Power : Weight

It's one of the golden rules of athletic performance: instead of just boosting your power, try reducing your weight at the same time. (It's why you never see any overweight marathon winners.) Ford have figured this out, after their Shelby GT500 pushed out plenty of power (540 horses, to be precise) from its supercharged 5.4-litre V8.



So that's the power side of the power-to-weight ratio sorted out. Now, to boost performance even further, they're leaving the power side alone and taking care of the weight side of things. They've replaced that previous engine with an aluminium version, reducing the car's overall weight by a hefty 54kg... making the car go even faster than before.

"It might not be as sexy as adding more horsepower or bigger brakes," reckons Shelby American founder Carroll Shelby, "but shaving pounds off of a car is the single smartest move you can make."