JCL

As i recall when i was at college 1 gallon of derv had more callorific value than i gallon of petrol.

I stated that Gardner was an engine of the past, a Great British one only to state that diesels without turbos have a much higher torque to power ratio, the turbo only multiplies this both power and torque due to more air being forced into the cylinder so more fuel can be injected hence more power.

As for your argument regarding tax, RUBISH, the diesel X5 makes a much better drive than any petrol, it would probably be cheaper to fuel a petrol one here in the Uk at the moment petrol being 15p a litre cheaper than derv and Alister darling would only want another £120 a year in Road Fund over 12000 miles a year there would be something or nothing in the economics of running either, just the diesel and the sync turbo sd is a much better car and i sugest you try one that has at least 6000 miles on before making any judgements.