Originally Posted by sky-sol
maybe my car's other owners ran 93 or 89 octane and thats way i get bad freeway mileage? :dunno:
naaa because after a few tanks, your ECU will compensate and make all the necessary adjustments. If you're getting shitty milege after a few tanks of the same octane gas (whichever you think you should get better milege with) then something needs to be adjusted/tuned.