MPG after a remap, will it get worse?

My MPG after a remap was?

  • Worse

    Votes: 4 20.0%
  • Better

    Votes: 12 60.0%
  • The Same

    Votes: 4 20.0%

  • Total voters
    20
Dec 31, 2007
1,479
0
Reading
havent voted because I havent got one, but from what i have seen when driving normally most people's mpg has been better.
 

BoomhaueR

Wanna go fasterrrR
Oct 9, 2008
810
0
Exeter, Devon
Normally it should increase. Before I fitted my dump valve mine increased to around 27mpg average. Now it's about 25. This is a mix of all types of roads and includes spirited driving over a period of about a month.
 

drue1

Active Member
May 27, 2009
193
0
kent
i did not before the car was remapped and i still dont know now.if your worried about mpg then dont get a remap.any sort of engine mods will use more petrol
 

Mark300zx

Active Member
Apr 24, 2008
1,456
8
Surrey/SW London
i did not before the car was remapped and i still dont know now.if your worried about mpg then dont get a remap.any sort of engine mods will use more petrol

Not necessarily, only if you stick your foot down, I am talking about normal driving.

To make it more relevant I am talking about petrol cars, I know diesels MPG can benefit positively from a remap.
 
Last edited:
mine is slightly better on 'normal' driving, especially on long motorway runs.....I averaged 38mpg on the motorway the other day.

BUT, if you use the extra boost/power of the map then it will be worse at that point....

full throttle acceleration registers 4mpg for instance :rolleyes:
 

JamJay

California Bound
I get 37mpg regularly driving sensibly. With a balanced amount of light/heavy right foot, I average at 32-33mpg all of the time. If i'm heavy all of the time then 27-28mpg. Every car seems to adapt differently, mine gained a serious amount or torque and became quite economical.
 
Last edited:

225

Full Member
Feb 8, 2004
1,836
0
uk
Visit site
Mine was better on the motorway as you can leave it in sixth more and use the extra torque, however on a more interesting road its lower as you end up using the extra power and having more fun!
 

BoomhaueR

Wanna go fasterrrR
Oct 9, 2008
810
0
Exeter, Devon
I find mine's better ...... IF I behave ;)

I think everyone should improve when driving carefully, and foot down it should be much worse. But then who gets a remap solely to improve mpg :D.

Just out of curiosity, how do you all calculate your mpg - do you trust the onboard computer or calculate manually? My figures for mpg always seem a lot lower than everyone else using the computer and I mostly drive like a granny on my daily commute.
 

dg-1984

Active Member
May 28, 2008
254
0
Glasgow'ish
Mine is not mapped yet something I am thinking about in the future. I'm driving like a granny for this full tank just to see what average MPG I can get and how many miles from the tank, changing gear at roughly 2K and averaging 40MPG, its so boring and cant wait to fill up so can drive normally again :D
 

bizzaboy

Guest
This is pointless - the reason you go for a Remap is because you want increased performance, you want your car to go faster !

If you are concerned about fuel economy then perhaps you should not consider a remap. However, when driven carefully, as pointed out by most of the companies that provide them, fuel economy might improve a little....

....until you put your foot down (again), and it will be even worse than it was before. ;)
 

turbin

Guest
depends on your right foot. Same driving style should give a slight better mpg as a remap calculates with more heat energy from the fuel.
 

flak monkey

Active Member
Depends on your driving style. If you get a remap and drive everywhere with your foot to the floor it will get worse.

At the end of the day you need to burn the fuel to generate the power, more power = more fuel - up to a point. The optimum AFR for max power is 12.5-12.7 but cruising you might be up around 17 or 18 for instance. BUT it can also mean using less fuel around the cruising areas of the RPM range, so you may notice a slight improvement on long journeys, but a definate decrease on shorter ones.
 

flak monkey

Active Member
I should think they do. Most run a closed loop for 90% of the time though as it allows target AFR's and advance figures to be hit throughout the rev range more easily (essentially gives you an adpative fuel table depending on what sort of fuel you have filled up with)

About the only time they might run open loop is at WOT and cold start
 
Progressive Parts, performance parts and tuning specialists