34 inch tyres

[adrian]

Guys

as you may be aware i eventually got round to fitting my 2inch lift kit, descided not to go to 3 to try and keep some of the road handling, as it is my everyday driver.

the next task is the incar adjuster, and raiser breathers, see other threads.

however this now brings me onto the next task, which is tyres!

i have the standard size (245-70/16) fitted at the moment (on 1996 bighorn/trooper)

my friend suggested 255-85/16 which is about 33.3inch tyre, which sounds ok, but it would be nice if i could break the 34 inch barrier.

are there any body mods that i can do to get 34inch rubber on the thing?

or am i best sticking with the 33s??

hope you can help

adrian

[geeves]

Dont know anyone running bigger than 33 inch on bighorns unless they have gone whole hog and fitted solid front axle etc. You will also have gearing issues with bigger tyres. As it is a lot of people have found that the 3.1 diesel changes from fairly ecconomical and perky to a thirsty slug once 33s are fitted

[James W]

Diamater AND width is the issue here, particualy in the front where the wheel/tyre has to turn, the wheel arch looking from above is a rectangle shape, so is the tyre but inside the wheel arch, now visualise the trye as a rectangle rotating inside the wheel arch rectangle, it's the corners that will often hit first, it's worse at maximum articualation. With all the variables, tyre size, suspension lift and body lift it's hard is say, but I suspect you will have to do some trimming. Best thing to do is to do a trial fit and see for yourself, do explore maximum articualtion.

I had to trim the rear of the front guards and front bumper/spolier/plastic bit to fit 33"x12.5". In the front it was the 12.5" width that got me. In the rear no trimming required. My mu, suspension +1" and body + 1.5".

But lifts only lift the top of the guards, not the sides :-(

Yes, power dropps off a little, but not much for me, still climbs hills fine.... the key there is I think is power is the same but the ratio differant. i.e. your engine still produces the same power but it's like selecting slighty the wrong gear. Your speedo is thrown off a little so you actually are going a tad faster than you think.... however 34" I have not tried.

[adrian]

i think 255-85-16 is the equivalent of 33 10.5 16??

after the cost of the repairs i needed this week,

i'm not sure that i can now afford spare tires!

but they will be on the shopping list for my folks.

i'm not sure what size 34 inch tires come in
perhaps if they do narrow ones (like 10.5inch)
then they may fit, guess the best thing is a nice
friendly garage to visit for a trial fit

thanks for your help guys.

adrian

[geeves]

A more common size is 265x75x16 which is also quite similar.

[mudgrip4]

From memory I think 255/85/16s are about 33.4". They do run well on bighorns with a body lift - have a couple of aquaintances with them. Help with that bit of extra height under the diff. However when I asked the guy who runs those tyres, he recommended the 265/75/16s which are 32". Have done 23000k on these now and they've proved excellent on and off road. A very good setup - little power loss plus good clearance off road. Definitely take me everywhere that trucks with 33s go. I think others here have also found them an excellent tyre for on/off road work. Note I did do a 35-40mm shackle lift to fit them on my 88 Bighorn.

Mike

[nig]

Don't quite know what the obsession with 34" tyres is, they stuff up your gearing etc, but to each his own :)If you want to see tyre-sizes related to actual diameter try the manufacturers sites - eg www.bfgoodrichtires.com/assets/pdf/all_terrain_ta_kd.pdf
There is a lot of B/S in tyre size claims, go to the source and you know what equates to what.
If the chart doesnt show the size you want, then try a few combinations on www.tyresave.co.uk/tyresize.html

[mudgrip4]

Useful site - note mudgrips are often slightly bigger in diameter than figures these
charts indicate - as I think in many cases these sites give stats for road tyres. I agree with nig above - can't see need to jump from 33 to 34". There is a good range of tyres available at good prices for 33s (especially for 15" rims), but likely to be few options for 34s - and thus dearer. No real gain.

Mike

[Yarno]

There are many good reasons for getting the largest tyre possible, the rolling diameter for a start will help roll over larger obstacles, and the extra height actually lifts the diffs from the ground and you get less hung up on things, unlike suspension lift which leaves the diff the same height from the ground.

Just one other thing most tyre sizes are not the actual measured size most 33's measure 32.5" and some like the 32" Simex ET's measure 33.4.... and just like the tyres I just got for my MU they are 325/85 r16 which is supposed to be 37.8" actually are 38.7", so you need to look at the actual sizes too.....