05 Feb 07
The octane rating of a fuel tells you how much the fuel can be compressed before it ignites, strictly due to compression. In a high-performance, high-compression engine, if the fuel ignites too soon - before the spark plug fires - this could result in engine 'knocking'. Thus high-performance cars usually need a high-octane fuel, such as super-unleaded petrol with a rating of at least 98 octane, expressed as 98 RON. UK petrol pumps dispense fuel from 95 to 102 RON.
The part of the car's body that protrudes further than the front or rear wheels. A car can have long overhangs but still not be very roomy for passengers - all the space is under the bonnet or in the boot - or have short overhangs and very little boot space, like many MPVs.
When the rear end of the car loses grip and it rotates in the direction of the steering, usually as a result of braking on bends or simply applying too much throttle. It often results in facing the wrong way up a road or a trip through a hedge, though it's part and parcel of racing on a track. Hooligans do it for fun. Easier to achieve in a rear-wheel-drive car, whether you want to or not. [See also: Lift-off oversteer, understeer]
