Arias Pistons 12.5:1 Compression 82mm Bore Honda B-series on 2040-parts.com

Koenigsegg's craziest supercar yet debuts at Geneva

Here's what you need to know about the Koenigsegg One:1. It weighs 1,360 kilograms; it produces 1,360 hp. One horsepower per kilogram, which is why mad scientist Christian Von Koenigsegg is absolutely justified in bragging about it: it's the world's first "mega car," he said.

Do Winter Tyres REALLY work? Oh, yes, say Volvo (+ video)

Volvo prove how effective Winter Tyres are in the Snowdome For some reason, the debate on fitting winter tyres in the UK continues to be a debate, even when those who’ve actually used a car fitted with winter tyres swear by them (an argument not helped by previous government advice). So Volvo – safety conscious as ever – decided to prove the point by taking the very good Volvo V40 off to the Snowdome indoor ski slope in Tamworth to see exactly what difference a set of winter tyres makes to the grip available in a regular, FWD, family Volvo. And the results should make every car owner go out and fit winter tyres.

Enter the Autoweek Big Game Giveaway!

What better way to spend some holiday free time than flat-out on the virtual limit. We're giving away copies of F1 2011 for PlayStation 3 and Xbox 360, Forza Motorsport 4 for Xbox and Dirt 3 for both systems. We also have an Xbox wireless steering wheel bundled with Forza 4, and the grand prize is a Dirt 3-branded Playseat, a Kinect special-edition Xbox 360 250 GB and copies of F1 2011 and Dirt 3.