Fuel Performance
Drifting
Joined: Jun 2005
Posts: 1,837
Likes: 4
Interesting. I've been using BP / Amoco for a long time, but the local stations that sell it annoyed me enough that I started stopping at a Shell station. The car seems to run a tad better, but of course that's really hard to pin down. But my gas milage is up just a bit, and that's not hard to pin down, with the computer keeping track of it. So maybe there is some difference there. Or maybe its just the phase of the moon. Hard to say, really, but I think I'm sticking with the Shell, at least until I have a reason to switch.
Race Director
Joined: Oct 2004
Posts: 10,089
Likes: 14
Dreamrak/larry. That is one compicated business with your gas. Just don't understand why the powers to be in the states don't sort it out so when you buy your gas you know what you are buying, whether it be 87 all the way through to say 95 ron. Looks like by a lot of postings that you have to go to a certain gas station to hopefully get the stuff you want. Seems like a lottery for quality over there. 
Another very important parameter for a particular fuel is its "sensitivity". That's defined as R - M. In general, the lower the sensitivity, the better all around the fuel will perform. In the US, by law, sensitivity cannot be allowed to exceed 10. In Europe, by contrast, where only RON is reported and regulated, sensitivity often runs as high as 30, leading to unpredictable fuel behavior under different operating conditions. The Germans have developed a DIN standard to address this shortcoming of using only RON ratings, but it hasn't yet gained universal traction in Europe among fuel marketers because high RON has been such a useful advertising tool to sell gas. We had a similar issue here 30 years ago, but the government stepped in and forced the use of only (R+M)/2, which took away the marketing advantage of high RON numbers.
