Disco 2 255/65 or 255/70 Pros and Cons?

Hi folks.

I managed to get a set of rims with 255/65 r16 tires. Wider than my 235/70 r16 tires and rims and I like the better handling the wider tire seems to offer. I also like the added ride height. The tires are half worn and it still feels taller with these on!

Now I have read that a 255/70 does not cause rubbing and looks better. Is this true? I like the idea of taller tires for more cushioning. I live in pothole city. I also figure with a larger rolling radius my motorway miles to work will get better fuel economy. The sticky tire guide seems to be for Disco 1 tires so am not sure of the total diameter difference? As the other issue is I must be able to fit under the barrier at the local tip. My Disco has stock roof bars which also impede clearance if I were to go too high.

Any info to sway my decision is appreciated.

You may not actually get improved fuel consumption from the taller tyres because unless you've got surplus torque at motorway speeds, you may end changing down on hills etc.
The taller tyres will certainly give you a better ride, but the other compromise will be increased turning circle as the tyres will foul the radius arms sooner.

Foul the radius arms? That does not sound fun? How would they do that? The current ones don't as far as I can tell and the extra height does not add extra width...or does it?

One of the issues completely neglected by everybody when it comes to tyres is the ABS system, up to 5% difference it's still relatively safe so not huge problem for 270/65/16 cos it's 3.5% bigger but the deceleration threshold and braking distance are increased approx with the same percentage like the difference between standard and bigger tyres, That's about your and other's safety on road, i have no problem with off road driving. The whole complicated system was calibrated from factoy for standard tyres... with bigger than standard tyres the ABS system(+TC, EBD, HDC) will not do what it was conceived to, depending on each situation it's possible to not kick in when it should or to kick in and you'll just feel the pedal pulsing under your feet and watching how the vehicle just rolls over... the explanation is long, complicated and full of technical elements extracted from original WABCO documents(e.g corresponding trigger signal, stable braking range, refference speed of ECU, coefficients of friction, modified individual control, etc) but i made comparative tests with my car and others with more kind of different than standard tyres and some results were really scary....only one live example: with my car standard 255/65/16 Dunlop Grandtrek AT3 tyres and 265/70/16 BFG T/A KO2 so only 5.4% difference on the same muddy(but solid) ground from same speed(40km/h) the halt distance was increased with close to 2 meters ... all those elements named above were calibrated for standard dimension tyres and pressures and any difference mixes up the whole algorithm...and it's a complicated one, i've spent hours with calculatioins and graphic simulations too and my conclusion is that anything above 5% difference becomes a real danger ... i'm just warning everybody to know well that and addapt the driving style accordingly ... this warning is mainly for on-road driving for your own and other's safety ... with big tyres there is the risk to push the brake pedal, to feel a pulsation, snuggle the steering wheel and watch with serenity how the vehicle just goes and doesnt stop

another worrying element is that with those tyres under hard acceleration on road the EGT was on the red zone not once with the bigger tyres, up to 250*C difference(from 650 to 900*C) so the ECM's addaptive strategy is mixed up as well cos the VSS(vehicle speed signal) which is part of the management is out of the table cos the SLABS was calibrated for std dimension tyres

IN a nutshell: USE STANDARD OR AS CLOSE AS POSSIBLE TO STANDARD DIMENSION TYRES

The D2's ABS system is very sensitive for any ''missbalance'', just a "flavour", one out of 12 similar pages which explains the system .... and i say again: it was calibrated to work well with standard dimension/pressure tyres

The best ride i've experienced ever was with 255/65/16 tyres ... and i tested a few variants believe me

Then ONLY gain of bigger tyres is the ground clearance but the side effects on the engine management and ABS are making the whole thing worst IMO

Thanks Sierraferry. I think you have convinced me to stay with 255/65 r16. Much appreciated.

I changed to 255/70/16 a few years ago. It is ok for me but I totally agree with Sierraferry. Braking is a bit less good but there are possibly better break pads.
I change back to standard as soon as these at tyres are worn.

but they look the right size on a standard disco!

Ahaggar said:

I changed to 255/70/16 a few years ago. It is ok for me but I totally agree with Sierraferry. Braking is a bit less good but there are possibly better break pads.
I change back to standard as soon as these at tyres are worn.

but they look the right size on a standard disco!

Click to expand...

the quality of brake pads is not a factor when it comes to ABS cos the system will addapt pressure to achieve the preset deceleration if you see what i mean...the brake pads are more important on non-ABS vehicles

have you looked at 245/70/16, not a lot of difference to the 255/65/16, just a bit more tyre wall

try this,

https://www.tacomaworld.com/tirecalc?tires=255-65r16-245-70r16

I'll have a nosy. Thanks.

discodrivercumbria said:

have you looked at 245/70/16, not a lot of difference to the 255/65/16, just a bit more tyre wall

try this,

https://www.tacomaworld.com/tirecalc?tires=255-65r16-245-70r16

Click to expand...

I run 245/70 R16's on mine and don't really notice much difference in performance compared to the standard 235/70 R16 (2001 D2).
The actual difference in radius between a 245/70 R16 and a 255/65 R16 is around 5mm (depending on tyre manufacturer and their products actual dimensions).

For those not in the know, 245 = 245mm tyre width (or thereabouts) at the tyres widest point, 70 = 70% of the tyres width, R = Radial, 16 = rim diameter.

Got 245/75-16's (Kuhmo mt's) on my D1. Best compromise. Look right without being overtyred,

I have put on a set of 245/75R16 Maxxis mudders and they seem to not have hampered the performance and runs just fine and dandy as my Disco is now my daily driver..... i was wondering though as i am considering putting on some larger rubber and taking into consideration my Disco is an automatic and uses a torque converter, with larger diameter tires will this have an adverse affect on my gearing in any way??

Thanks in advance