I'm not an expert Taz but I think maybe you're interpreting this wrong. I think what they mean by "economy" is lower grade/lesser octane/cheaper fuel. To use this grade fuel you have to retard timing to avoid detonation. What I mean is don't expect higher MPG by retarding timing. All you'll get is reduced power which may cause lower MPG. Of course H2's are already set up to run on 87 octane so where can you go?? Only higher/more expensive octane. You may gain a slight bit of power and MPG by advancing the timing but not enough to offset the higher cost of the fuel.
__________________
Jonahs
|