Increasing MPG with a remap

ajstan

ajstan

ajstan

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Take a Focus ST, from what I've read they struggle to top 30mpg even on a run. But they do seem to be ideal for remaps and plenty of people have done it and claim they get similar MPG with improved performance.

So my question is: Would it be possible to remap a Focus ST to improve MPG but retain the original performance?

If so, what kind of MPG would you expect to see?
 
its not something ive come across myself but youd have to factor whether the marginal saving could actually offset the cost of the software during the lifetime of you owning the car

alternatively, sell up and buy one of those tdci-dressed-up-as-an-ST models you see about?
 
The idea of improving MPG with a remap is down to you spending less time with the throttle open getting up to speed.

With a map you should, in theory, accelerate quicker then cruise along. In reality you'll just be hooning all over the place resulting in a much worse fuel economy.

I'd be interested in some real world remapped ST MPG figures as I can manage 32 MPG on a run @ 65mph but its dull as dishwater
 
I don't have one myself and I know it could be considered unusual thing to consider on a performance car. I was just interested. :)
 
I have a Focus ST, I got the mountune kit on it and it doesnt improve MPG at all and I didnt expect it to.

I dont think anyone can seriously expect better MPG from a remap, more power inevitably means driving quicker and more trips to the petrol station for raping by Clegg and Cameron.

I get about 20-22mpg on normal day to day short runs, I can get 33mpg on a run if your prepared to plod at 70mph. You can probably get 25-30mpg consistantly with mixed driving but you'd need to crawl everywhere and if you have an ST you dont really crawl anywhere.
 
Not quite sure why you would want to improve MPG but keep performance the same.

When I had my first Impreza mapped it was quicker and much better on fuel (30mpg no problem)
 
Five_Star said:
The idea of improving MPG with a remap is down to you spending less time with the throttle open getting up to speed.

With a map you should, in theory, accelerate quicker then cruise along. In reality you'll just be hooning all over the place resulting in a much worse fuel economy.

I'd be interested in some real world remapped ST MPG figures as I can manage 32 MPG on a run @ 65mph but its dull as dishwater
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Shouldn't this be you have to open the throttle less for equivalent acceleration after a remap? Accelerating quickly to speed is never going to be more efficient than slowly ramping up.
 
EddyPee said:
I get about 20-22mpg on normal day to day short runs, I can get 33mpg on a run if your prepared to plod at 70mph. You can probably get 25-30mpg consistantly with mixed driving but you'd need to crawl everywhere and if you have an ST you dont really crawl anywhere.
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This is exactly the same situation with my car, a 3.4l sports car :eek:
 
Had a fiesta st since last tuesday and i'm getting 32mpg average now, on tuesday i was getting around 12-13mpg when i first picked it up and went for a drive down country roads.
 
Mud said:
Accelerating quickly to speed is never going to be more efficient than slowly ramping up.
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The quicker I can get up to speed the better. Then just ease off and let the cruise control do it's thing. It's much more economical than crawling up to speed for me.
 
I'm fairly confident it was proved somewhere that there's no disconcernable difference in accelerating quickly to speed or slowly gaining it in regards to fuel economy.
 
My mates Leon 20VT gave better MPG on a run after a remap but you have to factor in the cost of the remap and if in reality you would drive sensible enough to claw that money back over time before you start seeing a benefit which is pointless when you think about how much the difference in fuel consumption could be pre and post remap inc the amount of time to get the money back
 
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I dont see why not, for instance the MR2 Turbo standard map throws so much fuel into the mix it went off the graph on my RR chart at something like 8:1
 
I think the idea makes sense, a remap giving you smoother delivery of power but in reality all it does is mean you hoon a bit more everywhere and that isnt going to help your petrol consumption.

Id suggest you dont buy a remap expecting better consumption as I dont think you will see that at all.

Id also suggest dont by a Focus ST unless you are prepared for it to munch petrol to a level that really should mean its a bit more supercar than it actually is.

After 4 years I can tell you ive never seen 30mpg on a tank when mixed driving, not even close.
 
my golf 1.8t (very similar straight line pace) to a 2.5 ST will do36-38 when driven sensible on a motorway drive.

WRT AFRs, engines that ive paid attention to run a fairly lean AFR upto about 3.5krpm and then richen up for component protection, so in terms of economy, it pays to keep the engine below taht threshold most of the time
 
On a diesel engine the Start Of Injection is, apparently, set before TDC which reduces power and economy but keeps emissions in check so there is a very real possibility of extra MPG in some cases whilst realising extra power.

No idea how this works on a petrol engine...
 
s0ck said:
On a diesel engine the Start Of Injection is, apparently, set before TDC which reduces power and economy but keeps emissions in check so there is a very real possibility of extra MPG in some cases whilst realising extra power.
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This is true, Our VW T4 Transporter 2.5TDi (102bhp) did 38mpg on a run, but now decat and remapped to 140bhp we are seeing 40+mpg.
 
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