GXP-MPG ?

[Arrowhead]

What does "LS" designate ? Which trim levels installed LS engines ?

[01bonneSC]

What does "LS" designate ? Which trim levels installed LS engines ?

http://en.m.wikipedia.org/wiki/GM_LS_engine

[Arrowhead]

Gotcha ! Thanks for the link.

[01bonneSC]

You can get Imps and GPs with an LS4, but again like the 3800s, the 4t65HDs are the weak point for horsepower mods.

[GXPete]

Don't take this wrong, but maybe you'd be better off selling the Bonne and getting something more economical. How much are you going to spend trying to achieve a few extra mpgs on a car that wasn't built for its economy? The Bonneville GXPs (or any of Pontiac's GXPs for that matter) are not economy cars. They're just about everything else though - nice, comfortable, big sport sedans, timeless in appearance and styling, loaded with bells and whistles, with all the kick-in-the-pants power you'll ever need, and an unmistakable roar when you put the pedal down. But if what you need is to get good gas mileage, which appears to be what you're saying, buying a large sport sedan with a huge V8 was probably not the best choice, no matter how low the mileage or price was. Most GXP owners (or maybe it's just me) didn't buy them for their great gas mileage.

Bottom line: You're crazy if you drive what drives you crazy.

[3800SERIESII]

In the "right" car a northstar v8 should get pretty good mpg. I have seen '93-'04 sevilles get consistent 18 mpg city and 28 hwy.

[dpnewfie]

Yes, but the caddie's are geared differently than the bonne as well. These cars were never meant to be economical. However, that being said; I consistently get 21-25 mpg. That is pretty good for a car of this size.

[Arrowhead]

Don't take this wrong, but maybe you'd be better off selling the Bonne and getting something more economical. How much are you going to spend trying to achieve a few extra mpgs on a car that wasn't built for its economy? The Bonneville GXPs (or any of Pontiac's GXPs for that matter) are not economy cars. They're just about everything else though - nice, comfortable, big sport sedans, timeless in appearance and styling, loaded with bells and whistles, with all the kick-in-the-pants power you'll ever need, and an unmistakable roar when you put the pedal down. But if what you need is to get good gas mileage, which appears to be what you're saying, buying a large sport sedan with a huge V8 was probably not the best choice, no matter how low the mileage or price was. Most GXP owners (or maybe it's just me) didn't buy them for their great gas mileage.

Bottom line: You're crazy if you drive what drives you crazy.

I truly do appreciate your heartfelt concern for my budget and psyche, however you really needn't concern yourself any further. I didn't buy my first THREE Bonnevilles with any real expectations for great gas mileage. I do want to get my newest and FOURTH Bonneville within the "norm" bracket, which at this point .....it ain't ! I didn't give a flyin' flip what mileage my 1968 Firebird convertible got ......especially after boring,cam,Holley and Thrush were brought online ! I'll become 60 years old this October (God willing) and I've had a number of vehicles since I was 16,all that aside, I can pour gas into this or any other car till the cows come home and it won't affect my finances even a little bit, I just want things to be "correct" and will pay handsomely to the right person to achieve that. Oh....I'm looking for another GXP to put in my barn as a parts donor too BTW. BTW..... my plain vanilla 2000 SLE has just about the same acceleration as the almighty Northstar GXP does, at this point anyway.

[dpnewfie]

Have you pulled the K&N filter yet? I know you said you were going to do that. And as far as plugs go; it's not an easy task on this car but it wouldn't hurt to pull one of the front four and see how it looks.

I suspect that you have an intake restriction. Just my 2 cents.

[sethjamesrimrodt]

My 2000 SLE had no guts compared to my GXP. There is something wrong with your GXP

[Arrowhead]

LOL....it could be a nest of field mice up in that beyotch !! I do have a refresh kit I got for my 88 GMC K2500, I'll do that check next. I Have never seen such a cramped engine compartment since I put headers on my old Datsun 2000 roadster ! I actually fabricated my own special tools for that nightmare !!

[Arrowhead]

My 2000 SLE had no guts compared to my GXP. There is something wrong with your GXP

I doubt it, my SLE is a screamer, a thirty year veteran GM mechanic mistook it for a turbo ! (not sure how he didn't pick up on the lack of "whine" !) FWIW...I'm not sayin' the GXP is a "pig", it just isn't "all that" either.

[LeSabre in Buffalo]

Get a bottle or two of this stuff: http://www.gumout.com/ourProducts/ReganeFSC.asp

Dump it into the tank, then fill up. Drive the car pretty aggressively. Repeat. It should get better. That stuff will clean out any carbon that's built up in the fuel system.

Also, for the first oil change, I'd change the oil with a full synthetic known for cleaning out engines like Pennzoil Ultra.

[nos4blood70]

My 2000 SLE had no guts compared to my GXP. There is something wrong with your GXP

I doubt it, my SLE is a screamer, a thirty year veteran GM mechanic mistook it for a turbo ! (not sure how he didn't pick up on the lack of "whine" !) FWIW...I'm not sayin' the GXP is a "pig", it just isn't "all that" either.

There's no way something with 205 horsepower should keep up or even be alikened to something with almost 280... Unless you've modified your SLE in any way, it shouldn't even be anywhere near the GXP's moving ability.

[Arrowhead]

Hi nos4blood70,
I really don't mean to perplex your views but, having owned and driven cars with 400+ HP I'm a pretty fair judge of torque, power bands, and acceleration traits in various rides. If my GXP is a hog compared to most others that were built, that'd explain a lot but, a neck snappin', light to light beast it isn't. It is a sporty lookin' bigassed, heavy4Dr. sedan with a decent amount of power. If I'd really wanted a true performance car, I'd probably have gone with an Aussie GTO or similar. These days all that concerns me is the ability to accelerate quickly when getting on a highway ahead of a semi, 1/4 mi./ET stuff is in my rearview. I recently test drove a 2012 Buick with a feeble 4-banger that couldn't get out of it's own way even if it's life depended upon it! A truly dangerous car, IMO. I'll give the GXP a few more weeks to straighten up............... before I send it to the crusher.

[01bonneSC]

The GXP was built as a highway cruiser, def not a light to light drag car. Do some 50-85 pulls to get that thing cleaned out. 22K on a 7 year old car def has some things that are a lil gummed up.