Sir -- Motormouth's case on behalf of urban 4x4s is deeply flawed in every respect (Oxford Mail, July 7).

He may own a 4x4 that is more economical than some saloons, but he conveniently forgets that the extra weight, brick-like aerodynamics, excessive rolling resistance from oversize tyres and inefficient drive trains mean that any 4x4 will always underperform and be less economical than a road car with a comparable engine.

He claims that 4x4s are less prone to skidding. That is because oversize tyres restrict performance and have a large footprint. They would skid if you could get them to go fast enough.

Anyone with a tentative grip on the laws of physics will tell you that the higher you raise a vehicle, the less stable it is when cornering, so if the highest cars on the road are stable, it is due to the engineering, not the ego-boosting height.

4x4s are not designed to handle well -- and they don't.

Motormouth says that depreciation is less but, as an owner, he would say that, wouldn't he?

I challenge him to prove his statement by getting someone to buy his 4x4 for the price he believes it is worth.

Proper 4x4s are built to cope with harsh terrains, including deep water, steep slopes, poor road surfaces, excessive heat and/or cold and anything else that remote situations can throw at them.

To say that you need one of these beasts to drive over speed humps is pathetic.

The robust construction of a 4x4 does make them safe, but from whom do you need to be safe?

The answer is overweight, oversized vehicles being driven at speed over traffic calming measures designed to improve safety.

Face it, 4x4s are the problem, not the answer.

TIM HUNT

Compton Drive

Abingdon