Tyres again... 255/85R16 on a defender 90?

[Toxic_Avenger]

I'm after info regarding tyre sizing for my 2012 90.Would love to hear from those who have 'been there / done that'. I'm looking ton fit a 255/85/R16 (33") tyre to the 90.

Details regarding my vehicle below:

1. Stock height (no lift), original suspension with 35,000km on the ODO.
2. Bullbar, winch and rear bar- contributes to extra weight, suspension sag
3. Dual finish alloys- 16"x7" IIRC (unsure of offset, but +35 rings a bell?)
4. I want a larger diameter M/T tyre to replace an aging and very chipped set of 235/85R16 Goodyear wrangler MT's that have been on the vehicle since new

The factory 235/85R16 work well, but I'm often left scrubbing the diff in a few of the ruts and tracks I drive, moreso at lower tyre pressures.
I'm not in a position to lift the vehicle yet, but am looking for something that is a little bigger.
Not sure whether to lean towards a skinny tyre or a fat tyre... my thoughts are lean towards the narrow. Not sure about the trade off of tyre diameter vs tread width in relation to accelleration / handling, but keen to know more.

From what I read in countless hours of searching is that the 90's have a different (smaller) rear spring diameter and top bracket, making more room for wider tyres (at the same rim offset) than the 110's or 130's. I've heard whisperings of some potential loss of steering lock at a 33" tyre size, but not sure if the limiting factor is tyre height or tyre width...


Keen on the BFG Mud Terrain T/A KM2's in 255/85/R16. ie a 33"x 10" on a dual finish alloy rim.
Has this combo been done before? Any feedback?

[cuppabillytea]

I'm keeping an eye on this Mitch. I'll be up for new ones soon myself. So far I''m leaning toward standard Conti ATs. They've served well so far. However I can see why you'd be looking for a bit more clearance.
The size you're thinking of is going to make it vague in the tar though.

[Vern]

Not to be rude, but there is so much info on that Tyre size on here! Have you tried using the search function?

[Toxic_Avenger]

I like the idea of a mud tyre, they might be a bit more noisy and not as good on road as an AT/HT, but on the other hand, my wrangler's have never let me down when I've needed them. Except for that time I'd sunk to the diffs in slimey mud- hence the hope for larger diameter rubber!

Can anyone explain what the biggest contributing factor is with handling changes with a tyre? Does larger width cause it to be vague, or is it the diameter, or just the sheer extra rubber and weight have to be spun by the engine that makes the vehicle sluggish?
One thing I've read is that 255/85/R16 will bring the speedo up to pretty much accurate

On width... wouldn't larger contact patch would be better for low traction conditions off road, but likewise the narrower tyre puts more concentrated pressure on the ground like for mud snow etc?

[Toxic_Avenger]

Yes I've searched, and a clear answer for my example was not found. I actually forgot to add my bibliography to my first post- sorry

The good oil has lots of broken links, and info that is not specific to the 90. Most posts are from 2005! Most posts don't even discern between the model on which said tyres fit.

My line of questioning is particularly focused at a stock suspension puma 90 which is carrying a bit of extra weight. This vehicle has the dual finish alloy wheels (different offset to the steelies), and I particularly want a larger diameter wheel for predominantly offroad use- a MT tyre.

I'd consult the opinions of a professional, but out of the 2 places I called yesterday, one of them said 'there's no such thing as a 255/85R16' . It's a larger investment that will be with me for many years, so want to get it right.

[cuppabillytea]

Hi Mitch. The reason I think it would be a little more vague is the little extra hight you would be putting on your side walls. I imagine that the shorter wheel base of the 90 would make it quicker steering which in turn would accentuate any vagueness.
I was toying with the idea of going wider but not necessarily higher. Thanks for being my Guinea Pig.

[D90 orkney]

After doing similar research I was under the assumption that you can go 265/75/16 with no rubbing and no lift.

I have 285/75/16 with 30mm spacers on sawtooth rims and 2 inch lift. I plan to take spacers off and go -25 with steel rims soon. I feel the extra width is great off road keeping rock walls and the such away from my panels. Also my turning circle improved with the offset

[D90 orkney]

Give Andrew at LRA a call. They are normally very helpful and know there stuff

[Toxic_Avenger]

After doing similar research I was under the assumption that you can go 265/75/16 with no rubbing and no lift.

I have 285/75/16 with 30mm spacers on sawtooth rims and 2 inch lift. I plan to take spacers off and go -25 with steel rims soon. I feel the extra width is great off road keeping rock walls and the such away from my panels. Also my turning circle improved with the offset

Stands to reason- the stock rubber is 235/85/R16 - 31.7".
265/75/R16 is a 31.6" (but 30mm wider than stock- 15mm wider each side of the rim bead).
So you are saying that an additional width increase of 30mm is about the limit on a 90 before you start running into clearance issues on the sawtooth alloys?

I'm not really keen on spacers. I'd more likely than not run stock sized rubber before going the spacer route.

Does anyone have any feedback of tyre clearance within the wheel well running 33's? Is the general idea (on a 90) that tyre width is a limiting factor or tyre height?

[D90 orkney]

Stands to reason- the stock rubber is 235/85/R16 - 31.7".
265/75/R16 is a 31.6" (but 30mm wider than stock- 15mm wider each side of the rim bead).
So you are saying that an additional width increase of 30mm is about the limit on a 90 before you start running into clearance issues on the sawtooth alloys?

I'm not really keen on spacers. I'd more likely than not run stock sized rubber before going the spacer route.

Does anyone have any feedback of tyre clearance within the wheel well running 33's? Is the general idea (on a 90) that tyre width is a limiting factor or tyre height?

From my understanding, I wanted 285 so to not hit bump stops and clear everything I read that 30mm spacers were needed or -25 offset rims. I'm not keen on the spacers either but it was a means to an end at the time.

I also understand that 265 was the most you could run on a 90 stock. I don't think 75 or 85 will make much of a difference