New Goodrich Tyres please help me with size?

[Tarquers]

got you , well im not lowering at all , the purpose is to go gently off road down the odd green lane etc being mindful of ground clearance (i am lucky to own the new defender which i can use if its that bad lol) but main purpose is use for me doing wildlife photography so the odd grassy field etc nothing too dramatic but having the confidence i can go somewhere where the normal road tyres may struggle a bit , but at same time will be doing trips to france and although i know i lose mpg but i cant have spare wheel cos of my 18 inch wheels so i thought the great tread may help with avoiding punctures too?

you can still fit a spare with 18 inch wheels, been plenty of discussion on here but they do fit. I know this from first hand experience, albeit I swapped 18s for 17s. Lugging a heavy BFG out from under the van to swap in the rain at night is not on my list of fun things to do!

Have you thought about the effect of BFGs on your drive train? they are really heavy tyres and the greater rotational mass will wear out things like CVs, brakes and driveline components, plus a bigger tyre means slower acceleration, slower stopping, not to mention the very poor comparative performance in the wet for stopping. after 50k kms also be prepared for a tyre that becomes very noisy.

When it comes to ground clearance, you really are not going to get much difference in terms of clearance. Yes the wheels are bigger, but you only get half that height difference increase. only way to really improve ground clearance is to lift the suspension which can create more driveline issues.

When you weigh up all the pros and cons, I think you will find many more cons than pros, and there are much better standard size options available. A narrow tyre is more likely to find traction at the correct pressure than the 235 or 255 options in the muddy field scenario, along with the standard diameter reducing a loss of power and therefore giving you more control.

On a final note, they do look really good on a van which seems to be the reason why the majority of people put them on!