The new Range Rover will be revealed in September, but the rumour mill is already spinning at 7,000 rpm.

We think we know the new model will be a lot lighter (a good quarter of a tonne lighter) and more economical, but the big issue is how big it will be.

The current model has been a huge global success, but there has been some criticism of the amount of rear room. As the Range Rover has mutated into a super-prestige limousine (for example British royals are more likely to be spotted in a Range Rover than anything else), people have started to notice that the rear legroom is actually quite modest.

So now the big question is will the new model be made much longer, or will there be a Long Wheelbase version, possibly with a third row of seats for buyers with lots of kids (or possibly wives). Up to now, big families have been steered towards the Land Rover Discovery, but Range Rover may decide they cannot turn away buyers with £100,000 burning a hole in their pocket, and a need for seven seats.

The idea of Range Rover with MPV overtones sounds a bit worrying, but sister company Jaguar made a superb job of the long wheelbase XJ, so it might turn out well. Just don't mention the long wheelbase LSE version of the Mark One Range Rover, which demonstrates how not to do it.