Originally Posted by FricFrac

Whoa hold on guys - you are wasting your money running 94 octane. I was under the same delusion for a long time. You get more power out of lower octane fuel but we need to run 91 to keep the engine from knocking because of our high compression. 91 is optimum whereas 94 is only needed if your car is pinging or knocking and if your 370Z is knocking on 91 you have either bad fuel or a problem with your car.... unless of course your car is boosted then you're gonna want to run 94 or higher