Tyre Height

I currently run General Grabber 235 85 16 on alloy rims. Does anyone know if I can go for a lower profile, like 70 or 75 without problems? What does the height do more than giving clearence? Thanks

Changes your speedo readings.

wammers said:

Changes your speedo readings.

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Aha, so it's best to stick to 85 then...

Well it'll change the speedo readings in the right direction ... ie you'll be going slightly slower than the speedo is telling you. You'll lose a bit of top speed too (1 revolution of the output shaft will now = slightly less distance/time)
http://www.tyresizecalculator.com/tyre-wheel-calculators/speedo-error-calculator

Don't know what sort of motoring you do with your Defender. I run the same tires on mine 235 x 85 x 16. A couple of years back I did a trip across Morocco in a group. One Defender was running a lower profile tire 265 x 75 x 16, I was surprised how many times he bottomed out compared to mine, plus I was very heavy loaded. I'm happy to stick with my current set up. It works well for me.

235/85/16 are the new equivilent of the 7.50x16's it was designed to run on, disco 1's had 235/75/16 which is quite a bit smaller,
the taller the tyre the faster you can cruse on the m/way but with a little less acceleration, i run 285/75/16 (just over 33" tall and 11" wide)
but stick on my 235/85's (32" tall, 9.5" wide) in the winter, theirs no advantage to going smaller, your speedo will read under as standard, mine was almost 6mph out against GPS on the standard 235's but with the 285's it almost reads true!
also having the bigger wheels gets rid of the need to swap for a disco trans box should you have thought about that option!

Apart from the speedo / acceleration issue, higher aspect ratio tyres in general give a more comfortable ride as the taller sidewall has more flexibility, but then again it can also make it wallow a bit more in the corners. Its all a bit of swings & roundabout thing

Kwakerman said:

Apart from the speedo / acceleration issue, higher aspect ratio tyres in general give a more comfortable ride as the taller sidewall has more flexibility, but then again it can also make it wallow a bit more in the corners. Its all a bit of swings & roundabout thing

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Yes, that's what I thought lower profiles would achieve, more sideways stability. But it doesn't seem to be worth it considering the cons listed above!

Disco 1s run 235/70/16 or 205/80/16 as stock. Yes they ride lower, I rarely find this a problem, I just pick my lines to try avoid defender ruts

I think dropping to a smaller tyre would make the arches look oversized, but disco sizes and a disco transfer box should keep your speedo happy.

Needless to say your insurance company would like to know about a change from stock sizes

I ran them on mine e for a while and I liked them. On the road it accelerated a lot better and actually felt like it handled better too.

Only swapped in the end for better ride height