SHOdded, when I first got the 15 SHO I used 87 and the max engine RPM in "D" was 5700. Someone on this form said to use premium so now I use 91(that's all we can get in MN) and now the max RPM in "D" is 6200. Is the engine management system able to recognize what octane I am using and adjust accordingly ?
Auggie
P.S. Engine still running strong on conv. oil
Auggie
P.S. Engine still running strong on conv. oil
