Gas mileage
11-19-2007, 10:28 AM
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Gas mileage Well my 02 car has never really gotten the mpg that my 99 pulled.
I took my first road trip in several years this past weekend and the car only did 20mpg. What the hell. Any suggestions?
I have 4.10's, 224,224, headers. I drove 74 all the way and not really getting on it that much.
Any thoughts?
I took my first road trip in several years this past weekend and the car only did 20mpg. What the hell. Any suggestions?
I have 4.10's, 224,224, headers. I drove 74 all the way and not really getting on it that much.
Any thoughts?
11-19-2007, 10:43 AM
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it's those 4.10's, they're not meant for gas mileage. and is your car an A4 or M6? I have 2.73 gears and with the A4 I got maaaybe 28mpg highway doing about 80. I swapped to an M6 with the same gears and even with my 228/222 .558 cam, lt headers, ory, corsa cat-back, fast intake manifold, I still get over 32 average on the highway doing 80-85. of course they're 2.73's but I'm sure if I went to 4.10's it would really decrease my gas mileage.
11-19-2007, 10:49 AM
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Yes it is a m6. I guess it is the gears. I was turning about 2000- 2200, but man I didn't think it made that kind of difference. My 99 with 3.42 got 26 - 27mpg.
11-19-2007, 11:07 AM
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it is a good thing I don't drive it daily or on road trips anymore. I guess I will have to cruise a little slower next time.
I do need to change my fuel filter and clean the maf with some maf cleaner.
I do need to change my fuel filter and clean the maf with some maf cleaner.
11-19-2007, 11:40 AM
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20 mpg sounds about right to me w/ 4.10 and cam and doing 75mph
just be glad you dont have an old sbc motor youd be say why hw am i getting only 10mpg?
just be glad you dont have an old sbc motor youd be say why hw am i getting only 10mpg?
11-19-2007, 12:05 PM
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400 more rpms at highway speed is gonna do that for you....not to mention the cam.
was the car street tuned or just WOT? that could pick up a little mileage.
but honestly...what were you expecting?
although my cammed car gets 25-26mpg with stock gears (m6) doing 75-80mph. and my part throttle tune is horrible.
was the car street tuned or just WOT? that could pick up a little mileage.
but honestly...what were you expecting?
although my cammed car gets 25-26mpg with stock gears (m6) doing 75-80mph. and my part throttle tune is horrible.
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11-19-2007, 12:25 PM
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Those gears will change your MPG..LS series engines are not hard on gass till you get them above 2000 RPMs..when my car was stock I got 28-29 MPH on the highway..after the H/C and mods it still gets about 26. When I ran 4.10s for about 40,000 miles my MPG went down to 22.
11-19-2007, 12:28 PM
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You may gain a couple MPGs if you spent the time to "street tune" the VE table and MAF tables for maximum efficiency. I picked up about 3 MPG on avg and 5 on the freeway when I did mine. But it took a decent amount of time.
11-20-2007, 02:53 PM
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Well I have to agree. I did decide to get some maf cleaner. It was a little dirty and thought that may help some. If not, I hope it at least may do something at WOT!
11-20-2007, 02:57 PM
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400 more rpms at highway speed is gonna do that for you....not to mention the cam.
was the car street tuned or just WOT? that could pick up a little mileage.
but honestly...what were you expecting?
although my cammed car gets 25-26mpg with stock gears (m6) doing 75-80mph. and my part throttle tune is horrible.
was the car street tuned or just WOT? that could pick up a little mileage.
but honestly...what were you expecting?
although my cammed car gets 25-26mpg with stock gears (m6) doing 75-80mph. and my part throttle tune is horrible.
11-20-2007, 04:16 PM
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Oh I do enjoy the gears and will not go back. I really on drive the car from time to time in town and almost never on the road. I have hp tuners for the car, but does anyone know how to tune with that program? I would love to learn.
11-21-2007, 09:32 AM
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If you already own HP Tuners you're at least halfway there. Look on their forum, what you want to do is VE (volumetric efficiency) and MAF tuning. Since your car has a tune you should really just focus on the "cruising cells" to get better mileage. You can do this type of tuning without a wideband using long term fuel trims (LTFT) but it is a lot easier and faster with a wideband.
11-22-2007, 09:41 AM
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I make sure you speedo is set correctly. I know I got that with 3:42 gears. I did find my tire size was incorrect so I should have had a few more miles over the trip, but I do think there is some in town tuning needed.
11-22-2007, 04:32 PM
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IF a tune is COMPLETE (including part-throttle), the highway miles should be extraordinary compared to the city miles.
All extreme motor mods just make it a more efficient breathing machine. On the highway with far greater momentum than the stop-and-go of city driving, one will reap the gas-mileage benefits of that efficiency . . . IF the tune is COMPLETE.