worst mpg after reflashing?
#1
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worst mpg after reflashing?
I might just be ignorant, but I brought my 8 to the dealership because the check engine light came on. The dealer couldn't figure out why it came on, but hours later said they fixed it. I asked how, and they said they reflashed the ecu and it fixed the engine light. I've driven two tank fulls now and getting about 20 miles less per tank than I was getting previously. I was getting about 230 miles per a tank (which isn't bad), but now i'm getting about 210. Any words of wisdom? Thanks.
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Re: worst mpg after reflashing?
Originally posted by true9baller
I was getting about 230 miles per a tank (which isn't bad), but now i'm getting about 210. Any words of wisdom? Thanks.
I was getting about 230 miles per a tank (which isn't bad), but now i'm getting about 210. Any words of wisdom? Thanks.
Regards,
Gordon
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Yeah, what Gordon said. I noticed that the fuel gauge acted differently after the M flash - so don't go by what the gauge used to read before the flash. Calculate the mpg the right way. You'll probably find that the mileage hasn't changed, or has slightly improved (which is what I found).
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There's an entire thread on the gas guage changing behavior after the flash.
Mine no longer ever reads at the 50% mark. While driving on a long trip it actually jumps straight from a notch above halfway to a notch below.
Mine no longer ever reads at the 50% mark. While driving on a long trip it actually jumps straight from a notch above halfway to a notch below.
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Another thing to consider is that to prove the M flash was successful, they tap the brake 20 times in 8 seconds (or so) and then the oil gauge sweeps.
This also resets what the ECU has learned and your car is like new again; my first two tanks after the M flash were not so great either, then it improved by 2 mpg.
Note that I'm not sure about this ECU resetting; I've never figured out what and how the ECU learns anyway.
-Peter
This also resets what the ECU has learned and your car is like new again; my first two tanks after the M flash were not so great either, then it improved by 2 mpg.
Note that I'm not sure about this ECU resetting; I've never figured out what and how the ECU learns anyway.
-Peter
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IT's pretty common for many cars to get worse gas mileage after you reset the ECU and it can take several days for the ECU to relearn everything and get back to it's old ways. At least this is what I've heard from various car owners, I've never experienced it myself since I don't even monitor my gas mileage.
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My mileage went up from 16.3-16.9 to 18.3 to 18.9 in the same every day mileage. I just set my trip mileage button when I gas up and divide by the gal. It may take a while for your car to adjust, although mine was immediate on the first tank.
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