Hi Mikey,
I'd posted this reply on the Touring and Tenting forum.
Chipping the Mercedes 270 CDI engine:
There is some benefit to chipping this Diesel engine if you are looking for out-and-out bhp, but not such a benefit for towing when torque is all important.
The Brabus (approved Mercedes tuning company) chip increases bhp from 183 (or 177) to 220, and increases torque from 410 (or 400) to 440 NM torque. The plain text is the last phase of the 270 engine, in brackets is the previous model - but only if you have the automatic gearbox.
By increasing fuelling to the engine, 20% more bhp can be released - but only 10% more torque.
So as it comes out of the factory, it's pretty much sorted as regards torque - so unless you really feel you need it, don't do it - 410 NM of torque is a whole load of torque.
New:
It is apparent that outside of the "official" upgrades some companies will offer torque upgrades of almost an extra 100 NM - this is outside the (long term reliability) design limits of the Mercedes 5G Tronic automatic gearbox.
Robert