What do you use?

I've always used regular. I see no need for premium in a v8 n/a. Not sure why the dealer recomends it. I have no knock and the car runs find on regular.

I was just wonderin cause I accidently clicked premium while filling up today and didn't notice till she was full. I feel 0 difference in how she runs.

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http://www.cardomain.com/ride/3882088

How do you claim to feel no difference? There are a lot of situations where feeling no difference and the actual difference are very different.
Do you even scan? Is your car running a stock bin file? If you are on a stock timing table, and no detonation is logged in multiple WOT scans, I would say to save money and run low octane.

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'04 GP CompG - 2.6" junk

I would imagine it would be the same reason Prem in the caddys, the compression along with timing to make better performance is usually why the " need " for it.


But as long as it is running good with no knock, then save a few pennies. Bit like my bike calls for regular but lately I have been hearing some knock and running premium stops it. I don't "feel " much difference but being that I have hurt two motors I want to be sure that it is not from kr. And even in the car it is like $3 difference. Pretty cheap insurance if you ask me.

sent from my driod x, via my fingers through tapatalk

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2001 white gt coupe with enough crap to make it run mid 13's with 3 bad pistons
2002 40th GTP sedan mostly stock

I got that bluetooth scanner hooked up to my phone. Tracks everything while i drive. (still learning how to use it tho).

I don't plan on continuing with prem. It's more like $10 difference for a full tank which is too much when my paycheck barely pays the bills lol.

Was really just wondering how many of the other gxps run prem?

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http://www.cardomain.com/ride/3882088

When I had mine it was always ran with premium

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Only a memory
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256HP/341TQ
14.05 @ 100.4 2.24 60'

The motor doesn't have to be supercharged or turbo to need premium fuel. As bigdog said, compression ratio and the amount of timing advance determine if it's needed. As for the price difference between regular and premium it's only a few buck more not $10. 20 cents more x 15 gallons is $3 for a full tank of premium.

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Bright Red 2008 G8 GT

Mods: DRCUSTOMPARTS Center Gauge Bezel
Superchips ECM/TCM Tune- Volant CAI
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I switch between premium and mid every fill up. I've never ran regular.

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K&N CAI/Flips Custom Headlights, Tail Lights, Reverse Light,Brake Light/Front STB/Magnaflow Exhaust

2008 Grand Prix GXP

Premium always for me (especially now that i have a tune), a few guys over at LS1tech scanned their stock tune ecm had a bunch of knock while running 87, went away with prem.

I see no reason at all for doing that. Why do you do that?

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Bright Red 2008 G8 GT

Mods: DRCUSTOMPARTS Center Gauge Bezel
Superchips ECM/TCM Tune- Volant CAI
Solo Axlebacks - HID's
Holden V8 Badges
My Website

$3 more for better MPG which over the course of a full tank offsets the $3 more per tank plus some. Silly not to run Premium IMO and 89 (or similar midgrades) are just pointless.
Butt dyno = ricer math. Take it with a grain of salt. Just because you didn't notice a difference over the course of one tank doens't mean there wasn't one or won't be one if you'd continue to run premium.

As Don said, you don't have to be boosted to run Premium (heck mine requires premium and it's N/A). The LS4 is however a 9.9:1 Compression ratio. The LS4 even states that 91+ is recommend, not required, but it is setup to take advanced of higher octanes than 87.
Straight from the owners manual...
"If your vehicle has the 3800 Supercharged V6 engine (VIN Code 4) or the 5.3L V8 engine (VIN Code C), use premium unleaded gasoline with a posted octane rating of 91 or higher. You may also use regular unleaded gasoline rated at 87 octane or higher, but your vehicle's acceleration may be slightly reduced, and you may notice a slight audible knocking noise, commonly referred to as spark knock. If the octane is less than 87, you may notice a heavy knocking noise when you drive."

Also, don't forget that winter blend gas is at the pumps now so at least a winter blend 92-93 will be better than a winter blend of 87. Darn you Ohio and your season of winter!!!!!!!!!

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Dubs:00 VW GTI VR6, Low and Slow 91 VW GTI 8v, Shave the Bay!! 91 VW Cabriolet 8v, bitch Basket
GP's:04 GP GT, Past now G-Ma's Girlfriend's 97 GP GT, "Project Pink Power"

I thought the better octane makes better milage was busted?

Also whats this winter mix thing? I should buy unleaded because it's technically premium? So their charging .20 more for the same gas?

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http://www.cardomain.com/ride/3882088

I thought they switch a year or so ago and pretty much ran the winter mix year round since there is so much crap in the gas...I run premium in my gtp just to be safe and mid grade in the olds...

Your car is designed to run on premium (again someone didn't read their owners manual haha), thus is you run lower octane, you'll get lower MPG. 87 octane technically has more energy density than 93, but when the tuning is set up to run higher timing advance and relatively high compression ratios, the lower energy density is overridden by the detonation resistance of 93. Thus if the engine can run a higher timing advance and not have to pull timing due to Knock, you'll net higher MPG.
For engines actually designed for 87 octane, running 93 might not net higher MPG, but most modern EFI cars will adjusting timing slightly to take advantage of the higher octane. Older engines that don't have sophisticated computers and no way to adjust timing on the fly (distributor ignitions) are even less likely to get any improvements out of a higher octane, especially since as I mentioned, 87 actually has higher energy density.

For one winter blend gas contains more butane which is cheaper, less energy dense, and more volatile. Winter blend is also refined less and contains more hydocarbons but due to the decrease in outside temperature, those chemicals are less likely to evaporate off (volatility) thus winter blend has a high Reid Vapor Pressure (or more volatile mixture) while summer blend, which has less hydrocarbons and less likely to evaporate off, has a low Reid Vapor Pressure. This does however help cold starts, also thanks to the butane, but hurts overall performance and MPG's.
From what I've read, the EPA says that summer blend is about ~2% more energy dense than winter blend.

No they aren't charging more for the same gas, winter blend effects all grades of gasoline, but I've read multiple places that the refiners put less butane in premium grades, as compared to regular, since it's not the "mainstream" gas grade and thus isn't really going to save them all that much money. However, for something as popular as 87, they'll make it as cheaply and with as much butane as they possibly can since it's what sells.

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Dubs:00 VW GTI VR6, Low and Slow 91 VW GTI 8v, Shave the Bay!! 91 VW Cabriolet 8v, bitch Basket
GP's:04 GP GT, Past now G-Ma's Girlfriend's 97 GP GT, "Project Pink Power"

since when do you believe anything the EPA says, Matt =P

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Gt2256v, FMIC, Port & Polish Head, Stage 2 Colt Cam. Rosten Rods, PD150 Pistons, Oil Cooler, Fuel Cooler, Diablo W/M kit, Built 5 speed with LSD
I work on enough GP's to know I don't want to own one =P

I don't, therefore that ~2% is probably more like 5-10% which would add up with people's normal observed drop in MPGs.

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Dubs:00 VW GTI VR6, Low and Slow 91 VW GTI 8v, Shave the Bay!! 91 VW Cabriolet 8v, bitch Basket
GP's:04 GP GT, Past now G-Ma's Girlfriend's 97 GP GT, "Project Pink Power"

I know a fellow who runs 87 in his, but adds 1oz of acetone to every fillup. I tried it a couple times, and I didn't notice anything besides less spark-knock. I had my car pretty well built for N/A, nearly 10:1 compression, +20* timing adv, cams, the whole 9 yards.

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Jay - 99 GP GT, MOST options, no HUD or leather... Meh...

Xbox - b00nd0ck xs41nt

I makes musics... http://soundcloud.com/dj-jack-ripper

You should add ATF to your oil. It's the bees knees for valve seals I hear (;


Disclaimer: Don't do that, unless you don't like your cam and lifters....

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Gt2256v, FMIC, Port & Polish Head, Stage 2 Colt Cam. Rosten Rods, PD150 Pistons, Oil Cooler, Fuel Cooler, Diablo W/M kit, Built 5 speed with LSD
I work on enough GP's to know I don't want to own one =P

http://www.pureenergysystems.com/news/2 ... 9_Acetone/ < My source

ATF 'oil' http://crx.honda-perf.org/faq/data/5.html, Most of it sounds plausible.

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Jay - 99 GP GT, MOST options, no HUD or leather... Meh...

Xbox - b00nd0ck xs41nt

I makes musics... http://soundcloud.com/dj-jack-ripper

I'm well aware of additives in the fuel system. I drive a diesel for pete's sake haha. I can't run acetone but lot's of guys running 2stroke motor oil in their diesel application (VE and VP44 pumps more than anything). ATF is plausible cleans and lubricates seals well. But it doesn't have good high pressure lubricity for flat tappet motors IMO it breaks the oil down and prevents the film from protecting like it should.

The problem I have with all this Jazz of adding crap to the system is it's like adding oil stop leak chemicals to your oil. It swells the piss out of the seals stopping the leak. But it wears the piss out of the contact points and the next fill up or oil change the seals return and now you have a serious leak on your hands.

Your acetone works well cause what is left behind is varnishy dense liquid, and Acetone just happens to be the perfect thing for disolving varnish and tar like substances. Small doses won't hurt anything but it's hard for me to rationalize how such a small amount can help anything either. It's like eating junk food, a little won't hurt, but where's the pleasure in a little?! Too bad too much will eventually kill you xD


Edit: I'm not arguing any points I completely agree and think your links support the topic well!

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Gt2256v, FMIC, Port & Polish Head, Stage 2 Colt Cam. Rosten Rods, PD150 Pistons, Oil Cooler, Fuel Cooler, Diablo W/M kit, Built 5 speed with LSD
I work on enough GP's to know I don't want to own one =P

Wait, you said you didn't notice any difference (even though less knock is a pretty big thing) then post an entire article about how acetone increases MPG. I'm confused by your tactics

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Dubs:00 VW GTI VR6, Low and Slow 91 VW GTI 8v, Shave the Bay!! 91 VW Cabriolet 8v, bitch Basket
GP's:04 GP GT, Past now G-Ma's Girlfriend's 97 GP GT, "Project Pink Power"

he said he had less knock!!! sheesh tough crown on these interwebs!

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Gt2256v, FMIC, Port & Polish Head, Stage 2 Colt Cam. Rosten Rods, PD150 Pistons, Oil Cooler, Fuel Cooler, Diablo W/M kit, Built 5 speed with LSD
I work on enough GP's to know I don't want to own one =P

And that would be a noticeable difference IMO. Not trying to start anything, I do enough of that already, just trying to figure out what he meant by that.

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Dubs:00 VW GTI VR6, Low and Slow 91 VW GTI 8v, Shave the Bay!! 91 VW Cabriolet 8v, bitch Basket
GP's:04 GP GT, Past now G-Ma's Girlfriend's 97 GP GT, "Project Pink Power"

Ehhh I meant to add 'Didn't notice any performance gains/increases'. I am hopped up on Redbull, and as if my memory/train of thought wasn't poor enough .

Butt-dyno wise I didn't notice any change. MPG and reduced knock were definitely noticed. Just no performance gains. It wasn't 'OMGWTFBBQ I JUST GAINED 10,000 HP!!!"#@, like some tend to over-exaggerate.

-- Tue Nov 22, 2011 4:46 pm --

And I agree wholly about the additives, and stop-leak 'solutions'. I don't use any of them. If I know a gasket, seal or anything like that is going out, I take the part off, replace said seal/gasket, and replace initially removed part. No use in putting a band-aid on a gaping chest wound, ya know?

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Jay - 99 GP GT, MOST options, no HUD or leather... Meh...

Xbox - b00nd0ck xs41nt

I makes musics... http://soundcloud.com/dj-jack-ripper

Haha, I gotcha now. Just by the sound of the first post it sounded like it was completely pointless to do type of thing.
Besides, everyone knows you need at least a stick on hood scoopand an aluminum wing to obtain the mystical 10,000eleventybillionHP.

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Dubs:00 VW GTI VR6, Low and Slow 91 VW GTI 8v, Shave the Bay!! 91 VW Cabriolet 8v, bitch Basket
GP's:04 GP GT, Past now G-Ma's Girlfriend's 97 GP GT, "Project Pink Power"

I've always ran premium ...it looks like it lasts a bit more too ...idk lol

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