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Off Road 18"s

122K views 663 replies 74 participants last post by  SNUKE 
#1 · (Edited)
I've been making up a list of some of the "harder" 18" tyres for off road use. I realised it might be of use to others and started to add in a few of the tyres which probably were not my bag, but went some way towards making it a "complete" list. I started to lose interest and appreciate it isn't complete, however as far as the tougher / more agressive tyres are concerned it's bloody close ;)

Note the percentage change figures are circumfrential, not radius (height increase) or diameter. I might add this in tomorrow with some other stuff I've missed / skipped... or not! :D

265/60R18 Factory 18"s = Baseline
Pirelli Scorpion ATR - Construction Not Specified
BBridgestone D697 - LT Construction

265/65R18 = 3.42% Increase
BF Goodrich AT - LT Construction

285/60R18 = 3.39%
General Grabber AT2 - LT Construction
Bridgestone D697 - LT Construction
Cooper Zeon LTZ

275/65R18 = 5.39% Increase
Falken Wildpeak A/T - LT Construction
General Grabber AT2 - LT Construction
Cooper AT/3 - LT Construction
Cooper ST
Cooper STT - True 3 Ply Construction
Maxxis MT764 Big Horn
Federal Couragia (not on website, found on eBay!)

285/65R18 = 6.77% Increase
Falken Wildpeak A/T - LT Construction

275/70R18 = 8.95% Increase
Mickey Thompson ATZ
Mickey Thompson MTZ
Cooper ST
Cooper STT
Cooper ST Max

Some of the bigger stuff is going to be a problem in the spare wheel well, and may even require wheels with less offset in order to push the tyre away from the upper control arm joint, which seems pretty close on my inspection. Anyway, this is a work on progress... I just thought putting it here might spark things up a bit.

Steve
 
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#2 ·
I've been making up a list of some of the "harder" 18" tyres for off road use. I realised it might be of use to others and started to add in a few of the tyres which probably were not my bag, but went some way towards making it a "complete" list. I started to lose interest and appreciate it isn't complete, however as far as the tougher / more agressive tyres are concerned it's bloody close ;)

Note the percentage change figures are circumfrential, not radius (height increase) or diameter. I might add this in tomorrow with some other stuff I've missed / skipped... or not! :D

265/60R18 Factory 18"s = Baseline
Pirelli Scorpion ATR - Construction Not Specified

265/65R18 = 3.42% Increase
BF Goodrich AT - LT Construction

285/60R18 = 3.39%
General Grabber AT2 - LT Construction
Bridgestone D697 - LT Construction
Cooper Zeon LTZ

275/65R18 = 5.39% Increase
Falken Wildpeak A/T - LT Construction
General Grabber AT2 - LT Construction
Cooper AT/3 - LT Construction
Cooper ST
Cooper STT - True 3 Ply Construction
Maxxis MT764 Big Horn
Federal Couragia (not on website, found on eBay!)

285/65R18 = 6.77% Increase
Falken Wildpeak A/T - LT Construction

275/70R18 = 8.95% Increase
Mickey Thompson ATZ
Mickey Thompson MTZ
Cooper ST
Cooper STT
Cooper ST Max

Some of the bigger stuff is going to be a problem in the spare wheel well, and may even require wheels with less offset in order to push the tyre away from the upper control arm joint, which seems pretty close on my inspection. Anyway, this is a work on progress... I just thought putting it here might spark things up a bit.

Steve
Thanks Steve - great info. I would add the Bridgestone D697 LT in the Baseline size of 265/60/18. It seems to be that these are the only LT construction in the OEM size, and a couple of the others on JG are using them.
Russell
 
#5 ·
Good research Barboots! Regarding a wider tyre option, there is no doubt they look cool. However, from what I have read, they may actually be disadvantageous in sand. This is opposite to what one would expect. The wider tyre has to push a wider bow wave of sand. Old Land Rovers with their skinny tyres had little difficulty in sand. OK, we aren't talking about much but my point is that it is a mistake to opt for a wider tyre thinking they will perform better in sand. Opt for wider tyres for bling only.

BTW, I went for D697's for the very reason that It4vette states. They are the only LT tyre available in the OEM size.
 
#6 ·
That certainly is the old story Bob, but the equipment has changed and we need to consider whether a "rule" or approach still applies.

The wider "wave" taxed the old asthmatic diesels terribly, but if you have the power to push it then it's less of a factor... eespecially if you can get more on top of it. Bear in mind it's mostly an issue as far as getting moving, as testified by all those smoking clutches! Also consider that the reduced gain in footprint from lower profile tyres could be offset by going that little bit wider.

The sand to the North of Perth is incredibly hungry, and I might have spent a thousand hours operating and directly observing almost every 4WD sold in Australia negotiating it. I agree... skinny high profile tyres with plenty of air out of them are best for for the old nags... but we've got ponies mate. :D

Anecdotally, I only noticed improvement when I ran 275's on my old Prado which came with 265's. That was going to a slightly harder carcass as well, which shouldn't help. It was a V6 petrol auto, so had reserve to push them.

I have no concerns about fitting wider than 265's in the context of sand driving. Clearance on the upper control arm ball joint is another matter, and may require an offset change. I'd rather not go that far again, though it's always tempting. :cool:

Cheers,
Steve
 
#7 ·
Does changing the offset to accommodate wider tyres (or for any other reason I guess), increase the load on the hubs or bearings enough to be a problem? Would it have warranty implications?
Thanks,
Russell
 
#8 ·
Yes Russell, the additional leverage can add to the load on the bearings. Whether this is significant given the huge inset of the standard wheels would be debatable. Currently they receive a massive leverage effect from the inside edge of the wheel, say if stepped up on a rock. Well that's my assessment of the situation anyway.

Anything seems to have warranty implications, however there needs to be a close association with the modification and any fault to have validity. If it was a bearing issue you'd probably be paying for it given Jeep's friendly nature.

I went from a -17 to a zero offset on my Prado. It has expensive "sealed for life" bearings and I had a slight concern that given the almost daily off-road use there would be a cost down the line. I've only done 70kkms since, but there's no hint of an issue.

I guess my last comment is that this time around these will be a second set of wheels for me, so the dealer will never see them :thumbsup:

Cheers,
Steve
 
#10 ·
Russell a key reason for the massive negative offset used today is to assist suspension design... I understand it is advantageous to have a longer pivot with independent systems, primarily with regard to scrubbing. I also believe it is beneficial for the design of the actual suspension dynamics.

Your edit is correct though... shifting the offset outwards does increase load during cornering. No argument there!

I'm struggling with the same concerns as you. No one seems to know whether the TPMS sensors will fit their Jeep specific aftermarket wheels! The market seems a void of intelligence, or give a sh!t factor at the least. Despite my wants, I'll probably go with an OEM Jeep wheel. That said I've got some -45 offset wheels on order "for a look"... the supplier is apparently OK to take them back. Do I buy 4x TPMS sensors online in anticipation of them working??? Probably, as any genuine 18"s I find without tyres will probably have had them stripped. That's my position... as of today :lol:

Why not buy 20"s for around town? There's a few about at the right price. If I were you, I'd sell the 18" tyres immediately... but everyone has a different angle to that!

Cheers,
Steve
 
#11 ·
Hi Steve,
Where I live, I just about need the height of the 18's just to drive on the rotten pot-holed roads. I have a Merc with 45 and 35 profile tyres, and have wrecked 3 rims (and $450 tyres!) in two years. So, even if I wasn't offroading, I would have gone for the 18's on the Jeep.
With the TPMS, probably the only way is to look at an OEM wheel with the tyre off, and the potential aftermarket, and try to compare them. The only thing I can think of is the width of the "ledge" the valve stem goes through, or the angle of it so the sensor doesn't get in the way during tyre removal. Jeep are VERY specific about how to remove and replace a tyre - so much so I'd be amazed if Bob Janes' followed the procedure.
Thanks, Russell
 
#13 ·
Thanks Doug. I went through the Cooper range early on when I was just looking for myself, skipping the AT3's in favour of their more agressive options. I must have missed the AT3 when I came back to "complete" the list.

They are certainly worthy of inclusion, especially given their close to OEM size. I can't edit my first post again, so once all my oversights are pointed out :eek: I'll re-post fully amended.

Thanks again,
Steve
 
#17 ·
I think any TPMS equipped wheel is going to require this kind of attention. Having the pressure point of the mounting equipment not pass the sensor is going to apply across the board.

Part of need for this cautionary note is in response to the care factor of the average fitter... which will be none. The job has to be spelt out precisely.

Steve
 
#18 ·
I think any TPMS equipped wheel is going to require this kind of attention. Having the pressure point of the mounting equipment not pass the sensor is going to apply across the board.

Part of need for this cautionary note is in response to the care factor of the average fitter... which will be none. The job has to be spelt out precisely.

Steve
I just noticed this:

The TPM sensors are designed for original style factory wheels. It is not recommended to install a tire pressure sensor in an aftermarket wheel. (This could cause sealing and system performance issues.)

Its not talking about damage as I thought, but is even harder to explain imo.

Russell
 
#20 ·
Can someone who has the Bridgestone D697 in 265/60/18 measure the actual tread width please.
I have just measured BF Goodrich in 265/70/17 (on a Prado) and the tread width was 220mm, not 265mm, so want to know what the D697 are.

Could someone who has the Yokohama A/T3 (I think Sparky has these) do the same please.

I wonder what the tread width of the Bridgestone D697 in 285/60/18 is?

If there are any others with different brands that could do the same it might help.

Thanks.
 
#21 ·
On the tirerack.com site they have all the tyre dimensions including treadwidth (which is invariably different to the section width (eg 265) which is sidewall to sidewall on a specified rim size).
Unfortunately, they don't seem to sell the D697, but maybe the D695 is similar. Click on the tyre and then the "specs" tab.
I had a problem with the inner edge of my rear tyres on another car scrubbing, and changed from one brand to another , with a 20 mm treadwidth reduction (both 255/35/18's), and the problem disappeared!
Russell
 
#25 · (Edited)
Reading the latest TSB sheet (Sept 18), there is an issue for another region (supposedly not relevant to us?) about a tyre problem with the oem Khumo 265/60/18 A/T's. Amongst other things, it says that if the tyres are replaced by the lower speed rate Michelins (190km/h vs 209 km/hr), then "it is required the control module be replaced and flashed with a lower speed rated software".
It would seem then, that if I replace the khumo's whit D697's (180km/hr), then I may need the control module replaced and flashed.
Does anyone know what this flash does? And why it would be a module REPLACEMENT as well? I would guess it is only for something like the speed limiter, but maybe it also impacts other functions I can only imagine.
Thanks,
Russell
 
#26 ·
Reading the latest TSB sheet (Sept 18)...
Russell
You're hitting the reading pretty hard Russell! ;) Good stuff mate, and respect.

My understanding is that this currently isn't so much an issue here, though I'm in WA and legislation will be different between the States. In WA, 4WDs have been issued scope to fit lower speed rated tyres, provided the vehicle does not exceed those speeds. I recall most states had provisions that were much the same... though things change. It was some time ago since I was across this topic.

I hope in the drafting of the new National code for vehicle modifications they take a common sense approach to this topic.... after all, the speed limit is 110km/h after all! :rolleyes:

One thing is for sure, and that is insurers don't so much care. Unless there's a Police report stating tyre failure was an issue no one is going to even think about knocking back your claim. Besides, it's arguable in court... they just couldn't be bothered.

The uncertainty in the modifications arena makes product selection awkward. Just how much offset can I change, how far up in diameter can I go and how much wider??? Speed rating reduction fits into this exact same basket, and until the authorities give us clear direction we're left juggling.

All that said, I don't think that in any time soon my dealer is going to insist they flash my Jeep because I've rolled in on nasty N rated muds! Remember these are the guys trying to deliver cars in the wrong colour! :lol:

Steve
 
#30 ·
275/65R18 fit without grief though the spare wheel well will protest a little, especially if they have a square shoulder.

From there up it could require an offset change, and the guard liners would be "very close" :eek:

Cheers,
Steve
 
#32 ·
I just replaced my OE Kumho 20's with some Pirelli Scorpion ATR 265/60R18's fitted to OE 18's. They look great... I have noticed they're a little noisier than the OE Kumho's (to be expected) but I really need to turn the music off to notice... I will have to take them for a decent run and let you know my thoughts otherwise.
 
#34 ·
Yes, just at Jax Bowen Hills. They had to order them which took a few days so I am sure any local store could source them. Happy with them so far...
 
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#35 ·
I have just put together a set of 18" rims for my GC to compliment the 20's I usually run, after picking up a set of Laredo rims of ebay I painted them gloss black to match the Jet edition theme. Then after plenty of research I went with some Hercules Terra Trac tyres in 265/60/18 these are made in the US and at $220 each fitted and balanced are a bargain, considering they will sit in the shed probably 8 months of the year. Being the same rolling diameter as the 265/50/20's meant that the spare also fits in its spot with all the storage bins.
 

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#37 ·
Thanks Steve,
I have on order a JCG Overland with ORII package, I have already purchased another spare so I can run 2, I have discussed with our local tyre dealer to swap out the tires to the Cooper AT3, good to see some info especially on the % well done :thumbsup:
 
#38 ·
Excellent... and I'm gad to be of some assistance shelhall. Given you have a wait for your Grand to arrive, keep watch for new tyres coming online in your preferred size. For example, Cooper Tires Australia said that the ST Max might be available in 275/65R18 early-ish 2014. They caught my attention enough to chase up an ETA... it's a pity I need to sort something out earlier.

Anyway my point is that there may be some interesting releases over the coming months.

Cheers,
Steve
 
#40 ·
The Cooper prices are a bit hard to swallow Brenden. Have you seen Noon's Falken AT fitment, or the recently posted Hankook AT pictures? At a $375 (I think) and $220 respectively, they offer serious savings over the Coopers. I'm going to fit General Grabber AT2 at $360 a corner, which is a good deal for a 3 physical ply carcass.

Are the Cooper AT3s two or three ply physical construction in 275/65R18?

Cheers,
Steve
 
#41 ·
Good questions there Steve,
The main reason is that I have used coopers for many years and have found them awesome quality, I will do some more research as I have till mid Jan to sort this out and I agree the cooper pricing is over charges allot.

I have been caught before changing tire i.e I currently installed the Yokohama Geolanders G12 on my 4wd and I think they are absolute crap, would never recommend these tires to anyone. compared to the coopers I used there is no comparison what so ever. The only reason is the company I had to use was not a cooper dealer. :-(
 
#46 ·
Finally got around to getting our 18's (Mopar 82212377) and D697's on the GC today. Very happy with the result. Tyres are standard 18" size (265/60/R18). The ride is a little firmer than stock 20's and there is an ever so slight hum that you can only hear with radio muted and if you listen for it. :cool:
I've got the same tyres except with the white lettering on the outside. So what tyre pressure did they tell you to use?
 
#47 ·
So guys when you change from 20s to 18s what other changes need to be made does the speedo need re flashing ? Do the new TPMS hook up ok? Looking at changing but not sure all the implications of doing it
 
#53 ·
Just dredged up some info on the Terra Trac. OEM size in 18" is a Passenger construction carcass by the look of it, but the regular upsize is available in LT construction. Not that the number of physical ply are mentioned. Check out via the link below... AT, then Sizes and Specifications

SUV/Light Truck Tire Gallery | Hercules Tires

It seemed too good to be true :eek:

Cheers,
Steve
 
#58 · (Edited)
Just closing the loop on my solution.

Bought:
- 18" Laredo wheels off Claremont Wheel Power in NSW and had them freighted.
- TPMS sensors off a US seller on eBay
- General Grabber AT2s in 275/65R18 from Claremont Tyre Power in WA

This is the result in pictures:













Yep, of course they are noisier. It's all low frequency sound similar to the background in a large aircraft... or wind roar. There's no high pitched element.

Speed is about 3 to 4% shy now.

TPMS just picked up without an issue.

Even with rough treatment off road there's been no contact, except for one area at the leading edge of the rear wheels. I recommend trying to hold back the guard liner here either by shaping with a heat gun or pinning back with some Sikaflex. The guard liner doesn't have to hit... and only one side wore through.

Tracking is a bit worse. That's a square shoulder issue... the benefit is solid gravel road cornering. I drove some loose roads like a demon and the grip was fantastic through corners... more than I dared find the limit of. Lowering the pressure improves bitumen tracking but adds a little bit to the fuel consumption.

Fuel consumption up to around 10 l/100 unless pumped up real hard.

Requires low pressure to deform. I ran 12psi in some really powdery wind swept sand, and could have gone lower to get the flotation I wanted. Oh for 16"s again...

At around two grand all done, I have the best of both worlds with both on-road and off-road boots for my Jeep. I'll probably chase up a slightly narrower tyre for the spare unless I do a bit of rear storage work. Currently I just have the standard spare and the threat of a very slow trip out!

Ciao,
Steve
 
#59 ·
Thanks Steve,

I have bought my 6th spare of Claremont Wheels as well and got freighted to Alice Springs, I have got the dealer to order the TPMS for that wheel as I was informed that you had to have it matched to the existing vehicle monitoring system.
As for the tyres, man that's hard, I have been doing so much research on what to get to fit it out to work and look good.as well as great reviews but getting whopping prices from $450-$550 a tyre alone and needing 5, gets very expensive. and they will not give me anything for the current Michellens that will be coming on the vehicle either so that makes it costly.

Cheers
Brenden
 
#61 ·
Just had a look the only problem with them they are a 4 ply not 5, so more of a mud terrain that a all terrain tyre. would not think you would get good km of the highway as well as slippery in wet?

cheers
Brenden
 
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