Wheel and Tyre size advice

[vvulture]

Hey guys,
Relatively new to the whole 4WD scene so please excuse my ignorance ( if any ).

Currently have a 2018 JKU with stock 18" rims and 32 inch road tyres 255x70x18

I need to mention upfront that i want to stay within legal boundaries and i'm in NSW.

I'm having a 2 inch lift done next week but need advise on tyre/rim size.
My understanding is that i can go up to 33 inch wheels which would take me up to the 2.5 inch ( 75 mm ) legal lift limit. Please correct me if i'm wrong.
I would like some recommendations on RIM sizes and TYRE sizes to suit the rims.
I see a lot of people reducing their rims size to 15 or 16 inch, but is that even legal ?
Current tyres are 255 mm wide. Whats the max width i can go up to legally ? My understanding is that the wheel track can be increased by 50 mm but not extend out past the guards, and then there's the whole offset thing to take into account..

It hurts my head lol.

Thanks guys, hope i'm making sense..

[Thol]

Re your first calculation, going from 32" to 33" is only lifting 1/2" or about 12mm.
With a 2" susspension lift you'd be left with 1" radius increase or 2" diameter to stay within the 75mm overall.

[vvulture]

Originally Posted by Thol

Re your first calculation, going from 32" to 33" is only lifting 1/2" or about 12mm.
With a 2" suspension lift you'd be left with 1" radius increase or 2" diameter to stay within the 75mm overall.

Hey Thol,

You are correct. I would end up with a 2.25 inch lift rather than 2.5.
But i was advised that the lift may be a little bit over the rated 2 inch so i'm playing it safe.

***EDIT*** Sorry i double checked and gave you all a bum steer. I'm getting a 2.5 inch lift.. which should end up just shy of 3 inch with 33's.
***EDIT 2*** Sorry tripled checked. It's a 2 inch lift i am having done... you can't legally do more than 2 inch suspension lift. But i could go a a little higher on the tyres if i wanted to, closer to 34 inch.

[Blugeepunlimited]

Pretty sure you will find you cannot go to a smaller diameter rim due to the size of the front brake rotors/calliper assembly

[vvulture]

Originally Posted by Blugeepunlimited

Pretty sure you will find you cannot go to a smaller diameter rim due to the size of the front brake rotors/calliper assembly

Right, didn't think of that.. but aside from that what are the legalities ?

[Jeep'ers]

Okay, you’ll rub on 33s on the sway bar so you’ll need to get a better offset rim, then you could go to a 34 with the lift to stay within spec that you want and will have next week...

The front brake assembly is the same from what I’ve read and seen and you could go to a 17 from an 18

That is the brakes haven’t changed since 2012...

Sent from my iPhone using Tapatalk

[relwell]

If you're a law hawk as well be sure to pay attention to your track width like you mentioned.

Beefier tires like M/T's or a new rim offset all add up and will stretch that out. Check the height measurements at the front and rear of the vehicle to ensure your ride height is good. I got a talking to as my new rear shocks pushed me up 3mm over the limit. I put some a heavy gear box in the back and solved that problem although had money allowed a heavier bumper would have been my first choice.

Thank goodness math is fun!

As for the fenders you can go big bucks and get a set of extended flares, go less big and grab extender brackets, or go less less big bucks and bolt on some rubber fender extender (or any appropriately fun sized rubber stripping) to your fenders to cover those wheels. I recommend doing this right away as it is probably the easiest spot for someone to see you're not within the law at a glance.

Oh and mud flaps. Make sure you have them and they reach low enough and cover the tire width.

Good for you trying your best to keep it legal. It is clearly a major effort and we appreciate that.