A diesel automatic Ford Mondeo is almost as big as a Ford Falcon but the $37,990 Mondeo gets 7.3L/100km compared with the $39,990 Falcon G6 automatic's 10.5L/100km. So although diesel is about $1.70 a litre and petrol is $1.50, at 15,000km a year, the Mondeo will still save you $700 each year.

The Mondeo emits 197g/km CO2 and the Falcon is 252g/km CO2.