Dutch

just so everyone knows (which im sure most do) octane rating is the anti-knock performance of petroleum-based fuels. so when a manufacturer calls for premium fuel that usually means theyre running higher compression and the lower octane fuel will cause knock therefore retarding timing therefore reducing performance. this will also affect fuel mileage although not significantly.

TMaxxTim

I have heard this as well. If I were you and were going to run regular all the time vs premium then I'd make sure I'm not losing the savings in gas milage. Just do 2 test tanks in similar conditions to see if you get about the same mileage.

As for me, I'd rather just pay the extra per fillup for More Power! (Tim Taylor grunt), and knowing that I'm not relying on engine computers to keep the car running right. As was said above, they didn't pull the reccomendation out of thin air, they designed it to be run a certain way.

GKLCPA

Missed your post earlier. Ditto on this. You get a lot for your money with a Max or I30. Since they were the same up to 2003, I wouldn't bother with going with the I30/35 just to pay more for the premium name plate when you can get a Maxima with the same stuff. Now that I'm accustomed to rear wheel drive, I've come to prefer it over the FWD Maxima, but all in all, they're very decent cars.

19psi

youre not going to notice a difference if you switch to regular 87 and dont' floor the car and take it to redline on a regular basis. that's wher ethe car makes the most power and where pre ignition would happen. under pre ignition, the knock sensor would see knock and send a signal to the ecu that there's knock. the ecu would then pull timing and you would notice a power loss.

without going full throttle to redline regularly, you'll never notice the difference, as the load wouldn't be high enough to pre ignition the intake charge.

docdgt@com

In my previous message, I forgot to mention that my mpg remains the same; 19-21 in town, and 23-27 on the highway, depending on wind direction and speed. All in all, not bad, and I can't tell the difference in performance but I'm not a heavy footed guy.

skperformance

iTrader: (6)

Just to let the system get something different to more or less calibrate the sensors i run regular once a winter. I have my tank filled with regular right now . The car is slow and i do mean slow.............. under WOT i feel like i lost 2 cylinders it has hesitation and the tranny shifts like crap trying to compensate for the timing changes.

I also have a 98 with vvt-i so it is a higher compression motor with drive by wire . All of those things combined mean it will not run right. Oh yah it will run but not the way it was supposed to. Older LS's will be ok with lower grades but nothing with a variable timing and high compression together.