Hope you are going to tell your insurance company when you have done it.

I quite agree. For a long time the smoke limit set the efective torque limit of diesels. Too many chipping companies still follow this rule. With high pressure injection, you can start hurting bearings and clutches before any visible smoke problems appear. I would lay off trying to bump up low end torque-no matter how tempting that might be. Torque is limited at low RPMs for a reason.There's probably not much harm in stretching the torque curve further up in the RPM range though, but leave peak torque alone.

Forget about "15% better economy" or simar spurious claims. You might get 5% or so if they programme out EGR. maybe another couple of per cent by advancing injection timing. All at a huge cost of Nox if anyone is bothered-but it won't crop up at MOT.

How can a man with a laptop better what a major manufacturer with ££££££££££'s of developement budget can. OK by putting more fuel in they can probably produce more pwer/torque but there is far more to making an engine work better than making it give better figures at full throttle on a dyno (if that is what they do).

If you want more power buy a different car.

it's a fair point, on my part I just want to know I am getting the best out of the car, on the manufacturers point they tune the car to meet all the regulations in every market that they sell it in, they do not optimise the performance, for example in UK tac is calculated according to C02 in other countries maybe according to BHP or Capacity, so the manufacturers "tune" will be a compromise to get the best results compliant with as many regs as possible.

Anotther view is that when a car is mass produced each individual car is not tuned by hand, time does not allow for that, and having a specalist hand tune it will get the best out of it.

I am not committed to doing anything, seeking the forums opinion - that's all

How can a man with a laptop better what a major manufacturer with ££££££££££'s of developement budget can. OK by putting more fuel in they can probably produce more pwer/torque but there is far more to making an engine work better than making it give better figures at full throttle on a dyno (if that is what they do).

If you want more power buy a different car.

If it were that simple, the manufacturer could just use a "man with a laptop" and save themselves £billions.

Cars sold in UK are optimised to Euro regulations which apply across the EU, including the UK. Cars sold in different emission regulation zones have different settings.

Edited by RT on 31/08/2012 at 18:50