Thread: Tyres 255/85 v 285/75

I have, but on a Discovery2, not a Defender.

I found the 255/85 was no where near as stable as the 285/75 laterally.

What this meant is that on the road the 255 moved around laterally a lot more than the 285 and because of this you have to run higher pressures in them to regain that stability. Even unloaded the 255 had to be at least 36psi and you couldn't really run them any lower, even unladed without losing stability. Same offroad, where when you get side angle or side forces they were prone to roll under which can be pretty disconcerting, especially considering it is probably already an uncomfortable situation. This was with 255 AT and MT, the MT's a fraction better than the ATs. The 285's dont do any of that weird stuff and they're as stable as a rock on and offroad. Offroad I run them down to about 12psi and they're fine. On road I run them as low as 28 on the front, but they really need about 30psi minimum otherwise they push too much. When towing then they are all better with more pressure, but I think that has more to do with the Disco2's inherent dynamics.

Offroad I tend to think the 285 is a better tyre, its just far more predicatable and stable. Puncture wise I've never done a sidewall in either of them. Onroad likewise I think it is more stable and predicatable also but I think the 285 uses a bit more fuel. I think it has more to do with the tread pattern design, but never the less I do think they use a bit more anyway. The 285 has a significantly wider range of tyres you can choose from in comparison to the 255 and they're easy to get.

Alternatively, get a second hand for the spare, from a second hand tyre importer.

Hi Simon,
That confirms what I thought might be the case.

Ian,
I can get hold of a 285/75 for a spare, I don't hold much hope for finding a S/H 255/85 that is any better than the couple I have.

Tony

Originally Posted by TonyC

Hi Simon,
That confirms what I thought might be the case.

Ian,
I can get hold of a 285/75 for a spare, I don't hold much hope for finding a S/H 255/85 that is any better than the couple I have.

Tony

Interesting... I'm keen to try the 255/85 as up until now I've been running the std 235/85. The comments regarding stability doesn't really apply in my situation as I would be going from a 235 to a 255 so if anything I would have better stability (?). I think handling wise there is a bit of difference between a Defender and Disco as well.
As u have mentioned, the availability of 255 is the issue but should the case arise that I needed another 255 while touring and I couldn't get one, then my thinking was if I had a rim as least that could take either a 255 or 285, then I could just simply buy a 285 in an emergency to get me through... I could if I was desperate even possibly use a 225/95/16 - (Rim width might be the issue here though) off a Cruiser as all these tyre sizes are pretty much the same diameter

thoughts...?

Originally Posted by Robmacca

. I think handling wise there is a bit of difference between a Defender and Disco as well.

Considerably, unless we're talking a 90. 110/130 dynamic differences are obvious, and that's before loading, which of course only increases the differences.

Should have had a better look at yours, Rob. I just assumed they were bigger.

Originally Posted by Robmacca

Interesting... I'm keen to try the 255/85 as up until now I've been running the std 235/85. The comments regarding stability doesn't really apply in my situation as I would be going from a 235 to a 255 so if anything I would have better stability (?). I think handling wise there is a bit of difference between a Defender and Disco as well.
As u have mentioned, the availability of 255 is the issue but should the case arise that I needed another 255 while touring and I couldn't get one, then my thinking was if I had a rim as least that could take either a 255 or 285, then I could just simply buy a 285 in an emergency to get me through... I could if I was desperate even possibly use a 225/95/16 - (Rim width might be the issue here though) off a Cruiser as all these tyre sizes are pretty much the same diameter

thoughts...?

Maybe we should plan a Vic High Country trip, you can try my 255/85s.

I wouldn't hesitate to fit 285/75 or a 225/95 to a 6.5 or 7 inch rim to get out of a pinch, chances are it will never see the road.

Tony

Originally Posted by TonyC

Maybe we should plan a Vic High Country trip, you can try my 255/85s.

I wouldn't hesitate to fit 285/75 or a 225/95 to a 6.5 or 7 inch rim to get out of a pinch, chances are it will never see the road.

Tony

Bugger... Wish I had read this earlier as I was down there in April'24 for 3weeks exploring the VHC....