What Car? Q&A - Will chipping invalidate my warranty?

I am thinking of purchasing a new Volkswagen Golf 140 TDI and am interested in the plug-in diesel tuning kits available. Can you advise me whether my warranty from VW will be affected by such a move?

Also, I have heard a rumour that VW may be bringing out a 175bhp version of its diesel Golf. Do you know anything of this, and when it might be?
John Stievenard

Your warranty will be invalidated by any power chips fitted to your car by anyone other than Volkswagen.

Often, the only difference between a lower-rated engine and a more powerful one can be the engine management chip. Although fitting one would therefore not necessarily put the engine under undue strain, Volkswagen is likely to refuse any warranty work if it discovers you've had one fitted.

A more powerful diesel Golf is on the way, however. The 2.0-litre develops 170bhp and should be with us around May. It will badged GT and is likely to cost at least £19,000.