[Mike Croley]

I'm not sure of all the reasons for the sanctioning bodies checking fuel in shoe polish racing, but i can think of a couple more possibilities that don't include performance. First might be keeping costs under control. There are some wildly expensive chemicals you can add that will up the performance. Another possibility is safety. Many of the compounds and chemicals that can be added to race gas are very toxic, not only for the racer through skin contact but for the spectators inhaling the fumes.