mikischu

Hi Everyone.

Just thought I'd share this with you all.

Recently my car was getting a bit thirsty. I went from about 10.9L/100Km to about 13.9L/100Km. A bit later my MAF also threw an error and ended up needing to be replaced.

After the replacement, my fuel economy still didn't improve. Even on long cruises, the economy was still pretty crap.

So I tried the ECU reset procedure (ignition on, step on the gas pedal, ignition off, release gas and then wait). The difference was instant!

I went back to about 10.9L/100Km in city driving (I live in Hong Kong and traffic here is murder) and today on a drive out to the airport, I got down to just 8L/100Km. I suspect that it could have gotten even lower if not for a bit of traffic I hit.

As an extra benefit, my car also doesn't seem to be shifting gears as erratically too.

So, the moral of the story is, an ECU reset may help you improve your fuel economy. Hope others may find this useful.

Rudeney

FYI, that's not an ECU reset - it simply erases the driver-adaptive learning of the TCU. If you continue to drive in the manner that you always have, it will eventually re-learn your driving style and go back to the way it was.

Glyn M Ruck

+1^

Albysoo

Mikischu, after the ecu reset, were you able to keep the good mileage? Ie. 11 lt/100km? My s350 is averaging at. 16-17lk/100km. Which is no where near right, I have changed the MaF SENSOR. BUT no improvement, so doing the ecu reset. Hope it helps, let me know if there are other things which help improve mileage. Thanks!

user 823908234

Of course, this thread is ~2.5 years old, but I've said it before and I'll say it again:
when I drive somewhat 'aggressively', my mileage gets better by 1-3 mpg. This has been consistent for years. Yes, it does, and fine with me! No one can explain.

Rudeney

Quickly accelerating to your cruising speed will result in better MPG than slowly accelerating. Of course this doesn't mean "flooring it" from a takeoff, just not driving like a grandma. Oh, and it's only valid for when you reach and then stay at a fairly constant cruising speed - if you run 0-60-0 between traffic lights, you're going to kill your economy.

user 823908234

Rudeny, you are right of course, it seems logical... but this flies in the face of logic.
I'm just talking about the humdrum stop-and-go; pushing it between lights, maybe a little fishtailing, and that trip gets a better reading.
Wife has been driving it for the last month, and doesn't drive "like me", and mpg is predictably lower. Around here I rarely have an opportunity to go more than a couple of blocks before stopping again, with speed limits of 35, 45, 50. 'Normal drive' ~17; but push it, then ~18.5-19. All my info is just determined trip-by-trip on the dash computer, though.
Get ~25 if I can keep it at speed for at least several miles, so in that regard you are correct.
I hope it's not just me trying to justify 'hot rodding'! In any case, I'm not complaining...far from it!

And Rodney, thank you for all the super information and help you always offer to the members. Priceless! Uh, is this forum your full time job?
Most respectfully, and I mean it,
Happy weekend!
Jerry

Rudeney

If you're hammering it between lights, and slamming on the brakes, then I'm surprised you're getting better MPG. But if you're just hammering on start, then backing off the accelerator almost immediately, then that's pretty much how it works - WOT when the engine is doing its hardest work give the best economy.

I get in my wife's Jeep GC and it will show 16.. After I drive for just an outing to dinner, accelerating more aggressively, it's up to 17-18mpg.


If you stay on the throttle through higher speeds, you'll kill it. If you ever get a change to do any 100mph+ driving, you'll really see it suck some fuel.

I should be so lucky to have such a great job! No, just a hobby!

user 823908234

Well, keep it up! Thanks again!