Thread: Fuel usage improvement after ECU re-map

Originally Posted by shack

Have you actually calculated the result yourself?

If not, it's worth doing - as a lot of tunes are done in such a way that they will show better economy but actually be worse.

If it IS actually better... Good for you!

Cheers
James

Curious how they do that? My D4 already reads about 2L/100km better than the actual measured fuel usage. Are you saying that it tricks the trip computer into reading even more inaccurately?

I'd be super keen to get a remap if someone could guarantee reduced fuel usage. I definitely don't need more power or torque from my SDV6 but I would love better economy around town especially.

Originally Posted by Birdboy

Curious how they do that? My D4 already reads about 2L/100km better than the actual measured fuel usage. Are you saying that it tricks the trip computer into reading even more inaccurately?

I'd be super keen to get a remap if someone could guarantee reduced fuel usage. I definitely don't need more power or torque from my SDV6 but I would love better economy around town especially.

For my return trip from Coonamble back to Bathurst, I wanted to compare the trip computer fuel usage towing the van compared to a manual calculation based on fuel usage for distance travelled. I filled up chokkers at Coonamble and filled up at Orange on way home (last easy garage to pull in with van). The trip computer was reading an average of 14.1 l/100km (so similar to the outward trip which gave 13.9). My manual calculation gave a fraction over 16l/100km. It could well be that the trip computer has always been reading lower than actual but that's what I have just always used.

I realise it's just one trip and hardly a long term travel calculation, but am I using less fuel than before? Yes, without a doubt. From a full tank at Coonamble I still had over 1/3 tank left in gauge when I refuelled at Orange. I would have easily gotten home on one tank. I never have been able to do that before. Yes, it's just anecdotal, but just based on this one trip the fuel usage is a lot less (even if the trip computer is not accurate). Also just travelling around town I'm filling up less. Will be able to ascertain later when I do a longer trip and get true consumption.

End result, trip computer may not be accurate, (don't think the re-map has anything to do with fudging the trip computer). Am I using less fuel towing, absolutely. Seems like about 1.5-2.5 litres less per 100km. Also gives me greater range in vehicle alone and when towing. Also, the power application is very smooth when towing, (not that is wasn't before) but it is noticeably smoother. Also the blanking of the EGR was a bonus for future issues. Oh, and NO LAG at takeoff. I really hated the acceleration lag at startup, very noticeable before at roundabouts for instance. Now virtually none.

Originally Posted by Briar

End result, trip computer may not be accurate, (don't think the re-map has anything to do with fudging the trip computer). Am I using less fuel towing, absolutely. Seems like about 1.5-2.5 litres less per 100km. Also gives me greater range in vehicle alone and when towing. Also, the power application is very smooth when towing, (not that is wasn't before) but it is noticeably smoother. Also the blanking of the EGR was a bonus for future issues. Oh, and NO LAG at takeoff. I really hated the acceleration lag at startup, very noticeable before at roundabouts for instance. Now virtually none.

I had a remap and EGR blanked a couple of months ago by my regular indie here in Sydney who services my car. Immediately noticed the same sort of results as you. I don't own a van so can't comment about towing. It's early days but I do run a fuel app on my phone so I know consumption has reduced. I do the worst kind of driving in that it's mainly short 5 to 10 kilometre trips so it's quite noticeable. Haven't had the chance to long drive yet but am looking forward to seeing what the car does in that case. Lag has gone

Martin

A lot of commercial tunes seem to concentrate on lengthening pulse width, but doing so without the correct calibrations, so the ECU requests 50mm3 of fuel, but instead it delivers 60, so the AFR is messed up.

Some cars have a fuel use PID, some may calculate from injected fuel, and then others use mass air flow and calculated AFR, but all of those are useless if an injector duration has been lengthened, or the rail pressure has been increased, but the other table data not fixed.

Having said that, a lot of modern cars are running compromised tuning in an effort to reduce NOX emissions, if some of that tuning is corrected, you may well get better economy.

If you make more power and use it, you will burn more fuel, there is no way around this.

Cheers
James

Yes, I will also say that I have been pleasently surprised on fuel use since Cambo remapped mine.
We have done 12000km or so on this trip, head winds, tail winds, dirt tracks, sealed and unsealed roads, towing and not, low range 4WDing the whole spectrum and while I have data for fuel used for the trip in the end there are so many variables that I just have to resort to "gut feeling" and it tells me it's about 1~2 l/100 better than it was on the last escape with the old tune.
While I actually don't care about the fuel use beyond the need for planning routes and refueling, the interest in the numbers is in my engineering DNA I guess, (just can't escape it) and for those of you who might find it interesting, in this 12000km so far when towing van (3.3t or so) I sit on 90kph, without the van what ever the speed limit and always it's conditions dependant. So, the numbers are 10.7 l/100km best, 16.7 average and 20.7 worst, 41 refills, 2008 lit and $3091 so far.
And, I am bloody happy with that.

Originally Posted by PeterJ

Yes, I will also say that I have been pleasently surprised on fuel use since Cambo remapped mine.
We have done 12000km or so on this trip, head winds, tail winds, dirt tracks, sealed and unsealed roads, towing and not, low range 4WDing the whole spectrum and while I have data for fuel used for the trip in the end there are so many variables that I just have to resort to "gut feeling" and it tells me it's about 1~2 l/100 better than it was on the last escape with the old tune.
While I actually don't care about the fuel use beyond the need for planning routes and refueling, the interest in the numbers is in my engineering DNA I guess, (just can't escape it) and for those of you who might find it interesting, in this 12000km so far when towing van (3.3t or so) I sit on 90kph, without the van what ever the speed limit and always it's conditions dependant. So, the numbers are 10.7 l/100km best, 16.7 average and 20.7 worst, 41 refills, 2008 lit and $3091 so far.
And, I am bloody happy with that.

Glad to hear your trip is going well.

Mine was the 2.7L D4.

There was certainly a nice increase in torque,the turbo lag almost vanished,and the vehicle was nicer to drive.

Fuel economy stayed about the same,i was pretty happy with that.