Hi all, I too have been recommended to go for 275/35/20 for my set up. I've got 4 original Range Rover 'style 511' ET53 8.5J alloys which are the dog-leg double 5- spokers. I bought them 2 years ago while they were available as I knew I'd get a van at some stage
The reasoning / theory I was given was the 275 width is to maintain some tyre wall protection of the rim. I asked about 245's but the 245's wouldn't be physically wide enough to match a 9'' rim (although mine are 8.5J). As such you would get tyre 'pull out' at the rim and I personally would avoid that look from an aesthetics point of view. The 35 profile as already stated is the rolling circumference to maintain a reasonable speedo reading.
Now I'm not trying to teach you guys to suck eggs as we all have our own ideas and choices of what we like - This is also my own learning curve. That said, you do see some vans which have been severely over-wheeled and /or over tyre'd and they really stick out (no pun intended). I see this thread is over 2 yrs old and it seemed daft to start another of the same theme.
I haven't had my wheels shod yet as 1) not sure which tyre make to go for and 2) not had chance to try them on the van with the spigot rings etc to make sure they fit nicely against the hubs and callipers and 3) I'm thinking of fitting H&R 40mm coils first with the original suspension as my van is only a year old. I've never seen a van with RR style 511's on but I'm hoping they'll look nice.
So all this dribble is a lead up to ask you guys to show us some nice wheel arch shots tagged with the wheel name, diameter and tyre / size info.