At 12:28 PM 3/7/99 -0500, you wrote:
>I've got a new Audi 4 cylinder turbo (the turbo is oil cooled) with 4,600
>miles on it. I live in eastern NC (relatively mild year round). I plan
>on running several autocrosses/schools each year. What oil and weight
>would you recomend. I was planning on Mobil 1 15W50, but am now
>considering Redline as well. Redline recommends 10W30 or 10W40 for
>street and occasional track use. They discourage use of their 15W50 or
>20W50 in cars whose oil temps are regularly below 225 F. I have yet to
>see my oil temp guage over 200 F. Also, should I go with a synthetic oil
>filter? TIA.
The general approach to oil is to run the viscosity the engine manufacturer
recommends. The Mfgr REALLY knows what is best. This is especially true
with street driven, modern cars where proper oil flow when cold is very
important. With the turbo, you also want to make sure you don't "bake" the
oil in the turbo. I assume it is water cooled also. In any case, letting
the engine run (depending on what the owner's manual says) after getting
the car hot is a common approach to cooling the turbo oil back down to
normal operating temp. It gives the turbo and oil a chance to cool back down.
With autocrossing, the biggest issue is having good lubrication for the
start of a run when the engine may be relatively cold. Probably much more
of an issue with my Formula Ford than with your car.
Mobil 1 is probably just fine (I run it in my race car and, if I had a
turbo street car, would probably run it in it also). The problem with more
expensive oils, such as Redline, is if you don't change it as often as you
would a more affordable oil, you lose some of the benefits. I would either
run the genuine Audi filter, or the correct Fram. The main thing is clean,
reasonably fresh oil, and a high quality filter, and then follow the
manufacturer's instructions.
Engines and oil are so good these days, that any major brand conventional
or synthetic oil, of the correct viscosity is probably just fine for a
stock engine . . . IMHO.
Are you coming to the Tarheel Autocross School at Rocky Mount, NC on the 20th?
Dick Rasmussen
CM 85
85 Van Diemen RF-85 Formula Ford
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