30' or 31' MT tyres on IFS?

Jackal · Thu Feb 16, 2012 4:49 pm

I'll be putting on some new MT tyres next month (Maxxis Bighorns) but can't decide if I should go 30' or 31'? What do you guys think?

Thu Feb 16, 2012 5:28 pm

Hi Carl,

In your instance with the 2.7i Motor i will opt to fit 31" tyres on the IFS. they do fit and clear the wheel arches nicely under articulation. Also the 2.7 has the power to handle 31 tyres.

I just looked up in a brochure and the 4x4's came out with 265/75R15 tyres which = 31" tyres. So 31 is standard size for the IFS 4x4's.

Thu Feb 16, 2012 7:02 pm

Hi Carl, please let me know of place with outstanding prices as i have been looking for 31 for some time now, but i can not see what makes these tyres so expensive. because it is more frequent buy? or because it is a slow seller? my best price so far is on Pirelli Scorpions Mud terrains for R 1750 per tyre incl fitment and ballancing.

Thu Feb 16, 2012 7:19 pm

31x10.5x15 M/T

Besides what's stated above, your truck will also stand higher compared to the 30's

Thu Feb 16, 2012 10:20 pm

Yep, 31's will do nicely.

Jackal · Fri Feb 17, 2012 9:05 am

I see on http://www.um.co.za/specifications/toyo ... 2002).aspx that my bakkie came out with 245/75 r15 which is a 30' isn't it? And won't the extra 1' (25mm) only effectively lift the diff another 12.5mm? So is it really worth changing the standard set up for such a small gain? What do you think the fuel economy difference would be? I have 245/75's (Conti AT) on the bakkie at the moment but have had 31's (Cooper ST) on before. I found that my 2nd gear in traffic was a little underpowered with the 31's but obviously the off-road performance of the 31's was better. Decisions, decisions...

Fri Feb 17, 2012 9:11 am

31" def, for R150 difference per tyre. i am def going the 265 toute

Fri Feb 17, 2012 9:25 am

The bakkies came out with 245/75 r15, but the 31" just look so much better.

Fri Feb 17, 2012 9:26 am

Most guys run 31's with their 4Y motors. You really shouldn't have any issues with the 2.7.

Ja, you only gain ½" diff clearance, and it helps a little but it's not just about diff clearance, a combination of small benefits, actually. The footprint is marginally increased, especially when deflated ... fuel economy may sometimes be improved (lower revs for the same speed) but depending on your driving style ..... and to me the most important benefit is over rough terrain where a larger circumference tyre doesn't drop into a depression / hole / rut as far as a small tyre would, so that on it's own helps with ground clearance as well as approach, departure and break-over angles. Additionally it may make all the differrence in keeping traction on all fours instead of lifting a wheel.

So go for the 31's, .... and it also looks better!

4x4Maniac · Fri Feb 17, 2012 12:09 pm

What will the speedo do with 31" compared to 30". My feeling is it will turn slower when the speedo shows you are going at 120km/h and also the actual mileage will be less, because of a bigger circumference?

GeorgeJvR · Fri Feb 17, 2012 12:39 pm

A friend just fitted 31" on his KZ with std suspention and the wheels are toutching under articulation when turned. "behind the front wheel"

ROBERT · Fri Feb 17, 2012 3:41 pm

My 31's rubbed slightly at the front with std suspension. put just OME shocks in and the problem was gone.

Fri Feb 17, 2012 4:54 pm

4x4Maniac wrote:What will the speedo do with 31" compared to 30". My feeling is it will turn slower when the speedo shows you are going at 120km/h and also the actual mileage will be less, because of a bigger circumference?

Not sure about the IFS, but suspect that it will be a similar scenario to the SFA since all speedo's over-read a bit. With the SFA the speedo is far more accurate although I'm not sure about the odometer since I've never checked it.

Fri Feb 17, 2012 6:31 pm

Both White Fang & Hound Dog are now fitted with 31" Bridgestone Duellers. WF has an OME lift, HD has standard suspension. No problems with either and speedometer now only over-reads by about 1 - 1.5%, compared to over 7% before.

-F_D

yotaman · Sun Feb 19, 2012 8:20 am

Hilux 1 wrote:Hi Carl, please let me know of place with outstanding prices as i have been looking for 31 for some time now, but i can not see what makes these tyres so expensive. because it is more frequent buy? or because it is a slow seller? my best price so far is on Pirelli Scorpions Mud terrains for R 1750 per tyre incl fitment and ballancing.

Tertius thats a good price for good rubber! From whom / which franchise dealer? I want to test that deal here in Gauteng please.

Sun Feb 19, 2012 9:07 am

I hear Rivonia Tyres in JHB have the best prices up there. If only they had a branch down here..............

Sun Feb 19, 2012 9:17 am

goodhope tyre

Jackal · Mon Feb 20, 2012 11:19 am

Interestingly when I had my 31' Coopers on my odometer and speedo were actually exactly correct. I measured a trip from CTN to Upington with the GPS and it was literally exactly the same. I also found the speedo almost exactly matched the GPS with the 31's. With the standard 245's my speedo and odo are actually out of sync with the GPS. I did get some mild 'scraping' when having the steering in full lock with the 31's but nothing serious. I'm running Monroe gas shocks (came with the bakkie when I bought it) but will be replacing with OME when they're poked. I think I'm leaning towards the 31's again...

4x4Maniac · Mon Feb 20, 2012 11:27 am

So as jy wil he jou trok moet lae kilos op tel, sit groter tyres op! Maw my bakkie het eintlik 220k km's op ipv 240k km's

Bugs272 · Sat Apr 16, 2016 1:45 pm

I own a 2015 hilux 4x2 3.0L D4D about to put new tyre on my lax. I know 31x10.5R15 fit without rubbing. I wonder if 32x11.5R15's would fit? Without putting spacers on the front struts. If I would need spacers what size would I need? 25mm or more?

Any advice please