Premium Gas or Regular?

[Gtp8806]

Well when i bought my grand prix the car salesman didnt feel that it was necessary at the time to tell me that the car took premium... So It was to my suprise when i opened the fuel door and saw that Premium Only sticker that pissed me off. Thats the main reason i didnt get a 5.9 liter grand cherokee cuz it took premium and got like 8mpg so anyways i went about a week or so using premium on the gtp and well i gave in and put some midgrade in and then i went down to regular.
I noticed that the performance dropped dramatically but other than that is it bad for the engine even if u dont hear it ping or knock. I havent heard a thing or felt anyhting unusual. Im just kind of disturbed about how slow the car is moving. I can barely spin the wheels if i floor it from the a stop. I hear only a chirp if that.

[Ripn12s]

If your going to beat on it or drive hard then I would stick with the premium. If your just daily driving then run the midgrade

[richtazz]

even though you don't hear it, your car is knocking on the 87 octane, and your computer is retarding timing to compensate, hence the lack of power. I would advise running mid-grade minimum.

[BNaylor]

I agree with Rip and Rich. With regular you are getting excessive knock retard (KR) therefore poor performance. Personally, you can get away with mid-grade. For a safety margin drop down one colder in spark plug heat range if you are going to do it permanently. Good luck!






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.

[mtongen]

I would stick with the mid-grade fuel also. The way the fuels work is that the higher the rating the more resistant to premature firing. I know it may seem messed up, but since higher performance vehicles have higher compression ratios and other enhancements the fuel needs to be able to be resistant to lets say, a small peice of carbon that is still hot. This will keep the fuel from igniting earlier that desired. Well thats my 2 cents worth.

[tobster1911]

What is everyones problem with putting in premium? Lets do some math...

Premium is $0.20 per gallon more than the cheep stuff here in CO. At 5 gallons this is a $1.00 difference. My tank from empty to full is less than 15 gallons. So the difference is less than $3.00. People pay more than this for coffee.

Put it this way....I can pay $30 for the cheep gas or I can pay $33 for premium for a full tank of gas. The only time this will matter is if you have really bad gas mileage or you drive a LOT of miles.

[BNaylor]

Originally Posted by tobster1911

What is everyones problem with putting in premium? Lets do some math...

Premium is $0.20 per gallon more than the cheep stuff here in CO. At 5 gallons this is a $1.00 difference. My tank from empty to full is less than 15 gallons. So the difference is less than $3.00. People pay more than this for coffee.

Put it this way....I can pay $30 for the cheep gas or I can pay $33 for premium for a full tank of gas. The only time this will matter is if you have really bad gas mileage or you drive a LOT of miles.

You have to look at the context of when this message thread was started. Remember Katrina and $3.00/gallon?

With the drop in gas prices there is no reason to be cheap and not use premium if you have a GTP.








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.

[the.dude]

I have a question somewhat related to this thread. If a GTP is ran for a long period of time on regular fuel, can there be permanent damage if you switch to premium? I am pretty sure that the previous owner of my car used the cheap stuff. I've never used anything lower than 92 octane since I bought it three years ago. Everything has seemed fine to me, but I've always wondered about that.

[GTP Dad]

No, actually it may happen if you only run regular and run it hard under boost the detonation and knock retard would be very pronounced and could possibly cause damage. If you switch from 87 to 92 octane the engine would benefit from the higher octane and would perform much better overall.

Originally Posted by the.dude

I have a question somewhat related to this thread. If a GTP is ran for a long period of time on regular fuel, can there be permanent damage if you switch to premium? I am pretty sure that the previous owner of my car used the cheap stuff. I've never used anything lower than 92 octane since I bought it three years ago. Everything has seemed fine to me, but I've always wondered about that.

[regalfriend]

You should use premium....With regular you can screw up your motor.... In my area there is 87,89, and 93 at most gas stations...a friend of mine will use the 93 one week and 89 the next week and keep switching back and forth every week...He runs the tank down to 1/4 then fills up....Im also surprised to hear that your tires dont smoke when you punch it, even on regular. Maybe trac control needs to be turned off.

[tobster1911]

Originally Posted by bnaylor3400

You have to look at the context of when this message thread was started. Remember Katrina and $3.00/gallon?

With the drop in gas prices there is no reason to be cheap and not use premium if you have a GTP.

The point of my post was that it does not matter what the price/gallon is. The difference is what people should look at.

After Katrina when gas was $3/gal regular unleaded and you fill a 15gal tank you spend $45. If you put the premium in that same tank @$3.20/gal you spend $48. The difference is $3.00 always if it is $0.20 range from regular to premium. People are complaining about spending $3 more when they fill up thier tanks. The only time I could see this being a problem is if they drive a LOT of miles. Some people do I guess.

[BNaylor]

Originally Posted by tobster1911

The point of my post was that it does not matter what the price/gallon is. The difference is what people should look at.

After Katrina when gas was $3/gal regular unleaded and you fill a 15gal tank you spend $45. If you put the premium in that same tank @$3.20/gal you spend $48. The difference is $3.00 always if it is $0.20 range from regular to premium. People are complaining about spending $3 more when they fill up thier tanks. The only time I could see this being a problem is if they drive a LOT of miles. Some people do I guess.

Evidently it does to some people. You don't hear me complaining about using premium. BTW - When take my GTP out to the dragstrip I use VP C10 and it's $5.50 per gallon. The bottom line is it is better safe than sorry. If the manufacturer specifies premium then that is what should be used. If the person is looking for economy then they should have gotten an economy car.

[JBent9610]

What if you don't have a GTP, would you still recommend running premium? I have a GT and run regular with no problems, but would there be any benefit to me using premium?

[BNaylor]

Originally Posted by JBent9610

What if you don't have a GTP, would you still recommend running premium? I have a GT and run regular with no problems, but would there be any benefit to me using premium?

Unless it's required, it would be a waste of money. You're doing the right thing by running regular. There would be no benefit running premium.

[Madmunky]

Now that I'm starting to understand this better about all the different pros and cons of premium over regular, I have a couple questions.
I've been running 87 in my 95 GTP with the 3.4L DOHC, according to the manual this is ok, but if I switch to an 89 or higher am I going to notice a difference? Should I consider bumping it up if I start modding the engine, with say a CAI or FWI? And finaly, aside from effecting my wallet slightly can it hurt to to play around with the different octanes?
Thx
Jamie