Max tyre size conundrum

IllussionIllussion Junior Member
edited August 2017 in Wheel's and Tyre's
I've been trying to plan some future modifications to my vehicle, and when I looked at the tyre component I found some interesting stuff. Surely I'm not the only one with this problem though.

So I've been considering what sort of lift I want to have on my vehicle if I want to future proof it for larger tyres down the track. This led me to check on the vehicle modification guidelines and the NCOP for how to make sure my vehicle can still be registered. So putting aside the other parts of a lift: If we ever want to put 35" wheels on an amarok, or actually, anything above 32" I think we are in a bind.


NCOP VSB 14 Section LS - Section 4.24 states that tyres 'Must not be more than 50mm larger or 26mm smaller than that of any tyre designated by the
vehicle manufacturer for that vehicle.'

Well bugger, looks like we can't do it under a basic modification and it needs to be assessed by an engineer under section 5: certified modifications.

Let's use Code LS7 High Lift 50mm-150mm, that's more like it.
Section 5 Code LS7 Part 4 Wheels and Tyres 'The overall tyre diameter can be increased to allow an increase of 7.5mm in vehicle height for passenger vehicles and no more than 25mm in vehicle height for four wheel drive vehicles (typically MC ADR category).'

Well, that's exactly the same as Section 4. Has anyone any advice for how to navigate this minefield successfully? Has any states been willing and able to assess mods that are only just outside the scope of the NCOP guidlines?

Comments

  • McRokMcRok Member
    edited July 2017
    Illussion wrote: »
    So putting aside the other parts of a lift: If we ever want to put 35" wheels on an amarok, or actually, anything above 32" I think we are in a bind.

    I can't answer your question, but query why you would want to put 35" inch wheels on an Amarok?? Mine are just under 32" and only just fit. It rides like a billy cart and uses too much fuel. The auto gearbox works much harder on hills and the spare won't fit under the car. My next set of tyres will be smaller. Sure you want to do this?
  • rokerroker Member
    edited July 2017
    I'm sure I read in [MENTION=190]dave[/MENTION] project build thread that he was running 33"s.

    35"s would scrub big time without major butchering the rear of the front guards.

    And as [MENTION=2734]McRok[/MENTION] pointed out you will also stuff up your gearing, especially if it's an auto.

    I believe Dave kept his lower-ratio manual diffs when he converted over to an auto, and he posted that his gearing with 33" worked out the same as an auto on standard tyres.
  • IllussionIllussion Junior Member
    edited July 2017
    Thanks guys, interesting points. I might hit up some people on facebook that have done a tyre size upgrade to see if they had any mechanical difficulties.
  • darbiodarbio Senior Member
    edited July 2017
    I put 265/65r18 BFGs (about 31.5") on mine.
    Wouldn't go bigger, the speedo is bang on now.
    The tyres fill out the wheel arches nicely. No lift required. There's not much spare room in the wheel arch for bigger tyres.
    The spare just fits underneath. [MENTION=60]SAROK[/MENTION] has the same.
    e570f447b1fd56948742545c6cc43cc9.jpg61b2bba7b11f751d62fc1c5ce2d289ba.jpg


    Sent from my iPhone using Tapatalk
  • fedete1995fedete1995 Junior Member
    edited July 2017
    darbio wrote: »
    I put 265/65r18 BFGs (about 31.5") on mine.
    Wouldn't go bigger, the speedo is bang on now.
    The tyres fill out the wheel arches nicely. No lift required. There's not much spare room in the wheel arch for bigger tyres.
    The spare just fits underneath. [MENTION=60]SAROK[/MENTION] has the same.
    e570f447b1fd56948742545c6cc43cc9.jpg61b2bba7b11f751d62fc1c5ce2d289ba.jpg


    Sent from my iPhone using Tapatalk

    Hey guys!

    Another thread I like!!

    I've gor BF KO2 275/65R18 on the same Durbans, they have been there for 10.000 km now, previously I was using Dick Cepek Trail Country AT, both LT E-Rated.

    I'm in love with the BFs, great tires, much better than the DC, especially when dry cornering and wet handling overall, and a tad comfier.

    The DC lasted 40.000 km, that is actually a lot more than the P-metric Geolandar AT-S I used to buy for my previous Amarok (18.000 km), I'm suspecting this BF won't last as much as the DC, but I don't really care, since they are A LOT better.

    The size I have is around 32.1", and is all good, the only issue is a light rubbing with the UCA, but I have already bought longer wheel bolts and designed 12-15 mm wheel spacers, with the right chamfers and so... So I'm just waiting to make them with 6061-T6 Aluminium with a CNC machine, because I have the CAD now.

    I'm planning to make them "anodize" the spacers, to prevent them from sticking to the Hub because of corrosion.

    Anyway, I'm really happy with the 32.1" BF KO2s, but I'm pretty sure that on a 17" Aldo wheel would rub heavily with the UCA, because of the different offset.

    Greetings from Colombia!

    Federico

    EDIT: I forgot to say something, 32" tires might fit with 17" Aldos, but not with 275 width tires, maybe 255 or 265 (the last one might still rub), but the worst wheel offset is that from the 16" taruma wheels, everything over 31.5" hits the UCA.

    They don't touch the UCA when the car is parked or turning the steering, but somehow, they do, maybe when jumping or cornering...
  • TazaTaza Senior Member
    edited August 2017
    I've got 285/60r18 with Nitto Terra Grapplers on the stock durban wheels. They go pretty good and make the truck look much tougher
  • darbiodarbio Senior Member
    edited August 2017
    Taza wrote: »
    I've got 285/60r18 with Nitto Terra Grapplers on the stock durban wheels. They go pretty good and make the truck look much tougher

    Any pics? Any rubbing?


    Sent from my iPhone using Tapatalk
  • TazaTaza Senior Member
    edited August 2017
    There is a very slight rubbing on full righ hand lock but other than that none. I dont have mudflaps on and I have a tough dog suspension lift at the front
    IMG_2851.JPG
  • tikiphiltikiphil Member
    edited August 2017
    35s no wheel arch modifications apart from the bullbar d86d7b71b2139bf5eea847a662867213.jpg


    Sent from my iPhone using Tapatalk
  • rokerroker Member
    edited August 2017
    tikiphil wrote: »
    35s no wheel arch modifications apart from the bullbar

    What size rubber?
  • tikiphiltikiphil Member
    edited August 2017
    roker wrote: »
    What size rubber?

    315/75/16


    Sent from my iPhone using Tapatalk
  • rokerroker Member
    edited August 2017
    tikiphil wrote: »
    315/75/16


    Sent from my iPhone using Tapatalk


    Hmmmmmm....... them is big. :D
  • fedete1995fedete1995 Junior Member
    edited August 2017
    roker wrote: »
    Hmmmmmm....... them is big. :D

    "Big" is not enough!! They are huge, massive, enormous, etc...

    What a nice truck, looks great!! I didn't even know you could fit 35s in the Amarok :D
  • dom15coredom15core Junior Member
    edited August 2017
    How much lift are you running mate? How re the CV's coping?
  • tikiphiltikiphil Member
    edited August 2017
    2inch lift, 43mm body and a diff drop kit, all work was done in the first 5k and has 50k now still going strong


    Sent from my iPhone using Tapatalk
  • NZ HunterNZ Hunter Junior Member
    edited August 2017
    Auto or manual Tiki? How's it affected your gearing, especially reverse if an auto?
  • edited November 17

    Old thread I know but in case anyone else coming across this point, wanted to add my experience:

    I'm running an Outback Armour Adjustable Bypass kit which gives a lift of 35-40mm front and rear. Manual my17 Core Edition dual cab.

    Not a huge lift, but it's enough to run 31.5 inch tyres without any rub.

    Now, with 33s on, no body lift required. You need +20mm rim offset to clear the factory UCAs without issues. Putting Blackhawk UCAs in this month, in theory no need to change the offset but will update if so.

    35s need the 43mm body lift, suspension lift and diff drop as mentioned by tikiphil to avoid stress on the CV joints. Tikiphil's feedback indicates no mechanical issues with this setup, and I've heard the same from others, one day would love to see it on mine but I have no need.

    Gear ratio changes aren't available for the Amarok manual, I've been heavy into finding this out and no, not available in the current market. Your main expected gearing issues with larger tyres would be while towing or while in 1st gear low (might roll too fast). However, the 33s have absolutely no gearing issue on the 4cyl manual as noted by users above and my own experience. Mild increase in fuel efficiency in highway driving is seen, ODO is slightly off but not an issue for me, just be aware of it. Unsure of Tikiphil's experience on 35s (if it's a manual). Can't comment on the 4cyl autos unfortunately, but I do know those who run 34s on the V6 auto with no gearing trouble.

    Any gearing drawbacks will be helped by a 3" exhaust setup and/or ECU remap in my experience.

    Hope this is useful in some way.

    Cheers

    EDIT: P.S. Frederico you don't need to go to all that trouble to fix the UCA rub, just get offset rims! :D

Sign In or Register to comment.