Come up with a list of high MPG cars and we're willing to bet that a car powered by a Chevrolet LS3, 6.2-liter, 425-horsepower V8 wouldn't be present.

However, just such a car has won one of the categories in the Fleet World MPG Marathon, bettering its quoted MPG figures by 50 percent.

The car in question is the Vauxhall VXR8, from General Motors' U.K branch. You might be more familiar with the car as the old 2010 Pontiac G8 GXP, and the car was originally developed by GM's Australian arm Holden as the Commodore HSV E3 GTS.

Equipped with an LS-series V8, performance is its strongest suit, and a gas-guzzling 17.5 MPG rating on the European combined cycle is testament to this.

In the hands of Top Gear Online editor Chris Mooney, the VXR8 managed 26.7mpg - a 53 percent improvement on the official ratings. The route took in 350 miles of driving including a mix of twisty country roads and freeway routes.

With strong torque available from very few revs it's perhaps no surprise that impressive figures can be achieved when careful technique is used, though we do wonder if it's a little soul-destroying driving such a car at only a fraction of its potential.

The overall champion of the event was the Smart ForTwo Cdi, a diesel model unavailable in the U.S. market. In the hands of eco-driving expert Mick Linford, it achieved over 82 MPG. We achieved 60 MPG in the Cdi when we drove it last year.

Just think - if every low MPG car achieved 50 percent better MPG than it does now, the fuel savings would be huge. It just goes to show - it's not always what you drive that matters - how you drive it is important too.


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