different cars react differently. my Jeep likes the intake temp between 100F and 110F, where as my girlfriends Ford Focus runs best 110F to 120F. my Jeep starts knocking around 120F, but her focus doesn't knock until around 140F-145F. i can't say for sure what the MPG gain is on either since i haven't done any testing, but my jeep gets better mileage to and from work tank to tank now (about 2 mpg better, 12 mile commute each way)
__________________
|