Do Octane levels matter >>

[BadGT471]

I have put 87 Octane gas in my 02 GAGT since the day that I got it... I'm now at 21k miles, and I was just wondering, if I put 89 (mid grade) or 93 (Premium), will I notice any power increase? I didn't know how the 3400 would respond to a different type of gas... Anyone, any ideas??

[Dr_Kyle]

No, 87 is the best octane for your engine. Plain and simple.

[mfuller]

You only need higher-octane fuel if your engine is knocking.

[71Z28RS]

Agreed on the detonation (spark knock) necessity. You don't need a higher octane unless that is happening. However, if you increase your octane level, you'll usually experience slightly better mpg. But, that's at the cost of higher gas price. So, it's basically a wash. The only real beneficial time to do is when going on vacation so that you don't have to stop as often to fill up.

That is my experience, but every car has it's own personality.

[1/2dolla]

If you get a slight pinging when accelerating than a higher octane will help with the pinging.

[Greed4Speed]

Seeing how I can run 13.56 @ 108 mph in my SS on 87 octane and got a best of 32 MPG w/ 86 octane, no a grand am does not need more octane.

[MJSilver00]

Im not a mechanic here, but just a question... doesnt a certain amount of detonation occur from time to time no matter what? (maybe due to changes in fuel quality) and if you use higher octane wouldnt that happen less often and therefore prolong the life of your engine?

[1/2dolla]

You are correct. Pontiac recommends a minumum of 87 but a higher grade will not hurt anything.

Personally in the hot months I get slight ping under heavy throttle only when gears change. Using 89 or 92 eliminates the ping.

[RedGrandTour]

87 recommended but I use premium all the time. At 90,000 miles I don't regret it. Now when I'm short on cash I'll use 87 but higher octane won't kill the car. Higher octane is for who ever wants to use it. It does more good than bad.

[iceman]

http://www.grandamgt.com/forum/showt...ghlight=octane too

Originally posted by Greed4Speed
Seeing how I can run 13.56 @ 108 mph in my SS on 87 octane and got a best of 32 MPG w/ 86 octane, no a grand am does not need more octane.

only v8 grand ams

if my parents or i put anything under 91 in the camaro, it sounds like CRAP and runs a somewhat sluggish. it gets expensive too... thank gawd our engines arent that high maintence

-dc

[Blackrider]

Originally posted by balludc
only v8 grand ams

if my parents or i put anything under 91 in the camaro, it sounds like CRAP and runs a somewhat sluggish. it gets expensive too... thank gawd our engines arent that high maintence

-dc

Or grand ams with deacked heads

[Greed4Speed]

Originally posted by balludc
only v8 grand ams

if my parents or i put anything under 91 in the camaro, it sounds like CRAP and runs a somewhat sluggish. it gets expensive too... thank gawd our engines arent that high maintence

-dc

I run 87 in the SS all the time w/out a problem or any noticable loss in power. I know they're supposed to have a 2nd fuel map that the comp switches to when you run lower octane fuel. I'm about to run it again w/ 93 octane just for a test. Even if it is faster, it does fine w/the 87 so I'll probably run that for daily driving and trips.

[VaGT]

Originally posted by BadGT471
I have put 87 Octane gas in my 02 GAGT since the day that I got it... I'm now at 21k miles, and I was just wondering, if I put 89 (mid grade) or 93 (Premium), will I notice any power increase? I didn't know how the 3400 would respond to a different type of gas... Anyone, any ideas??

Yes, equal to the weight of the extra money you spend - less weight in the car makes it faster.


Just use a quality name brand gasoline...

[safemode]

i've noticed loss of power at 93, which is expected because my plugs aren't setup for burning that long and so it has to change my spark tables to not detonate. 89 i've noticed is perfect. At least then you can buy from cheap places and still get decent octane levels instead of maybe getting below octane levels from an el-cheapo station.

Ok, since my last thread was closed (87 to 93 Octane) I will come here. Slim25 says:

This topic has been done to death... As a general rule, higher octane in a car that doesn't need it is a waste of money. Quite often, the "increase" in performance in the placebo effect kicking in... I know I'd be annoyed if I shelled out an extra $6.00 per tank only to have no difference.

. BS I say.

Screw the placebo crap. Seriously, I have noticed a better response with my throttle. Also, my parents get better gas mileage with their bonniville with higer octane. I haven't paid attention to my MPG, but there IS a difference. Maybe your car is just **** and won't notice the difference....I dunno.

I have the 3400 engine with no mods.

[kubiache]

Originally Posted by MJSilver00

Im not a mechanic here, but just a question... doesnt a certain amount of detonation occur from time to time no matter what? (maybe due to changes in fuel quality) and if you use higher octane wouldnt that happen less often and therefore prolong the life of your engine?

Yes, under normal cruising, light load conditions, when you start going up a small incline. Large enough that you're going uphill, but small enough that your car doesn't downshift right away. That's a situation where pretty much all cars will see a bit of knock.

[tenspeed]

An easy was to determine if you actually need a higher octane gasoline would be to run several tanks of regular gas and note mileage and gallons. This will give you a baseline MPG. Then run several tanks of a higher grade and see if your mileage increases. If you see the same MPG with both types of gas, you don't "need" the higher octane.

[Gt00]

Some people have money to burn ..... Premium gas burns slower , so if you don't really need it ( compression / timing mods , etc ) you'll get worse mileage and higher emissions because it won't completely burn . But go ahead and buy it .... $$$

[Blackrider]

High compression sucks But I love the lowend torque!