wats the max weight you can pull with a v8 when towing ie a snow rescue.?

Up hill or down?

Up...........

Did 18 tonne up hill in snow in reverse.

There's no set answer to this question as (any) vehicle's ability to pull under these circumstances is always going to be way beyond it's stated towing capacity. As a guide I know of occasions many years ago (when we had real winters) of standard series LR's pulling 32ton artics & I've no doubt many forum users will chip in with tales of their own achievements! One point worth mentioning though is that using your own vehicle to pull in reverse is not a good idea as it's arguable the weakest gear in the 'box. At one time LR used to publish figures relating to 'draw-bar pull' but I don't think it's considered relative these days & seems to have been replaced with on-road performance data!

pulled a artic truck up a hill last christmas to clear it out of way so traffic could get past. was a struggle but the limited slip diffs helped a great deal to keep traction down.