Which kind of gas should I use on my J30t car?

[boris_hu]

1994 J30t125,1000 mile

I feed the regular gasoline(87) for my car about one month after getting the car from the previous owner. I have driven about 1000 miles now. Today I found that the car needs premium gasoline (91) according to the manual.

Should I stop using 87 immediate? or 87 is also all right to my car?

Will the misuing 87 gasoline misfire my car? (I have several randomly misfire about my car)

Thanks.

[DAEDALUS]

The lower the octane, the more likely it will keep on misfiring. More dangerous is the knocking that you don't feel. The car will retard the timing to avoid knock, but this will reduce your mileage. Longevity aside, take some notes. Check your mileage with the 87 and copare it to the 91.

[elwesso]

if the mileage is the same, or worse with premium... then you have probably bad knock sensors.. When I had bad KS I ran 89 octane, and got a little better mileage...

[driverdriver]

I've only used premium for 9 years on my J, she still runs like new.

[boris_hu]

Thanks a lot. I will use the pretium from now.