Porsche Cayenne Techart

What is it?

It’s a Porsche Cayenne diesel, having been given an aftermarket tweak to increase its power. Some say the standard Porsche Cayenne diesel isn't fast enough, and given that it has 237bhp to propel 2240kg, maybe that’s so.

Tech9, a UK motorsport specialist and distributor of products from German Porsche tuner Techart, offers a power upgrade. The Tech9 power kit (called Expedio) gives 290bhp at 3800rpm, with torque up from 405lb ft to 465 at 2650rpm. It drops the acceleration time from 8.3sec (to 62mph) to a claimed 6.9sec (to 60mph).

What’s it like?

The change is purely electronic. The Expedio box piggybacks off the engine's ECU rather than altering the original map, and doesn't increase turbo pressure either. Instead, it intercepts readings from ECU and tweaks the instructions for the fuelling and ignition before they reach the engine. The kit costs £2064, Tech9 offers a warranty and, if the system is removed, the settings return to standard Porsche ones.

The Tech9-tuned Cayenne’s power peak comes earlier in the rev range than the standard car and its torque peak arrives later, which compresses the zone in which the engine is at its strongest. But it hardly matters. The smooth-shifting, intelligent automatic gearbox (unaltered from the standard car) keeps the engine right in the heart of its bolstered mid-range, and as a result the tuned Cayenne feels quicker more often. Official fuel consumption remains unchanged, but I’d be surprised if the actual figures weren’t a bit worse.

And, um, you might have spotted some other changes? The visual ones? They're from Techart in Germany. Techart used to have a very decent relationship with Porsche – not dissimilar to Alpina's with BMW, I'm told – until Porsche brought its styling and personalisation brands in-house. But still Techart develops Porsche styling parts (and its own performance kits), which Tech9 also imports.

The test car's comprehensive list stretches to about £15k, including 21-inch alloys that don't do the ride any favours. Otherwise the handling is pure Cayenne - impressive for a car of its size. Now the performance isn't bad, either.

Should I buy one?

Let’s look at this in two parts.

First the styling kit, whose value can only really be discerned by the buyer. For what it’s worth, the new steering wheel feels good.

Then there’s the power upgrade, which takes none of the driveability away from the Cayenne and gives what will sometimes be welcome extra poke. So it’s all about your attitude to having a modified car, really. If you’re all for a spot of tweakery, then the Tech9 mods are worth having.