at 30 a min the measurement itself is not 100%). The engine assembler then measures the cranks on each journal and fits a bearing to suit. The mean clearance is still 2.5 Thou but the variation will now be reduced to say 2.3 to 2.7 thou.

This technique is used mostly on the rods, mains have either no grades or 2/3 broad ones.

More to follow
 

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The purpose of these graded bearings is to reduce vibration, our engineers actually think that this is debatable but the customer is always right so they get graded beadings if they ask for them. The way to extend the life of the bearings is in the bearing material, it is development of the bearing lining that has extended the life of the crank/bearing interface and has also allowed extended oil change periods and the elimination of running in. The most sophisticated bearing materials are found in the new generation of diesel engines, the pressure on the oil film is so great on these engines the bearing has to cope with much longer periods without the luxury of the oil protecting it, these materials cope with greater forces than those in a formula 1 engine even at 18K rpm.
 

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My two pennies worth.

I'm not really brand conscious, but will get something known on the market.

I prefer synthetic to mineral types, they hold up better.

The oil I put in the car needs to have the proper certification - API, SAE, whatever.

I avoid engine oil additives.

Change your oil often.

Use an oil in keeping with your application.

Try visiting Chris Longhurst's Engine oil bible:

http://www.chris-longhurst.com/carbibles/index.html
 

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VincentD, i am curious as to why you avoid oil additives?

in my case, driving a 92 900turbo with 296k miles on the odometer, i had noticed the intake pipes collecting a film of oil upstream from the turbo. it was not a serious leak, i might need to add 1/4 of a quart in between oil changes (i religiously change my oil every 3500 miles).

i have been running Castrol GTX 20w50 oil in both my engine and transmission (manual gearbox) ever since i picked up the car (about 3 years ago with 257k miles on the clock).

i have recently (3 months or so back?) upgraded a few systems... red series APC, EPROM, fuel injectors, turbo tuned muffler and Accel Koolblue air filter, along with new NGK plugs and Magnecor race wires. while i was installing these new parts i had the intake all taken apart and did a thorough cleaning of all the fittings and insides of the pipes and intercooler.

added 2 quarts of Lucas Heavy Duty Oil Stabilizer to the 20w50 Castrol 8k miles back, i pulled my intake apart last night (specifically the turbo to intercooler pipe), looking for any signs of oil leakage. the pipe was clean from end to end. it would seem that the higher viscosity of the oil stabilizer was enough to seal the worn turbo (this turbo and engine both have 296k miles, never rebuilt).

i will post about how everything turns out after next oil change.
 

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Kommando

I don't think graded bearings are that new - my Dad's 1953 Moris Minor (850cc OHV) had graded bearings (and pistons). I know this as I replaced the crankshaft (after a bearing failure) and the new shaft came with instructions on which bearing grade to use.

Perhaps grading fell out of favour when (the then) new cnc machining methods improved the general tolerances, but is now coming back.
 

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I decided to use mobil 0w - 40 because in uk weather, which can go from -25 to plus 28c , the 0w seems best for cold protect and the 40 for hotrun.

With regard to oil additives, i never really entertained the need for them whilst using the latest synth oils but i have another proposition to share with you and i wonder what peoples thoughts are on this and also if anyone else has used it.

This product gets added directly to the bottom engine via engine oil, and heads via petrol, also waterpump via header tank if reqd.
But it is not an oil additive , it is a metal treatment. I have used it in a couple of engines that did very high miles , a toyota supra which i sold with 245000 miles on it, off course it may have reached that mileage anyway but check out the tech data and see what you think
http://www.team-zx1.co.uk/flash.cfm
 

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The ZX1 (Spectrum???) sounds impressive but Saab engines are pretty long-lived anyway.

If they would *** guarantee *** that by using ZX1, I would never have to change the timing chain, then the extra £15 per oil change might well be worth it.
 

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xassh

I tend to avoid oil additives as I feel they don't have any real added benefit. The synthetic oils are 'engineered' oils. They work better at higher temperatures and don't leave as much residue as a mineral oil would. Get the one most suited for your weather conditions.
Although it is recommended that I change every 10,000 km, I prefer to change at about 5,000 or less because by then the oil is beginning to deteriorate.

I've tried engine oil treatments on my other cars, the only time I felt it was of any benefit was on the old Japanese carburetted model. I didn't really see any difference with my Ford Escort. In fact, not long after each treatment, the oxygen sensor would die. Coincidence? Possibly. But I've been put off by the fact that these sensors cost more than any additional savings I may make if I use a particular treatment.

The treatments I will use are things like a fuel system cleaner (to get rid of moisture) or fuel injector cleaners.
 

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I decided to use mobil 0w - 40 because in uk weather, which can go from -25 to plus 28c , the 0w seems best for cold protect and the 40 for hotrun.[/b]
the temperature ranges i am dealing with, living in southern clifornia generally range from about 50 degrees F in the winter to upwards of 100 degrees F in the summer, much hotter even at times in late July through August while stuck on the freeway in stop and go traffic. i caught the thermometer i keep inside my car reading 118 degrees F at one point last summer (this with windows open, fan on and thermometer had been in the shade, hanging off the lower dash).

the external operating temperatures that an engine deals with will vary greatly depending upon where you live. the external temperatures will also affect your internals, as well as how you drive. i live in a hot climate and i drive like i have a lead foot (sometimes! ) so i am more concerned with the possibility of oil breakdown at higher temperatures than i am of the damage from cold starts.

I tend to avoid oil additives as I feel they don't have any real added benefit. The synthetic oils are 'engineered' oils. They work better at higher temperatures and don't leave as much residue as a mineral oil would.[/b]
and i quote from the side of the Castrol GTX 20w50 case in the garage...

Maximum Protection Against Viscosity and Thermal Breakdown[/b]
and from Castrol USA - products - GTX(click the link for Grades)

Even under everyday driving conditions, temperatures of sensitive lubricated components like pistons and rings can exceed 400 F (even higher for turbos). Such searing temperatures cause thermal breakdown. Oil consumption, which relates to oil volatility, increases with higher operating temperatures.  [/b]
i fully agree that today's oils will provide the protection necessary against viscosity and thermal breakdown, but if you have a slight leak somewhere (such as in my case, turbo, seal on the engine intake side) then possibly an additive will help.

if my own engine was running a bit 'tighter', if the turbo was not exhibiting some signs of wear and leakage, then i expect i would be running a thinner oil and no additive.

it all comes down to what you drive, where you drive, how you drive i suppose
 

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Discussion Starter · #12 ·
xassh the bit about oil breaking down if I'm not mistaken, is referred to as the volatility.

http://www.1st-in-synthetics.com/10W30API.htm (halfway down the page)

"The NOACK Volatility Test determines the evaporation loss of lubricants in high temperature service. The more motor oils vaporize, the thicker and heavier they become, contributing to poor circulation, reduced fuel economy and increased oil consumption, wear and emissions. A maximum of 15 percent evaporation loss is allowable to meet API SL and ILSAC GF-3 specifications."

GTX did not appear to do so well in that particular test. Since these tests are conducted by independant laboratories in order to determine the API and other specifications, and they are heavily regulated, the results should be reasonably unbiased. There's even a test where AMSOIL did not come out #1. (Cold crank viscosity.)

Anyway ... next time we pull the Crossle's engine apart we'll take pictures to show you what a season or two's worth of racing does to an engine with AMSOIL.


Dubbya~
 
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