In reply to dunc56:
> (In reply to John_Hat) And how many of those cars were permanent 4wd cars ? With a lot of non off-road specific cars the 4wd is only engaged when the front wheels spin. So for the rest of the time you carry round 100kg of useless 4WD driveshafts and associated stuff. Well worth it.
All permanent 4WD, with a varying percentage going to each wheel depending on grip.
If I'm getting 65mpg (ok, in town 45-55mpg) and have low carbon emissions (which I have), then why is the weight of the car relevant when my car is demonstrably more efficient than most of the other cars on the road?
> And when was the last time you were driving on a road when the limit of adhesion of modern tyres was reached ? (so the 4wd kicked in) hmmmmmm
Erm. All the time. In fact pretty much any wet road.
I had a 2wd car for a bit (Mondeo) and was quite alarmed at the massive difference the 2WD made. It's not just adhesion, its just that when you are, say, going around a roundabout, the front wheels have to do both steering and traction, and in the wet they don't do both at the same time well.
I appreciate that to many 2WD owners there is only one reason for 4WD and that is muddy fields. I was stunned at the **massive** difference it made to the way the 4WD cars reacted in the wet or on any poor surface. It isn't just traction, its balance and security and stability.
>
> Also on a corner a 4wd car is likely to understeer anyway if the limit of adhexsion is reached - which is hardly safe is it ?
I don't go anywhere near the limit of adhesion on corners, thanks! Cornering near the limit is something I only ever do by accident. However all the FWD cars I have driven understeered (I was more of a loon in them days) **grin**.