It comes down to driver application....if your heavy footed, then use the good stuff...if your a putterer then 87 will be fine. Ran 87 until Turbo kit installed and so no real difference in milage...since car was new I wasnt all that heavy footed anyways. wish i could say the same AFTER it was kitted! Yes 87 will kill some power.. but if your used to 140 hP 4 cylinders you'll be fine at 240! Its all a head game, who has the biggest numbers. Whats the point of having big numbers if you putter around town and rarely see the hiway?