Hi guys,
Has anyone experimented with regular or mid grade gasoline instead of premium. Just wondering as I use regular in my Acura 3.2 without any problems and it's suppose to use premium. I know that the computer would adjust for lower octane and I would probable lose a little performance but would it hurt the engine.

 

I use only regular in all my stuff, my Vette is a '78 L-48, this motor is 8.5 to 1 compression ratio and would not benefit from higher octane. All I can recommend is that you try a lower grade and keep your ears tuned for the sound of pre-ignition or "ping". Lower octane won't hurt the motor as long as it is not pinging.

 

Your computer does not "adjust" for lower octane. All it can do is retard the timing a couple of degrees when it detects engine detonation through the knock sensor. Just try some regular for 2 or 3 tanks and see if your car likes it by not detonating.[8D]

 

I may be wasting money but it says by fill up entry "Use Premium". Hell, I even
add a $3.00 bottle of STP Octane booster to a full tank every couple of months.

 

I use mid grade in my L98 with no ping problems at all and on a recent road trip I got 23 MPG.

 

I heard that the octane lowers as the gas gets older and since I only fill up about once a month, it's not worth it to use lower octane.

 

I agree with mech259.

I have used 87 Octane in my 1989 L98 with no problem. If I do hear some knocking I just refill with Premium to boost the tank's octane.

I believe this could become more of an issue since I've notice gas stations in my area playing games with pricing. Many offer a "gas sale" or 5 Cent off day but only on Regular. 87 was alway 10 cent lower than 89 which was 10 cent lower than 91 (or 93 if offered). That isn't always true now.

 

Detonation can be caused by several factors, compression ratio, ignition timing, carbon buildup in the cylinders, lean fuel condition, egr not functioning properly, etc. Detonation is actually preignition caused by too high cylinder temps and what it does is the preignition flame meets the ignition spark and thats when you hear the "pinging" noise.