Thread: Who has 285 tyres on there Defender?

Thats the spirit!

Originally Posted by Col.Coleman

My Interests are in long distance travel so I have Different requirements to putting around on the weekend. I use my vehicle to take me to the places I want to see then get out and walk, I don't feel the need to drive over everything I see. I drive on everything from bitumen to rocks, sand and mud.

I use mud tyres for offroad grip and toughness of construction. In these sizes the road noise is not noticable inside the cab with the air on, rolling resistance is much less than the wider ones in the aggressive treads(how's your fuel economy?), I pepper my car with less rocks on the gibber roads, am more precise with wheel placement in the tough stuff. On black soil roads and clay you want more wieght per square inch to dig down not float(up to a certain point, but after that the road is probably closed,flooded, you get fined for ripping it up or you are not getting through in anything anyway).

Legally I have no problems with main roads, my insurance company or police. Once you start modifying one thing where does it end? As a number of you have said you have reduced steering lock, tyres rub on this and that and you need to lift to gain back the clearence you had. This decreases your stability and at nearly 3.5ton loaded doing 110 in marbles that is something I don't want to give up for a fly**** more grip or clearance to get over something on the weekend that lets face it I don't really need to.

The widest tyre I prefer is 235/85r16. This size is the metric replacement for the 7.5016 but is actually a larger tyre(nearly 32inch and wider). Michelin don't import that in their muds so I use the 7.50. In the wheel ruts my tyres stay away from the rut sides where the rocks lay to stake your sidewalls. It is the jamming of big tyres into narrow ruts and the weight of the vehicle and drive forces snagging the sidewalls that tears them out. Stay away from it and there is less risk.

Taking into account the section v diameter equation the skinnies produce a longer rather than wider footprint which is better for floating your vehicle in sand. In a wheel track you are then traveling on the already compacted sand rather than constantly pushing through the soft stuff. The wider front section has to push through more sand creating more driveline stress and heat in the diff and gearbox/transfer case and uses alot more power hence more fuel. Not too great on the Canning. Of course there will allways be a situation where a little more float would be nice, but there is no 1 solution to everything or everyone would have the exact same tyre.

Contact patch gives grip, yes. But carcass construction, type, sidewall stiffness and tread compound give cornering ability and braking. Bigger isn't neccesarily better, just bigger.

Old cross plies were crap on the road but were very good off it. Bridgestone and Dunlop as well as a few others still make them prdominatly for light trucks and farm equipment that spend 100% of the time off road. I looked at some for my 4wd Canter.

Times change yes and modern 4wds are actually getting more car like and less capable, have less payload and towing ability. The tyres are wider and more like passenger car tyres than light truck.

That's why I drive a Defender. They got it pretty much right first up. Landrover have alot more money to test things than I do and the defenders still come out with skinnies on them. Good enough for me.

Nothing here is personal, just some of the reasons why I choose what I choose. If all the effort and mods in your opinion is worth the effort then go for it. Just bear in mind that there are so many different makes and models of everything out there and we all swear by different stuff, but we all seem to get to the same places no matter what we use. At the end of the day we all drive Landies.

Col - I used to think along the same lines as you (was running 235s on my IIA). Then I tried a set of 255/85s, and was impressed by the extra clearance they offered under the salisbury offroad. They tyres I wanted (MTRs) weren't available in 255, so I had to go to 285/75s. However I must say that they TRANSFORMED the handling and capability of the vehicle for the better - both on and off road. The landie felt more stable on road, and had better traction, and offroad the difference was almost unbelievable. They made a much bigger difference than fitting the locker did. Part of the difference is probably due to the compond, but the rest is the wider (and larger diameter) tyre.

When I bought my 110 county (also fitted with 235s), I tried my 285s on that landie as well. Same effect, handling, stability and traction on-road was so much better.

I recently did a 7000km trip across Australia (albeit 75% sealed roads) on my 285 MTRs. The 4x4 that was with us was fitted with 225s, and staked 2 tyres on the trip. I had no problems. For more remote trips I would probably use a more standard size though.

The ONLY downsides I have found are:
slight increase in road noise (but this is more dependant on tread pattern)
heavier and larger wheel
very slight increase in fuel consumption

Even tractors and offroad machinery are running wider tyres these days. But - there are plenty of people who switch to wider tyres that are SMALLER in diameter than the OE tyre, and this is a mistake IME. E.g. a 31x10.5x15 is smaller in diameter than a 235 or 7.50, and often performs worse than the skinny tyre.

Isuzurover - you need to clean your pm box a bit

Originally Posted by Aaron

Isuzurover - you need to clean your pm box a bit

Thanks! - PM's cleaned out.

what 110/120/130 rims (brand and size) do people use for 285/75 tyres? I thought these would require 16x8 rims. Is there such a rim for a landrover stud pattern?

I have 285/75/16s Silverstone MT117 Sports on the standard boost alloys which are 16x7s but actually measure 7.5" in width.They drone a bit but you get used to it, handling is slightly more vague then stock, but once again you cease to notice it after a while.Slight rubbing on standard height springs on the top of the shock tower at the front on full articulation and some slight scrubbing at the rear on tight fast corners.

i ran 285's on standard 16x7 disco steel rims, worked a treat, got the offest increased by 20mm od though. however you can buy 8's if you want procomp, kings, and a few other mobs make them, can evan get 10's if you really want...

I run 33/12.5/15 mud terrains on my 130, i have 8 inch rims with a plus one inch offset, they are a common aftermarket range rover offset, the turning circle is unaffected as the standard 7.50/16 is 32.7 inches and the extra width is out not in. Two inch lift under the spring perches.

hope this helps