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Discussion Starter · #1 ·
i absolutely baby my throttle pedal, short shift and skip gears, go 70-75 on the highway, rarely jump on the gas, do 85% of my driving on the highway, and i still am only getting about 20-21 MPG average? my car is bone stock too? what the hell is going on here? should i take it in for a diagnostic?
 

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I cruise at 90-95 and get 26 mpg. You should be getting better at 70-75. Do you have the auto or standard?
 

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enjracing said:
i absolutely baby my throttle pedal, short shift and skip gears, go 70-75 on the highway, rarely jump on the gas, do 85% of my driving on the highway, and i still am only getting about 20-21 MPG average? my car is bone stock too? what the hell is going on here? should i take it in for a diagnostic?
+1
I don't rev the engine, I drive mostly highway doing 80 or less, and I'm getting around 17mpg average. I have a 6M.
 

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I don't get it either- I took my car on a 200 mile trip the other day and set the cruise at 72 just to see if I could do what others are doing for MPG's and I got 22 round trip lol. I can't wait to see what it goes to with the procharger on it hahaha.
Joe
 

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Drivers on here have reported a wide variety of mpg on their engines..... MANY have stated they use a quart of oil between 3,000 mile oil changes. I checked my oil level before I got my 28.4 mpg and my oil level was still full at 4,000 miles driven. This tells me our engines are not created equal.

Even though I did get the MPG I stated, town driving is a different story. I get as low as 16.5 or so to a high of 19 in "city" driving, depending on the circumstances. Overall driving highway and city I am at about 19-20 tops.

Highway driving at the figures I gave was pure highway. Filling up and jumping right on the turnpike, NO interruptions and at a steady pace. I tried to maintain a 70mph, and I did for the most part. When my trip ended the average speed read 62.5 or so mph and 28.0 mpg. NO stops, except getting off the exit and a couple of stop signs.... but overall, my math and the cars computer were right on when I refilled and checked the miles driven against the gallons used.

Again.... our engines are not created equal.
 

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I think there are a lot of factors that affect MPG, and those that are reporting mileage that good are driving under the ideal conditions. Terrain, traffic, altitude, octane of the fuel, etc. can cause your mileage to go down.

I've been using 92 octane most of the time, and have been driving back and forth between the St. Louis airport & Festus. I follow dip****s who cause me to break stride all the time up and down hills, and I get frustrated, have to pass in the right lane, and such. Plus, I don't baby this thing. I do about like Groucho, and need to have at least a good 100 MPH run every day. The rest of the time, I'm cruising about 50% of the time at 85-90, and the rest doing 70 thanks to the "left laners".

Having said that, I can STILL do all those, and drive for mileage...I just try to be smart about when I do what...and try to not ever use the brakes. I also do NOT leave it in 6th and dog the engine at all.

After break-in, my mileage dropped to just above 15, but I was also doing a lot of driving around town "Hey, look at my car!", but now, I drive mostly highway, and I'm up to over 19 average.

It sounds like you're right there with me, and I don't consider it abnormal. I only get 25 out of my 3.8 Bonnie driving similar, so I'm happy...and it runs well.

I do think it is funny that someone with the handle "enjracing" started a thread complaining about mileage :rolleyes:

Gerry
 

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GTO judge said:

Even though I did get the MPG I stated, town driving is a different story. I get as low as 16.5 or so to a high of 19 in "city" driving, depending on the circumstances. Overall driving highway and city I am at about 19-20 tops.
Sounds about like I'd expect. If I tok off, and was able to hold a steady 70 on mild terrain, I bet I'd get close to that. Where I live, that's just not possible even if I strap an egg to the accelerator.

Gerry
 

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enjracing said:
i absolutely baby my throttle pedal, short shift and skip gears, go 70-75 on the highway, rarely jump on the gas, do 85% of my driving on the highway, and i still am only getting about 20-21 MPG average? my car is bone stock too? what the hell is going on here? should i take it in for a diagnostic?
In this post http://www.gtoforum.com/showthread.php?t=8516 you stated your skip shift has never came on in two weeks of driving the car. That could be a problem if you are getting on it hard on take-offs. Just a thought!
 

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There is a lot of variance, between the engines in our cars alone, plus all the other factors (how hilly/flat it is where you drive, the temperature, how much you weigh and how much cargo you carry, etc).

One other thing--I've heard a few complaints that the computer mpg calculator in our cars is off for some people (but is correct for others), so I'd recommend hand calculating the mileage at least a few times to see how what you get compares with what the computer says. Also keep in mind that unless you do some sort of reset (can someone else give more info on this?) the reading on the computer is the average overall from when the car was produced.

That said, I do not know what I get for highway mileage :( Since having my GTO, I've not made any trips, and most my driving is normal daily driving, which consists of mostly city-type miles. I also usually take short trips (15-20 minutes) which is not ideal, and can rarely use cruise control as there is too much traffic fluctuating in speed, and too many stop signs/lights. I usually drive conservatively for around-town driving, and tend to get low 16s, though right now it is reading 15.8 due to some recent shorter trips.
 

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I live in in a very hilly area, there are tons of steap climbs when i get on the highway but i am also at 7'000 feet so i have less power, alot less power(70 to be exact) so that is most likely why i get a decent MPG at 90. At sea level i know i would not be getting near as good as i get here.
 

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enjracing said:
i absolutely baby my throttle pedal, short shift and skip gears, go 70-75 on the highway, rarely jump on the gas, do 85% of my driving on the highway, and i still am only getting about 20-21 MPG average? my car is bone stock too? what the hell is going on here? should i take it in for a diagnostic?
I have the automatic and under normal driving conditions around town and short trips in the boonies I average 17 to 19 mpg. On extended trips at 75 to 80 mph on the interstate I have touched 22 mpg on occasion but it generally comes in at 21 mpg.

I don't consider this bad mileage at all considering what's under the hood and the auto.
 

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Discussion Starter · #15 ·
here's the sad part..............my commute is all flat terrain in charlotte, nc, where the altitude does not hurt HP. it is pretty damn humid and hot though now, so maybe when it's not like this, my mileage will improve a bit.
 

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19-21mpg........all the time. Running a Maggie, LT's, etc. It's all good........


JET
 

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I recently made two round trips between Augusta GA and Charlotte and calculated the milage manually each way. Best was 24.5 MPG running at 75-80. I had to slow down a bunch one trip due to very bad weather (constant hard rain most of the way) and milage was the worst at 22.5, go figure. Maybe faster is actually better?

My computer is off by around 5-10% (fuel usage reported is much higher than actual).

I generally drive 50:50 highway/city, and my reported milage has been hanging around 18. Just driving around town I could believe well below 15 MPG would be normal.

M6, bone stock with just at 3000 miles...
 

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My 05 with an automatic on the highway averaged 21.8 at 79 mph with the cruise set. In town its getting 14.9 average.
I don't know about G.M. but Ford if you take your vehicle in for a warranty issue and there are any computer updates, the dealer automaticaly installs them, and in the case of a friends 6.0 diesel Excursion the mileage dropped from 14.0 in town to 10.5 and he's claims that it runs like a total pig compared to performance before the update. Ya might check with your friendly service advisor and check if there have been any software updates to your vehicle.
 

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2 fill ups, what ive experienced so far

I went from getting an average of 27-28 mpg w/ my 4 banger 5 speed accord, revving the PISS out of it, and could get as high as 32-34 w/ cruise control on the highway. That being said, I've opened up my new GTO plenty (it's broken in w/ 19,000) since I've had it and filled up twice and got right around 16 mpg. To me, this isn't bad considering I've done plenty of stop/go driving and accelerating heavy. I could see getting 20-22 driving sensibly only speeding once in a great while...I'm sorry but I can't imagine getting 28 mpg unless you were driving on a giant treadmill hahaa. I mean my neighbor has a C5 vette which is considerably lighter and he states his best gas mileage is like 25 with the planets alligned. I didn't buy this car thinking a 5.7litre american built V8 would sip gas like a corrolla. I also work w/ a GMC certified mechanic and master technician. In his 5.3 v8 chevy extended cab 4wd TRUCK he gets 20-22 mpg in mixed driving...he attributes this to a power chip and intake/exhaust setup. Maybe look into the same thing? I'm sure alot of people in here have that type of setup, does it help?
 
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