The Noack Volatility index is key to consumption. This is a good comparison of major oils.

http://www.amsoil.com/performancetests/g1971/

Personally, I use the M1 5W/30 extended performance. It is almost equal to the Amsoil and is available for $26 for 5 qt. jug at WalMart. I dont think you can get a better oil for the price. I run the EP for 10K miles between changes with about 1 1/2 qts. added in that time. I really dont see the benefit of RP in a street car. Seems like its a racing oil that gets dumped after every few races anyway so volatility/consumption is not a concern to them.

 

are you checking oil level on hot/warm or cold engine?
the rule is:
engine oil - cold
transmission - warm/hot

 

Great posts. Thanks for all of the info. Maybe it's time to switch back to M1.

Thanks again.

 

I'm actually not talking about when I check my oil. I mean when I do an oil change, only three quarts of oil come out. I still have the old oil and it is as cold as it's going to get and still only three quarts. It goes to the dealer on monday for this and some other small stuff. They will probably reluctantly do another test and they will probably say nothing is wrong.

 

if you are 2 qts low, it should show on the dip stick. If it's not, you have another problem.