ball park figure between 1 and 30
well you asked
smiles per gallon far more important than how much your aerodynamic brick is doin to the gallon
buy a mondeo diesal if you want economy
as per the smiles per gallon, i was under the impression they were constant![]()
Land Rover got 32MPG back in 1990 with the 200TDi without any computery or aerodyanmics (besides the slightly sloped windscreen!) and that's a big mahoosive 2.5 tractor engine in there too!