25% drop in fuel economy reasonable?
12-15-2000, 08:57 AM
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25% drop in fuel economy reasonable?
When I got my A4 three years ago I was doing 26mpg with mostly highway driving. It's steadily gone down and the last three or four months it's at 19-20mpg (also highway driving).
I've use the recommended fuel injector cleaners which help increase fuel economy 1-2mpg for about a month and then it's back down.
At what point is loss of fuel economy a real issue? I mean for God's sake this is a 25% decrease in only three years. The dealer always blaims oxygenated fuels and driving habits and says there are no problems just because the computer says there's no problem. I've had to use oxygenated fuel as well as 10% ethanol fuel since the day I bought the car (in denver).
I'm not convinced. What does the sticker on new A4's say they should get in city and highway? My highway experience of 20mpg I think sucks. The dealer won't do jack though.
Chris Murphy
1998 A4QM Pearl
I've use the recommended fuel injector cleaners which help increase fuel economy 1-2mpg for about a month and then it's back down.
At what point is loss of fuel economy a real issue? I mean for God's sake this is a 25% decrease in only three years. The dealer always blaims oxygenated fuels and driving habits and says there are no problems just because the computer says there's no problem. I've had to use oxygenated fuel as well as 10% ethanol fuel since the day I bought the car (in denver).
I'm not convinced. What does the sticker on new A4's say they should get in city and highway? My highway experience of 20mpg I think sucks. The dealer won't do jack though.
Chris Murphy
1998 A4QM Pearl
12-15-2000, 02:32 PM
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Hey, I'm getting 15-16 around town in my 1.8t Avant. (long)
But you should do better than 19mpg on the highway - even I can do 24 to 25mpg on the highway.
Here's another thing to think about. Several months back I started getting check engine lights. Before the check engine light, I had trouble starting the car after refueling. Turns out I had a bad EVAP purge valve. Dealer replaced the valve and my City mileage went up to 19mpg. Ok, then three weeks later they replace the EVAP cansister and guess what happens? Yep, my mileage is back down to 15-16mpg around town.
If your driving habits and conditions haven't changed and your fuel economy has suffered that much, then you are probably running rich or you have an undetected leak in the fuel system. You could have a marginal O2 sensor or some other problem with the emissions system. Have you checked your plugs, are they fouled?
Remember, the dealer is always thinking, "the ECU will throw a code if there's a problem." Not true. My A4 didn't start throwing codes until the problem got really bad.
Bitch at your dealer, call AoA and complain. I'm going to complain some more when I go back for my 15k service. If they do nothing, I'm going to call AoA and complain. 15-16mpg is ridiculous, as is your 19mpg for highway driving. Yes, it's true I make short trips (~3.5-4 miles), but I drive in a restrained manner, coast a lot, and I let the tip shift early too.
Nobody else I know gets this kind of crummy mileage in there A4, neither should you or I.
Here's another thing to think about. Several months back I started getting check engine lights. Before the check engine light, I had trouble starting the car after refueling. Turns out I had a bad EVAP purge valve. Dealer replaced the valve and my City mileage went up to 19mpg. Ok, then three weeks later they replace the EVAP cansister and guess what happens? Yep, my mileage is back down to 15-16mpg around town.
If your driving habits and conditions haven't changed and your fuel economy has suffered that much, then you are probably running rich or you have an undetected leak in the fuel system. You could have a marginal O2 sensor or some other problem with the emissions system. Have you checked your plugs, are they fouled?
Remember, the dealer is always thinking, "the ECU will throw a code if there's a problem." Not true. My A4 didn't start throwing codes until the problem got really bad.
Bitch at your dealer, call AoA and complain. I'm going to complain some more when I go back for my 15k service. If they do nothing, I'm going to call AoA and complain. 15-16mpg is ridiculous, as is your 19mpg for highway driving. Yes, it's true I make short trips (~3.5-4 miles), but I drive in a restrained manner, coast a lot, and I let the tip shift early too.
Nobody else I know gets this kind of crummy mileage in there A4, neither should you or I.
12-16-2000, 05:10 PM
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Re: Over 3 years what mods? Wheel/tires?
>Tire wear /air pressure?
I check tire pressure every two weeks. Changed to Kumho ECSTA Supra 712's a couple months ago and fuel economy is unchanged.
>Check brakes/emergency brake for drag?
I had a guy do an end warranty check up of the car and that didn't come up. Since I'm not satisfied the problem has been resolved I could get the dealer to check for this and see if it's a factor. (I hesitate to go back to that dealer because while in their care for two weeks to fix a few minor things before the end of the warranty, they put a dent in my oil pan which now leaks and they refuse to take responsibility.)
>How many miles on engine?
36,000 approximately
>Check turbo boost?
Not applicable (it's a 2.8).
Chris Murphy
I check tire pressure every two weeks. Changed to Kumho ECSTA Supra 712's a couple months ago and fuel economy is unchanged.
>Check brakes/emergency brake for drag?
I had a guy do an end warranty check up of the car and that didn't come up. Since I'm not satisfied the problem has been resolved I could get the dealer to check for this and see if it's a factor. (I hesitate to go back to that dealer because while in their care for two weeks to fix a few minor things before the end of the warranty, they put a dent in my oil pan which now leaks and they refuse to take responsibility.)
>How many miles on engine?
36,000 approximately
>Check turbo boost?
Not applicable (it's a 2.8).
Chris Murphy
12-16-2000, 05:13 PM
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that is really bad
Yeah I would have enacted the lemon law by now for that kind of mileage. I might end up doing that anyway, we'll see. If it had been 20mpg since day 1 and didn't go down by more than 1mpg over three years, I probably would have little or no case (well maybe I would because I think the mileage sticker says it should be 26mpg highway). But this is a 25% drop. It's nuts.
Chris Murphy
Chris Murphy
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12-20-2000, 08:33 AM
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Chris - it does seem something has changed.
1. Can we reset the ECU by disconnecting the battery for 20 minutes. That might be worthwhile trying.
2. Run a compression test.
3. The O2 sensor also might be a good place to look also.
4. If you are out of warranty like me - you might try a non dealer Audi repair shop and see what they say.
Reggie
98.5 2.8QMS (17K miles) I am getting 19 around town and 26 on the highway.
2. Run a compression test.
3. The O2 sensor also might be a good place to look also.
4. If you are out of warranty like me - you might try a non dealer Audi repair shop and see what they say.
Reggie
98.5 2.8QMS (17K miles) I am getting 19 around town and 26 on the highway.
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