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for those of you who hate reading about MPG posts, don't read this................. after finally snapping at 20-21 MPG on freeway driving ONLY, i had enough. something must be up with my car. i couldn't do anymore to get it to do better. 70-75 mph with steady throttle useage, short shifting (M6)very little hills where i live, and 93 octane top brand gas. nothing has made any difference. i took it in and they told me that they probabaly wouldnt find anything wrong as no codes have been thrown and that some engines just are not as efficient as others. bull****!!!!!! please. 5 mpg less than what they say is the average highway mpg is rediculous. something is wrong. if they can't find anything, i will be getting pontian rep down there. this is stupid and can't be right.
 

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One thing would do is dyno it see if it not running up to spec

Also what are you using to get these figures ? The cars computer may be off.
But I think it is runing to rich. It might just be the heat, ls2 hate the heat.Try some fuel injector cleaner check the timing. But if you are babying it like you say somthing is really wrong!
 

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enjracing said:
for those of you who hate reading about MPG posts, don't read this................. after finally snapping at 20-21 MPG on freeway driving ONLY, i had enough. something must be up with my car. i couldn't do anymore to get it to do better. 70-75 mph with steady throttle useage, short shifting (M6)very little hills where i live, and 93 octane top brand gas. nothing has made any difference. i took it in and they told me that they probabaly wouldnt find anything wrong as no codes have been thrown and that some engines just are not as efficient as others. bull****!!!!!! please. 5 mpg less than what they say is the average highway mpg is rediculous. something is wrong. if they can't find anything, i will be getting pontian rep down there. this is stupid and can't be right.
How many miles you got on that thing? It seems like I never got 22-23 until I had at least a couple grand on her. The last few tanks I've gotten between 16-18 if that makes you feel any better. But it wasn't because of an engine problem...it was a foot problem :rofl:

Good luck getting them to jump through hoops to fix your 400 HP car that won't get over 21 MPG too :cheers

Gerry
 

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Average around 24 MPG open highway for me. And mid to high teens around town. Its hot down here this summer and I only have 3500 miles on the car, so it seems about right.

Make sure that you measure it the old-fashioned way, the fuel usage and milage numbers on my computer display are way off.
 

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enjracing said:
thanks buddy. yeah, i tried all that. what are you getting highway only?
Hey bro.....I'm not even broken in yet at 280 miles so I will have to post up at a later date. I posted HotRods info because he is at 10k miles but did note that his MPG improved at higher MPH. Also as a former service manager/machinist I have to put in my 2 cents as it is entirely possible that your motor is very tight. Meaning that given the max and min tolerances for any given component, your engine falls in the minimum catagory, your engine would therefore be considered tight (more friction,less mpg) although it falls within acceptable standards at inspection.(The important question here is what are the qualifications of the inspector??) Although I am not a GM inspector I am sure there are many more qualified persons here that can expound on this topic.
 

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Straight from the Pontiac website:

Actual mileage may vary with driving conditions--use for comparisons only.

With a tune I still only get around 22/23 mpg average so I really don't know why you are still complaining about the gas mileage. If your car is not throwing any codes you're more or less wasting you time by calling a Pontiac rep. Go get it tuned and see what happens then because it's true that these cars are tuned rich from the factory.

Now what are you going to do if you don't get any cooperation from GM about this? Because according to the statement above from their website they don't have to do anything... period!
 

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I drive the LS1, so I know there is a small difference in the estimated mpg, but I just took a round trip from Dallas to Phoenix and I got 27.4 mpg for the trip while cruising between 80-85. But with regular daily driving I get about 22-23 even with mostly highway driving. I just can't believe that your 6.0 litre 400 horsepower muscle car ONLY gets 21 mpg. Maybe you should trade your GOAT for a Cobalt...I'm sure that you could squeeze 30 mpg out of that. I hear that the Civic hybrid is pretty nice too.:lol:
 

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enjracing, it's to bad the car doesnt come with a tissue holder, so i have a plan, how about you sell me your car, tell me how much. Hell, i'd drive the damn thing without crying if it only got 10mpg, so PM me and let me know. I'd be glad to take her off your hands. :rofl:
 

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How many miles do you have. After 10,000 miles it gets better. I have an 04 with the LS1. I got 27.2mpg on a 400 mile trip. However now I'm back in town, and I'm getting 12.7mpg. Ouch. Oh yeah, did I mention that I need new tires at 13,000 miles. I think I should take mine in, because tires should deinitely not wear out that fast.:D
 

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all **** talkers can blow me. the car has 5,000 miles on it. the bottom end will be loose enough now to at least get decent mileage. there is a problem. bottom line. like i said, if you don't want to hear about it, dont read it, and shut up. anyone with any class that has constructive ideas, i welcome your replies.
 

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enjracing said:
all **** talkers can blow me. the car has 5,000 miles on it. the bottom end will be loose enough now to at least get decent mileage. there is a problem. bottom line. like i said, if you don't want to hear about it, dont read it, and shut up. anyone with any class that has constructive ideas, i welcome your replies.

Dude, you know I have no problem with you first and foremost- but your mileage is no different than the rest of us from what you say. Yes, some people hit "optimum" conditions and do better, but that is the exception, not the norm. SAying there is a problem with the car is not going to get anything done. As long as there are no codes, the dealer can't do anything about it. The only one who can is a good tuner with a dyno- they can optimize your A/F ratio for better performance and/or economy. I wish you luck, but I kind of think you are pissing in the wind with this one.
Joe
 

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Maybe you should just sell your car. Check the Pontiac website. The M6 is rated at 17/25**.

**Actual mileage may vary with driving conditions - use for comparisons only.

You say that you drive only on the highway? Are you trying to tell me that you back out of your garage and on to the highway, and once you hit the highway, you don't have to accelerate? And when you exit the highway you just roll into a parking space? Why did you even buy a GTO? The rest of us are out there DRIVING our cars, not crying about 2-3 mpg. That 2-3 mpg that you are not getting has cost you less than $100 since you bought the car...And I'm sure that GM REALLY cares that you only get 20-21 mpg. If there are no codes saying that something is wrong, how can YOU prove there is? Driving a GTO a bitching about fuel economy is not the smartest thing you have ever done.
 

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You're insane guy!!! INSANE you're getting 21-22MPG on a 400HP 6.0 litre V8 muscle car. What the hell do you expect, seriously! I mean what do you think 93-98 vipers get for gas mileage, how about SRT10, MY FREAKIN ACCORD w/ a 4 banger averaged 27-28 MPG...I think the EPA rating was like 33, damn I must have got one over on the pontiac dealer I traded that lemon into for my GOAT, the gas mileage was off by 5 MPG sheesh THERE HAD to be SOMETHING wrong with it!!! You have a car that doesn't have to be even nudged to get movin, looks awesome, is rare, and has a vette engine...All those MPG statements are BS
 

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enjracing said:
all **** talkers can blow me. the car has 5,000 miles on it. the bottom end will be loose enough now to at least get decent mileage. there is a problem. bottom line. like i said, if you don't want to hear about it, dont read it, and shut up. anyone with any class that has constructive ideas, i welcome your replies.
I think everyone needs to relax. Nothing wrong with wanting to have power and good mileage. It may be a little unreasonable to expect GM to do anything about a 400 HP car that's getting over 20 MPG on the highway, though. I'm afraid the service manager is going to laugh at you.

That said, I'm one of the ones that has been getting good mileage on the highway (24-25mpg). However, the wife and I took a road trip to Richmond the other weekend; 90 miles all Interstate, and I only got 22 mpg. It was 95 degrees, and we were running the a/c, so I was OK with it.

Funny, I filled up the other morning before coming to work, picked up a friend, and did my usual conservation coming down the mountain, by coasting. (I did have to drive up the mountain as well). When I got to work, which included going trough 20+ traffic lights, most of which I hit green, I was averaging 29mpg. Unbelievable.

By the time I got home, and dealt with rush hour traffic through that same 20+ light stretch, I was at 22 mpg, so I lost a lot in the stop and go.
 

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When I first bought my car ('05 6spd w/ 1300 miles) I drove 1700 miles to get it home. Over all I got anywhere from 26 to 28 mpg doing an average of 85 mph with the a/c on. Since i've had it home, I don't think I've gotten over 16 mpg (mostly short trips and can't get away from the throttle!).

I've come to the conclusion that you must have all the correct elements to get optimal mpg and it's just not worth worrying about... or you won't enjoy the car.

My car is killing me on gas because I get the kids in it to go for a ride just to hear the exhaust rumble...not a reason in the world to go anywhere!

But I love my car. May sell it tomorrow but I'm going to enjoy it while I have it.

Good luck and hope you find peace with your dilemma.
 

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My friend bought a Vibe. His brother works for GM so he got the family discount etc. Needless to say he was pissed when he got significantly less mpg than posted, and let his brother know it.

his commute is from his apt in manhattan to his cabin in phonecia, mostly highway. His V6 mustang 5 spd got better MPG, and i believe the vibe was listed as getting better mpg.

He bought the pontiac to help his brother. needless to say, he will speak with his $$ when he buys a non gm car for his next car.

I believe you have a valid complaint because you purchased the car believing you would get something close to what is advertised, and close to what others are getting. Valid complaint yes. Getting results from GM - next to impossible.
 

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Tom said:
My friend bought a Vibe. His brother works for GM so he got the family discount etc. Needless to say he was pissed when he got significantly less mpg than posted, and let his brother know it.

his commute is from his apt in manhattan to his cabin in phonecia, mostly highway. His V6 mustang 5 spd got better MPG, and i believe the vibe was listed as getting better mpg.

He bought the pontiac to help his brother. needless to say, he will speak with his $$ when he buys a non gm car for his next car.

I believe you have a valid complaint because you purchased the car believing you would get something close to what is advertised, and close to what others are getting. Valid complaint yes. Getting results from GM - next to impossible.

Wow this is really suprising, a reply from Tom that bashes GM. :rolleyes:
 
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