What Car? Q&A - What makes a tow car?

Q: When looking at the performance figures for a car, which is the most relevant for towing? I don’t know if BHP or pulling-power (torque in lb ft), is the best indication of how suitable a car is to tow a caravan.
Steve Stuart

A: Generally speaking pulling power, or torque, is the most useful when it comes to towing. Different types of cars have different characteristics, and a high horse power car may not be a suitable towing vehicle, as it doesn’t produce enough torque.

Not only is the amount of pulling power a car generates important, but also the way it delivers the torque. Engines that deliver their maximum power at high revs, or in a narrow range of engine revs, also make poor towing vehicles.

Good towing vehicles generate torque low down and deliver a consistent pulling power throughout the rev range. Diesel engines generally perform well, because they have this characteristic without needing to be too thirsty. Large petrol engines, such as a 4.0-litre V8, can tow well, but fuel consumption is far higher.