What engine oil do you use and why?

[ITA_honda]

Mobil 1 Synthetic..easy as that

[BruceG]

To add more "fuel" to the fire,ar ar....a group of aerospace engineers got together and decided to take a look at all the syn oils and see how they might be improved.Below is a link to the PDF and you can google the product. Interesting info on their product.

http://www.synmaxperformancelubrican..._Oil_15W40.pdf

[CRallo]

interesting read Bruce... Sounds like mostly marketing to me... I'd be intersted to hear an expert opinion. Doesn't hurt to try it though right?

[23racer]

I used to use Redline race 40 wt all the time in either one of my cars and replaced it every race. I had no issues, rock solid cold and warm pressures and when the Cougar got up to 250 oil temps, everything was stable. After a while at $17.00 a quart (the RX7 uses 7 quarts and the Cougar 8) it started to get monster expensive and I looked for less costly alternatives.

I tried Mobil 1 20-50 Street Synthetic (race is not available in Canada) and noticed that as my cars got hot, the idle pressures and max pressures would start to drop over time. I also ended up with more in the catch tanks. I spoke to the Mobil Customer Service guys and they recommended that I look at the Mobil 1 Air V Twin oils as they are designed to handle temps over 220 degrees. It was noticeably better, but still not good enough.

So I did some research on a number of oil researcher sites and ended up with either the Redline Oil Line or a couple of the Motul products as the only ones using the best base stock for their products, I think it was class 5 base stock. Both were still way expensive, so somebody suggested that I try Q Racing oil. I was extremely doubtful as I had some poor experiences with Quaker State in the past. So I tried the oils as the price was right and they worked great. I am using the Q Racing Oil in the 15-50 weight and my pressures are rock solid hot and cold and my max temps are lower in both cars.

I am back to changing oil between events again and I am happy as everything is just as stable as it once was. It seems to work in my BP rotary pulling to 9,000 rpm and my 12.5:1 compression V6 Cougar.