Regular versus premium Fuel

[bbrock]

Does it really matter which grade of fuel I use in my GP GTP? I did quite a little shopping for this car and different sales people at each different dealership gave me contradicting opinions. I have seen other threads on this topic but they don't really answer the question. Could someone tell me one way or the other if the additional expense is worth it?

[jessep28]

http://www.automotiveforums.com/vbul...d.php?t=430908

This thread should answer your questions.

[bbrock]

Thanks, I think that I will stick to the premium.

[jessep28]

Under my understanding, the high octane gasoline doesn't prematurely ignite as easily. Since you are stuffing more air and fuel into the combustion chamber by using the supercharger, premature ignition is more likely to occur.

For the NA GT 3800, it's okay to use 87 octane.

Now a more interesting debate: In my area, the 89 octane is cheaper than the 87 but has a 10% blend of ethanol. Any opinions with the ethanol blends on the engines?

[blazeracer]

I have a 2000 GTP I bought new that now has 92,000 on the clock and I have always used 87 octane. I got 29 mpg on a highway trip from TX to AZ two weeks ago. While in TX, I ran a 14.82.. Gee, that's what it ran about 20,000 miles and 50,000 miles ago also. My personal opinion is that for street cars not runnning 11's, higher octane just is a way for petrolium companies to get more $$$$ out of you. Again, 92,000 miles, burns no oil, no check lights, 29 mpg highway, and 14.82 in the 1/4, all on 87 octane... go figure.

[Ripn12s]

blazeracer, stock GTP??

I know that when I go to the track, especially in TX I need the highest oct possible. Of course Im either running a 2.8 or 3.1 pulley.

Ive been running 89 for the past 2 weeks w/ a 2.8 pulley. Havent scanned the car but I know I see atleast 3 deg of kr on 93 oct. Needless to say I have enough self control that I dont beat on the car when running 89 oct.

So, use whatever gas u want. Just remember that u cant beat on the car as much w/ the lower oct

[blazeracer]

Hey Ripn, not completely stock, but not highly hopped up either. Just a 3.4 inch pulley, CAI, and exhaust from the down pipe to the mufflers, ie; u-bend gone, resonator gone, high flow cat, 3 inch pipe to the split then 2 1/2 from there, into the stock mufflers. Actually sound pretty hot with that exhaust set-up. Mild mods, but I'm in the 14's and happy.. for now. Some of the guys have wicked set-ups and definitely need the better fuel. Maybe 13's is a better statement than 11's. Just my opinion though, I've had no problems as of yet. And like you said, how much you beat on it has a lot to do with it also. I drive mine nice, well.. maybe a couple of red light to red light runs a week.

[BNaylor]

I was coming back from Mexico after checking out some systems we have over there. I noticed a late model GTP at a gas pump in Mexico filling up. The gas over there is Pemex and I have no idea what grades they have. The gas is now cheaper than ours. The moral of this story is evidently a GTP will run on anything.

BTW - I use VP Racing C10 unleaded at the dragstrip.



Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.