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Diesel tuning box chip

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Has anybody fitted one of these diesel tuning chips to their diesel S Type?

They are sold on E-bay for around £80.

The sellers claim an increase in bhp (from 206 to 245) plus increase of around 20% in MPG.

The feedback from buyers (for various diesel cars) looks great, seems a bit too good to be true!


Any ideas or experience anybody!!




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Keith ,

            Really don't know much about them , but they do seem to get good reviews form various people , whilst others where indifferent , couldn't find any negative feedback about them so it might be worth a spin.


This review seems to be the most balanced:



" Some chips or remaps just allow for more fuelling and adjust the
fuel/air mixture thresholds to increase the power. They'll often over
fuel the car and the result is lots of smoke - common problem with bolt
on power modules or smoke boxes as they are sometimes called. They'll
claim better mpg because you can access more power/torque and don't need
to rev the car so much and can hold a higher gear longer. They often
don't update the car's logging data so the computer info on mpg doesn't
see the extra fuel being burned so the only real test is to measure at
the pumps brim to brim. 

The more developed remaps adjust and recalibrate a much wider range
of ECU values and can have a more positive effect on the economy as well
as more power and smoother power delivery.

Four of my last five cars, 3 of them diesels have been remapped and
all have been successful in that the cars power has increased and I had
no problems with anything failing. Only one of them turned out to
genuinely improve economy whereas the others it dropped but that was
probably down to using the extra power. Worth checking out other
people's views of the chip you're considering on owner forums and see
what their experiences of mpg and reliability are."



Do you have a tame mechanic you could take advice from?





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  • 2 weeks later...

The 'bolt-on' tuning boxes fool the ecu into believing the fuel pressure is low and simply put more fuel in. On turbo-charged cars that's not complemented by an measured increase in air from the turbo pressure being increased as the ECU thinks everything is as it should be. As a result, you'll likely get a cloud of black diesel smoke in your rear view, a clogged DPF if you have one, a catalytic converter full of soot and a clogged EGR valve. The box may only cost £70 but the resulting (damage is the wrong word) will cost you much more in the long rung.


I will be using these in the very near future to remap my 2.2 X-Type - www.celtictuning.co.uk

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