Quote:
Originally Posted by 97 SL320
I'm pretty sure there is a fed regulation that every modern car made has to " run" on 87 regular. ( computer equiped cars with knock sensors not older non computer cars )
I ran my 97 SL320 M104 straight 6 on mid grade for a while then moved to 91, there was a difference in the sharpness of the engine when the switch was made.
If you drive on level ground at 40 ish MPH regular would probably be just fine.
Also see
Regular or Premium? - Feature - Car and Driver |
Just because something will "run" on a fuel doesn't mean it's appropriate, true?
By analogy, your body can "run" on burgers, fries and shakes, but you're not going to be as healthy ("run as well") or live as long as if you eat a balanced diet.
OP: your engine was DESIGNED for premium fuel. This isn't an issue of the knock sensor compensating, either. Yes, it will run on regular (as noted, read the manual...), but you'll be doing long-term damage to the engine and exhaust components -- and cats cost a lot more than the difference in fuel for a few hundred tanks of gas.
Good luck.