---- you wrote:
>" That's why I insist that I see results from a properly-controlled
> scientific experiment before I use a different oil than one that the
> engine manufacturer recommended. Anecdotal evidence and testimonials
> are meaningless. I've heard a lot of testimonials about various oils:"
> Mark J. Blair, KE6MYK <mblair1@home.net>
Mark
I agree with you completely about using the manufacturer recommended oil. I had a low oil pressure problem with Mobil 1 back when it first came out in a Dodge 318. Instead of rebuilding the engine, I put regular 10w40 in it and it has run for the last 15 years without a problem. I am sure the synthetics are better now, but I also needed proof before I would use them again. So about 5 years ago I tested Valvoline 10w40 synthetic against Pennzoil 10w40 regular in a 1200cc formula vee (Volkswagon) race engine on one of my engine dyno's. The tests were done the same day on the same engine using SAE correction factors. What I found was there was no measureable horsepower difference when the oil was warmed up. What was a real surprise was the synthetic gave three horsepower more when the oil was cold (140F degrees) than the regular. This is a lot on a 56 horsepower motor. All of these tests were at wide open throttle from 3000 to 7200 rpm. Since these motors are aircooled, we have n!
o good way to warm them up before a race, so our first 2 or 3 laps are run on cold oil. I rebuild these engines every year and I have not seen any difference in how the bearings have worn. The synthetic also holds more pressure when hot at idle. In summary I now use synthetic in my race engines and manufacturer recommended regular oil in my street engines. My MB's engine put out 63 horsepower at 4000 rpm using regular oil. I have to have a real good reason before I will use something other than the reccomended oil.
Dave Fillman
45 MB
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This archive was generated by hypermail 2b29 : Sat Sep 02 2000 - 09:32:37 PDT