I'd like to know what everyone is using for motor oil.
I know the pressure is subjective and has to do with the condition of the motor and other factors but would still like to know.

Brand...................Weight of oil........Lowest oil pressure when racing
-------------------------------------------------------------------------
Royal Purple........XPR 20-50............45

im using Amsoil 15-50 race oil called Dominator- seems to be great and with my manual gauge im seeing about 70psi cold and 50 or so hot or more- at idle.

Ken, another data point is oil temps, and these vary quite a bit, and my pressures along with them. This seems to make for more variability inoil pressure than the oils I've tried, which are

Mobil One 15/50 (Red Top)
Mobi1 One 20/50 V-twin
Mobil One 10/40 4T (another motorcycle oil)
Valvoline VR1 Synthetic 15/50
Miller Oil 10/50

I've seen oil pressure as low as 48lbs with oil temps in the 260 range. This was running in 95 degree heat, on someones bumper.
With more attention to oil cooler ducting, my oil temps are down in the 220 to (rarely) 240 range, and my oil pressures close to 60 lbs in racing conditions.

I run Redline 50wt race oil exclusively and swear by it. I've seen some really high oil temps when the oil cooler was blocked and the water boiled out but still no problems. It is a little expensive which makes oil changes a bit depressing, especially when it's spotless coming out of the engine but it's still cheaper than a rebuild!

Ron, how often do you change your oil for it to come out "spotless"?

Big Dog

thats a good question- how often do you guys change your oil in your spec car? Its quite expensive doing an oil change with the amsoil, and ive been doing about every two weekends....