Fuel efficiency remapping

TherealMandM

It doesnt always work out more expensive either.
I use greenlight insurance for my impreza and it was cheaper to insure modified than it was standard through compare sites.

forgotmyname

More power can sometimes give you better MPG. But often with more power the driver uses that power for speed/acceleration instead of economy.

If your car cruises at 70mph @ 1800rpm increasing the torque at that level can improve the fuel consumption because the throttle position can be reduced.

Example in my old car 40mph in 4th gear used less fuel than 40mph in 5th gear. Even i had to think thats not right, we were always taught to change up a gear ASAP.
But in 5th gear the torque produced it not enough to pull the car along smoothly, so you need to add more throttle and more fuel, not to go faster but to maintain that speed. With mine the theottle position went from 9% in 4th to 18% in 5th.

With an increase in the amount of fuel being pushed into the engine to match.

mcpitman

For my 2p worth I have had a bespoke, rolling road tuned remap on a 2.0 diesel car.


This took power from 158bhp to 212bhp and torque from ~350 to 410.


This has increased my mpg (measured not the twaddle displayed on the dash), from 52mpg to 63mpg on an average tank.


Points to note;
I am currently doing ~30k miles a year at 90% motorway miles,
Generally drive conservatively and smoothly.
I have no dpf issues, however the end result map was turned down due to deemed limitation of gearbox strength.
The car has been like this for 90k miles and has not missed a beat or eaten a clutch/DPF (although now reaching 120k miles on the dash, this is a looming possibility)


Last point to note, to agree with what others have said.; if you hit the go pedal, this thing is an animal and can make you jump. It will guzzle fuel like no other if you do this too much. However if you drive as you did before or adjust to the "map" the efficiency gains for a £500 outlay is definitely worth it.

AdrianC

Gloomendoom wrote: »

I'm not sure what point you are trying to make.

Simple. That you're raising a lot of non-issues to try to justify something that makes no rational sense once you cut through the marketing guff.

The manufacturer's map may take ambient temperature (for example) into consideration but the values may conflict with the revised parameters of the remap.

Sounds like a fairly half-done job of a remap, then.

motorguy

AdrianC wrote: »

Simple. That you're raising a lot of non-issues to try to justify something that makes no rational sense once you cut through the marketing guff.



Sounds like a fairly half-done job of a remap, then.

So basically you're saying remaps dont work, when people who have actual experience of them done to their cars say they do?

I've only ever remapped for more power, however i have noticed as an aside the car - with brim to brim fuel fills - is marginally more economical.

Now i am sure you will now produce some other colourful but irrelevant graph to show your theory is right but reality is somewhat different.....

Gloomendoom

AdrianC wrote: »

Simple. That you're raising a lot of non-issues to try to justify something that makes no rational sense once you cut through the marketing guff.

What specifically, remapping for economy, or remapping in general?

AdrianC

motorguy wrote: »

So basically you're saying remaps dont work, when people who have actual experience of them done to their cars say they do?

It's called confirmation bias.

Gloomendoom

AdrianC wrote: »

It's called confirmation bias.

On mine it was called 8 seconds 0-60 to 6 seconds 0-60.

forgotmyname

If you can time your 0 - 60 to 6 seconds, you need to go back and get that remap sorted.

Mines so fast it pushes me back in the seat so far that i cannot reach the pedals, laws of physics actuated speed control

Dont get any ideas i just applied for the patent on that

mcpitman, if your using it to gain efficiency then the extra power and torque wont hurt the gearbox. Its when you take advantage of that power especially in the lower gears. Sticking 400Nm of torque through a gearbox designed for 300Nm and flooring the throttle in each gear will be the killer.

Or letting the revs drop too low and flooring it instead of changing down.

But has anyone thats done a remap for economy or efficiency, not actually used that extra power, and mroe than once?

I know with mine its fun when the midrange overboost kicks in, reminds me of SAAB turbo's. Nothing nothing nothing whoosh... Bl**dy Hell... Brake...Speed limit.

motorguy

AdrianC wrote: »

It's called confirmation bias.

No, its called "actual experience". You should try basing your views on it.

And saying as you like graphs to prove your point, heres one to summarise it for you.