CDTi Remap questions...

[LowFlyingBus]

Originally Posted by Ray L

I had a re-map on my cdti 130. Little difference noticed on actual performance but probably a consistent 10% improvement on mpg.

Interesting. Do you know how it improves MPG? Timing changes or something?

[another_clean_sheet]

Originally Posted by LowFlyingBus

Interesting. Do you know how it improves MPG? Timing changes or something?

Could be because the mid range torque is significantly improved. Whether it produces 160bhp or not, it is worth doing.

[LowFlyingBus]

Originally Posted by another_clean_sheet

Could be because the mid range torque is significantly improved. Whether it produces 160bhp or not, it is worth doing.

Mm. So you're revving it less, at the end of the day. That would make sense.

[Rogue]

Originally Posted by another_clean_sheet

Could be because the mid range torque is significantly improved. Whether it produces 160bhp or not, it is worth doing.

I would agree with this.. I did a run up to Manchester and back a year or so back and did a brim to brim check for consumption and it returned 57.1 mpg which i was very happy with.
https://www.the75andztclub.co.uk/for...d.php?t=269044

[Jamiewelch]

Originally Posted by another_clean_sheet

Could be because the mid range torque is significantly improved. Whether it produces 160bhp or not, it is worth doing.

It isn't (compared to a stock 131ps). I'll find a dyno printout showing the map vs a stock 131ps tune.

Also, just so people know with regards to MPG, once remapped you can never trust the MPG readout on the car, it uses the stock injector timings and duration to calculate the MPG, once these have been altered on the ECU the IPK isn't aware and miscalculates.

[Rogue]

Originally Posted by Jamiewelch

Also, just so people know with regards to MPG, once remapped you can never trust the MPG readout on the car, it uses the stock injector timings and duration to calculate the MPG, once these have been altered on the ECU the IPK isn't aware and miscalculates.

So how would that explain the results from a brim to brim test as explained in my post?

[Jamiewelch]

Originally Posted by Rogue

So how would that explain the results from a brim to brim test as explained in my post?

Going on a drive isn’t scientific. Engine temperature, gear changes, external temperature, fuel, fuel temperature, air quality, air temperature at intake, throttle usage, engine adaptations will have been reset during map, injectors could decide to perform better one day, higher voltage could result in higher fuel pressure etc. There is all sorts that effects mpg. Do the same trip multiple times and you’ll get different readings.

[another_clean_sheet]

Originally Posted by Jamiewelch

Going on a drive isn’t scientific. Engine temperature, gear changes, external temperature, fuel, fuel temperature, air quality, air temperature at intake, throttle usage, engine adaptations will have been reset during map, injectors could decide to perform better one day, higher voltage could result in higher fuel pressure etc. There is all sorts that effects mpg. Do the same trip multiple times and you’ll get different readings.

You mean that the figure could be even higher!!

[Rogue]

Originally Posted by Jamiewelch

Going on a drive isn’t scientific. Engine temperature, gear changes, external temperature, fuel, fuel temperature, air quality, air temperature at intake, throttle usage, engine adaptations will have been reset during map, injectors could decide to perform better one day, higher voltage could result in higher fuel pressure etc. There is all sorts that effects mpg. Do the same trip multiple times and you’ll get different readings.

A 412 mile "drive" is a reasonable sample and clearly every journey would produce different figures due more to traffic than most other variables however i did not claim that it was anything more than a snapshot showing the map had certainly not reduced MPG on this run.

[Jamiewelch]

Originally Posted by Rogue

A 412 mile "drive" is a reasonable sample and clearly every journey would produce different figures due more to traffic than most other variables however i did not claim that it was anything more than a snapshot showing the map had certainly not reduced MPG on this run.

Oh you won’t lose MPG during general driving. A remap won’t ever give more MPG unless you have the car mapped for less power. More power = more fuel, it’s as simple as that. Yes the power curve can be shifted so you get more power low down, but that means you’re using more fuel lower down in the revs than you were before.