Thread: Do you see huge benefits in premium/hi-test/whatever you wanna call it.

With a supercharger, yeah, Id be a little weary too. Though I imagine with good spark table set up in the PCM you might be able to get away with it, but I wouldnt want to chance it.

Don't I tested this theory on being able to use regular 87 and got misfires on 3 cylinders, verifyed by scan. So to be sure, I ran it again after a lil while of running premium so I wouldn't totally damage the engine, and got an ses message, scanned it and yep, misfires on 2 cylinders this time. I suggest not doing it at all. 89 is fine for stock-very mildly modded sc 04+'s I run it everyday and get 21 mpg. Don't really know if it is a difference in 97-03 sc gp's.
-steven-

93!!!! no less

Originally Posted by Edmonchuck

I know for the 2004's they say you can use regular, but I am wary with a charger. Thoughts?

Was it the sales people that told you this? I believe there is a sticker on your gas door and maybe even on the gauge cluster that tells you Premium only. When I bought my car I asked and they told me you can use regular, but the performance would be better with Premium. They are actually right though. Your PCM has two timing tables to work from. If you use 87 octance gas, it will used the reduced timing table. My car was ran for it's first 9K miles on only 87. Once I bought it it has only had 93 and the occasional 91 octane. The actual price difference between 93 and 87 is only 20 cents a gal. So a complete fillup would only run $3 extra.

BP 92 no less. Cause thats all i can get

Unless your PCM is setup for it with the appropriate precautions taken, I wouldn't run anything less than 93 octane.

Originally Posted by rynoman03

BP 92 no less. Cause thats all i can get

where do you get 92 the only thing i can find is 91(not that it will make whole lot of difference

Originally Posted by Zef_66

Unless your PCM is setup for it with the appropriate precautions taken, I wouldn't run anything less than 93 octane.

a stock PCM is already setup for this.

Originally Posted by IndeedSS

a stock PCM is already setup for this.

I understand the concept between good fuel and bad fuel spark tables. But those tables don't always get rid of all the KR.

The best way to go about running a lower octane fuel is to scan, scan, scan...and reduce timing wherever you see KR.

Originally Posted by Zef_66

I understand the concept between good fuel and bad fuel spark tables. But those tables don't always get rid of all the KR.

The best way to go about running a lower octane fuel is to scan, scan, scan...and reduce timing wherever you see KR.

Sure that is the optimal way, no doubt.

GM built in that as a safety measure, because they figured people would run 87 despite the stickers and owners manual. The lady that owned my car lived in an area that was very hilly and crooked (locals familiar with hiway T around Labadie). She put 9K miles on it and never ran anything but 87. The dealership filled it up with 87 when I picked it up from them. I was mad, so they paid for my next fill-up with Premium.
I certainly wouldn't do it myself, but other than the enthuiasts, I bet there are a lot of these cars stock with over 100K miles and have only been fed the cheapest fuel available. Sad but true.

Originally Posted by IndeedSS

Sure that is the optimal way, no doubt.

GM built in that as a safety measure, because they figured people would run 87 despite the stickers and owners manual. The lady that owned my car lived in an area that was very hilly and crooked (locals familiar with hiway T around Labadie). She put 9K miles on it and never ran anything but 87. The dealership filled it up with 87 when I picked it up from them. I was mad, so they paid for my next fill-up with Premium.
I certainly wouldn't do it myself, but other than the enthuiasts, I bet there are a lot of these cars stock with over 100K miles and have only been fed the cheapest fuel available. Sad but true.

Yes, I am sure there are lots of people that do this. But how many of those people beat the piss out of their cars, like we do...or at least I do? I would be the old lady that owned your car never went much over 25% throttle. While you can still get KR there, it isn't as likely as when going full throttle.

And I always stand firm on the position to not recommend anything to anyone I wouldn't do myself. Like I try to tell people to always use spring compressors when changing springs on our cars. Sure you can do it without them. But the safest way is with compressors. There are many things in our world that we can do, but it is not always the best idea to do so. And I think running 87 octane on a stock tune is one of them.

Is 93 okay to run in a stock gtp? I always though it would be a little much for stock, or is there a reason I should step up to it from 89?

Originally Posted by s1795so2

Is 93 okay to run in a stock gtp? I always though it would be a little much for stock, or is there a reason I should step up to it from 89?

93 is the recommended fuel for 97-03 GTPs. This is why the gas tank door says "Premium Fuel Only".

And as I stated above, I recommend to run 93 octane unless your PCM is setup specifically for other fuel.

well 04's dont have the premium fuel only anywhere on it, I have looked for it everywhere, so is it safe or cost effective to run it in the 04's?

Originally Posted by s1795so2

well 04's dont have the premium fuel only anywhere on it, I have looked for it everywhere, so is it safe or cost effective to run it in the 04's?

Really? It's not even the owners manual? I'm with Zef, you should be running 93. And Steven I know you can get 93 octane.

fwiw it may look like I'm saying 87 is ok. I would not recommend it even in a stock GTP. Can you run it and beat the crap out of your car? Yes, with the stock pcm settings and normal size pulley. Should you do this? No.

Now back to your inquiry Steven. I need to check with Rick (TooMch) to see if his is labelled. Did you purchase new?

Originally Posted by s1795so2

well 04's dont have the premium fuel only anywhere on it, I have looked for it everywhere, so is it safe or cost effective to run it in the 04's?

On the cost effective part? I don't think so. Not only will your car get lower mileage because of the lower timing the PCM is commanding, the performance will be less, and if you do end up blowing your engine, the $3 you saved on a fill up is no where near enough to pay for the $1500 engine replacement.

Originally Posted by IndeedSS

Really? It's not even the owners manual? I'm with Zef, you should be running 93. And Steven I know you can get 93 octane.

fwiw it may look like I'm saying 87 is ok. I would not recommend it even in a stock GTP. Can you run it and beat the crap out of your car? Yes, with the stock pcm settings and normal size pulley. Should you do this? No.

Now back to your inquiry Steven. I need to check with Rick (TooMch) to see if his is labelled. Did you purchase new?

The shell station down the road has 93, so I can get it. I didn't buy the car new but there was only 10k miles on it when I bought it, and it was a retired couple that owned it before me. Too good of a deal to pass up. I figured there would at least be the "premium fuel only" label on the gas cap, but there is nothing, it is crazy.

Originally Posted by s1795so2

The shell station down the road has 93, so I can get it. I didn't buy the car new but there was only 10k miles on it when I bought it, and it was a retired couple that owned it before me. Too good of a deal to pass up. I figured there would at least be the "premium fuel only" label on the gas cap, but there is nothing, it is crazy.

With as touchy as the 04's are with the GenV blower efficiency it's hard to even imagine no recommendation for premium. Rick hasn't been on IM so I haven't been able to ask him about his.