[doviatt]

hondo434,

If you look at McTimson fuel log it shows quite stable. That is exactly what you want to start with and then hope your test shows improvement over this baseline. Same thing when you try it on your car (a second independent test is ideal) start a baseline keep it stable and then perform test to show/prove improvement or not. Any results will show up on both test results if performed correctly and it is effective. Cruse control is a good way to stabilize the baseline.

Edit:
Or you can save McTimson's gas and read metroMPG's link with an open mind.