Everything about tires for LR4/ LR3 with 18" wheels

[Dubai78]

doesn't quite fit the thread title, because I think they are smaller than 18".
Are these 17"? And if so, because they are diesel? Pretty fun video anyway.

They look like 17 or even 16s. likely running much smaller brakes.

 

[Surfrider77]

Bartek,

I currently plan on ordering the KO2's in 285/60/R18.

I have a really great dealership but plan on using an Indy shop to do my mods: they are cheaper and seem more accustomed (not-to-mention enthusiastic) to do off-road mods (and I have a lot of work to do).

All my stuff won't be in until May-ish, but discussions and initial measurements lead me to believe that this size tire, which is both wider and larger (diameter) than the stock, will cause a few surmountable issues.

First, the tire is taller so we will need to get a set of rods as well as recalibrate the height sensors to level the truck properly.
Second, these wide tires will rub on the plastic splash guards/wheel wells. Thus, some minor wiring of the plastic to the body of the truck is necessary to give us a bit more room in the wheel wells.
Third, the bigger tire will probably have trouble in the spare-tire well so we will most-likely need to cut the plastic heat shield/splash guard and then wrap the exhaust at those points (to protect the tire from getting scorched). Positioning the bigger tire in there may be a bit tricky, but should be do-able.
Finally...and this is something relatively unrelated to driving the truck but a problem for those with a wheel carrier...I have learned from Finlayforpres that I will need to fabricate an entirely new spare tire mount on my Kaymar rear bumper since the oversize tire needs more space (and the factory mount is not well positioned anyway).

I hope to let everyone know how the mods go and I will post pictures after the latest round of mods are complete. She should look pretty beastly after all the work...

If anyone has experience with the 285/60/R18 on the LR4--let us know!

Cheers,
Land Rover Joe

You absolutely do NOT need to do all of that work to accommodate 285/60R18 tires! They are actually just slightly smaller diameter than 265/65R18 (by a mere 0.1 inch). You do not need to run rods or a lift whatsoever.

I do not have any rubbing on the plastic from the increased width either. The only rubbing you get is at full lock at the frame horn (diameter issue, not a width issue) just like everyone else. It is absolutely minor and rarely happens.

You will need to remove the exhaust heat shield and deflate down to about 8psi to get the spare to fit up under the truck. I have also rotated my spare in a 5 wheel rotation as to get even and longer wear. As the tires wear, if fits easier and you get less of that full lock rubbing.

Again, no reason whatsoever to run rods / lift full time, nor touch any of the plastic trim! Both the 265/65R18 and the 285/60R18 are the most common sizes people seem to run on the Compomotives without doing any modification work whatsoever. They are safe bets for 18" tire sizes.

 

[Land Rover Joe]

Surfrider 77,

That's great news and many thanks!

I will follow-up with the group once complete (late May?) to post how everything goes.

Land Rover Joe

 

[Bartek Bachorski]

Surfrider 77,

That's great news and many thanks!

I will follow-up with the group once complete (late May?) to post how everything goes.

Land Rover Joe

After considering my options and thanks to your encouragement I will be pulling the trigger on the 18 Compos (in silver, which unfortunately means extra charge!). I will be fitting them with the Cooper Zeons 285/60/18 tires. All your advice is greatly appreciated - my dealer/local shop wouldn't tell me a fraction of what you guys did!
What are your thoughts on ordering only 4 wheels/tires and keeping the original 19 wheel/tire (as it is right now) as the spare? That would save me the pain of dealing with the heat shield etc. In case of a flat, would temporary replacement of 18 wheel/tire with an original 19 wheel/tire spare be an issue? I am keeping my 19 wheels anyway, since I have winter street Blizzak tires on them (I need them for the winter city driving).
I will post pix once I install my new silver Compos and the 285/18 Cooper Zeons!
Cheers!

 

[umbertob]

The size of the spare wheel itself is not important, what matters is the overall circumference of the tire wrapped around it, which needs to be as close a match to the running wheels as possible. So, while you could definitely use the original 19" full size alloy in lieu of purchasing a fifth 18" Compo wheel, the difference in overall circumference between a stock 19" tire and the 18" oversized 285/60R18s you plan to purchase would be enough that the car would definitely notice, unless "limping" to a tire shop would only involve driving a few blocks, but that's almost never the case. Usually, when you get a flat with these A/T tires you are far away from civilization, let alone a tire shop. You may have trouble upshifting past 2nd or 3rd gear if you were to mount such a spare on the front axle, for example (the transmission would detect the different number of revolutions between left and right wheel, assume you were in a turn and prevent automatic upshifts.) Probably not a good idea if you plan on going off-road regularly.

At the very least you would want to upsize the 19" spare tire to something closer in overall dimensions to the Coopers, but that kind of defeats the purpose of not buying another 18" wheel and tire. If you are going to go as far as buying a set of 4, might as well go all the way and get a 5th wheel - and tire - to match, IMHO... The heat shield comes off by removing 3 small screws and you never need to worry about it again, and deflating and re-inflating the spare to make it fit under the car is not that big of a deal (you will need to carry a compressor with you in the car at all times, but all self-respecting owners of these wheels do, LOL.) It's a bit of a pain, but it's not as if you will need to remove that spare on a regular basis - hopefully.

 

[Surfrider77]

It is common advice NOT to run the stock spare with the oversized off-road tires. You end up with quite a bit of a rolling difference (diameter) and this will cause increased wear on the diff, if not outright damage at highway speed.

255/55R19 is 30.04 inches (stock)
285/60R18 is 31.46 inches

 

[Surfrider77]

Umberto beat me to it.

 

[Bartek Bachorski]

Great and thourough explanations, thank you both.
I didn't realize that much of a damage/trouble can be caused by mere 1.42" of a difference. Anyway, I am going to heed your advice and definitely get the 5th wheel - def. not so proverbial in this case, ha!
What also made me doubt the necessity of getting that spare at first, let alone lack of some knowledge you guys just shared, was the fact that when I was driving a 25 year old Land Cruiser for about a month last year, all of its tires, in addition to being worn treadless, seemed to also be different from each other - although the wheels were the same, I think. Granted we rarely drove faster than 60-70 km/h (we had three people, petrol canisters, water, food, grill and heavy tents with us) we didn't experience major issues, although it did feel a bit wobbly and "fluid", if you will.

Last question: if I remove the heat shield, is the tire not gonna get scorched? Or other issues?

Also, I suppose I will have to replace the spare with my original 19 spare every time when I put my winter wheels/tires back on/off, but that's ok, I'll just get really efficient in replacing the spare I guess
Air compressor permanently in the car - good idea!

Maybe I'll get some shields for the undercarriage/gas tank etc. I suppose hitting a larger rock or sliding into gully could easily damage some vital parts. Not sure about reinforced front/rear bumpers...overall everything I'm mentioning shouldn't be more than $10k (I'd hope), but can save tens of thousands in repair/replacement. Do you guys agree and what is the most important protection in your opinion?
I'm gonna end up with a pretty well equipped vehicle if I go thru with half the improvements on this wishlist...
Thx again!

 

[epiclr4]

Great and thourough explanations, thank you both.
I didn't realize that much of a damage/trouble can be caused by mere 1.42" of a difference. Anyway, I am going to heed your advice and definitely get the 5th wheel - def. not so proverbial in this case, ha!
What also made me doubt the necessity of getting that spare at first, let alone lack of some knowledge you guys just shared, was the fact that when I was driving a 25 year old Land Cruiser for about a month last year, all of its tires, in addition to being worn treadless, seemed to also be different from each other - although the wheels were the same, I think. Granted we rarely drove faster than 60-70 km/h (we had three people, petrol canisters, water, food, grill and heavy tents with us) we didn't experience major issues, although it did feel a bit wobbly and "fluid", if you will.

Last question: if I remove the heat shield, is the tire not gonna get scorched? Or other issues?

Also, I suppose I will have to replace the spare with my original 19 spare every time when I put my winter wheels/tires back on/off, but that's ok, I'll just get really efficient in replacing the spare I guess
Air compressor permanently in the car - good idea!

Maybe I'll get some shields for the undercarriage/gas tank etc. I suppose hitting a larger rock or sliding into gully could easily damage some vital parts. Not sure about reinforced front/rear bumpers...overall everything I'm mentioning shouldn't be more than $10k (I'd hope), but can save tens of thousands in repair/replacement. Do you guys agree and what is the most important protection in your opinion?
I'm gonna end up with a pretty well equipped vehicle if I go thru with half the improvements on this wishlist...
Thx again!

With these modern vehicles and the ABS systems, traction systems and tire pressure monitoring systems tire size's not matching can throw everything for a loop pretty easily. Painful really, if only there were less stupid people in the world....

As for the heat shield, no one has ever been on here and complained about their tire melting. You should be fine.

As for swapping the spare on and off, its isn't really that painful of a process. If you have never done it, simply pull out the little hook from the bag in the back of the vehicle. Open up your 3rd row seats, pull up the little black flap, insert hook and start turning. Tire drops down super easy. Shouldn't take you more than about 10-15 minutes to swap the spare.

Where are you located? I know umberto and Fin have different sliders and skids as well as one other person. They will chime in I am sure but I always thought the Pro-Speed group out of the UK had the best system. Only issue with them is the cost of freight to get it here as there is no US vendor to help with the shipping cost.

 

[Bartek Bachorski]

Yeah, I'm getting that spare for sure. Thx for reassurance reg. the heat shield. And getting that spare on/off for winter/summer will only make my job easier if I ever really need to do it, which I most likely eventually will if I have enough fun out there.
I'm located in Chicago, but will check out Pro-Speed online to see what I am looking at.
The more I think/read about it the more I am convinced that skids/rock sliders as we'll as solid bumpers are a good idea if I don't want to be confined to parking lots or cause some substantial damage while on the trail. I guess you shouldn't bring a knife to a gunfight