Jeep Garage  - Jeep Forum banner

20" Tyre Thread

99K views 389 replies 73 participants last post by  BobT 
#1 ·
Just when I thought my Khumo (korean for crap) were going to last more than 20,000km, it appears they will need replacement in the next few weeks.

I am hoping that we can get some ideas on what we can get locally and imported for our cars. This thread is only for the 20" tires, as the 18" have more selection.

Can people who have non OEM tires report they success/failures on replacement tires for our cars.

I am after road tires, not offroad, but this thread is for all types.
 
#288 ·
Stock 265/50R20 - would love to go a taller sidewall for added protection, but I feel going wider and taller would instead achieve the opposite when you are then bulging the sidewall at full pressure and then flexing it further with reduced pressure offload. If I feel the need to address that in future I'll swap the wheels to 18".
 
#289 ·
Why would you air them up to full pressure?
I've up-sized tires on just about every car I've owned and never had an issue.
I'm running 285/50/20 Blizzaks right now and there is definitely more stability from the wider contact patch and added rim protection.

I guess you've never seen some of the monster tires the JK guys throw on and take offroad with no issues.
 
#298 ·
I'm almost ready to go with the terra grappler g2 in 265/50/20. Love the look and all the positive comments. A couple of lingering issues though:

- almost all off road driving I do is on the sand (Fraser, Moreton, etc), so wondering if the tread pattern of the g2 is overkill. Would a HT actually perform better? I've always worried that the khumos are too fragile, and too easy to puncture on certain tracks, particularly around Kingfisher bay or Wathumba.

- I'm very, very, tempted to upsize to the 285/50/20, but do not want to swap the stock spare. If I did get a flat on the island could I still use the stock spare given the diameter difference? My thinking is that even if it is on the rear the ELSD should be able to handle the difference as its not actually locked in most instances, but my confidence in this assumption is low...

Any comments appreciated.
 
#305 ·
This is probably not what you want to hear but honestly, if "almost all" of your off-roading is on beach sand, you are better off sticking with your OEM passenger tyres. Successful sand driving is all about floatation. There are specialised floatation tyres for golf buggies, farm equipment etc. but an aired down passenger tyre is the next best thing. The last thing you want is a tyre with an A/T or worse still an M/T tread that will just want to dig holes. Having said that, I and many others successfully run LT tyres with an A/T tread on sand but it's a compromise because we also need a tyre tough enough for rocky tracks. I recall how much better the Jeep went on sand with the stock Kumhos and with less airing down than my current tyres. With passenger tyres you will have optimal performance on both bitumen and sand... all you loose is the macho factor.
 
  • Like
Reactions: imaz and Brett
#299 · (Edited)
My standing recommendation for 20 inch light off road is 275/55/R 20 which is, +4% OD 810mm. For your spare can use a 255/70/R18: 814mm, like the
Bridgestone D840 H/T.

Extra sidewall will help you get a longer foot print on the sand.

4 mm difference in theory but the All terrains will have bigger tread pattern to reduce it.
 
  • Like
Reactions: Brett
#301 ·
Brett I run exactly what snake doctor recommends and I got a spare tyre off my dealer, it is second hand but still plenty of tread for a spare.


Hutch- 2014 GC Blackhawk CRD...Feel the Power...
 
  • Like
Reactions: Brett
#304 ·
My original Kumho had 65% tread left after 32,000 KMs. A nail in the sidewall of right rear tyre and a slight wear on left side of left front tyre (bad alignment) forced me to replace all four of them. Installed Nitto Terra Grappler 265/50r20 yesterday. $1,036 for four tyres balanced and installed plus $30 for front and rear alignment. They inflated the tyres to 3.1 (Bar) about 45 psi. What should be the optimal pressure for normal on road drive?
 
#306 ·
Thanks Snakedoctor, hutch801, Pharmaboy and BobT for your input.
BobT I tend to agree with your recommendation.

I've found the stock khumos really great on sand. One factor swaying me towards A/T is the durability. Even though I do mostly sand driving, I do encounter some tracks on Fraser where they are heavily rutted with lots of exposed tree roots. The delicateness of the khumos concerns me. Similarly there are areas of exposed coffee rock on the beaches which can be quite sharp. How much have you found your A/T's to dig down into the sand compared to stock?

Oh, and yeah you guessed it BobT, the macho factor of the A/T's is also a big influence?
 
#307 ·
Ah, broken tree roots on Fraser will poke through a stock Kumho like through wet toilet paper. Passenger A/T's won't help much with that either. You will need to go to an LT A/T. As I recall, much of Fraser driving is on the hard wet sand which should be no problem with A/T's. Personally, I like to stay on the dry to keep out of the salt in which case an extra 2psi of airing down may be required, say 16psi with A/T's whereas 18psi might do with passenger tyres. The problem is always crossing the fluffy wet stuff between the dry and the hard wet sand. This is where the A/T's can quickly dig in if you give it too much stick in an effort get out of there quickly.
 
#310 ·
The Nitto's go well on the sand, just not enough profile with the 20 inch wheel but I have never had any issues. In saying that i want to offroad more with confidence so I have some 285/60/18's going on tomorrow.
 
  • Like
Reactions: BobT
#311 · (Edited)
20" Tyre Thread




I've never had any issues with the stock 265/50/20 khumos and the low profile on the sand and I've worked them hard on every inch of Fraser and Moreton including all the difficult sections like ngkala rocks bypass. It's more a lack of confidence in how soft the khumos are. Plus the nittos look great. [Edit: but I get why you want 18s for more hardcore 4wd'ing!]

I'm likely to pull the trigger on the nitto 285/50/20 on Monday (heading for Fraser next weekend). The 275/55/20 are no longer available from what I can tell, so that makes the choice a little easier. Probably just going to keep the stock spare for now and if I get a flat it should get me back to civilisation with less than 3% difference in OD... I hope...
 
#313 ·
My last concern with the 285/50/20 is how close will they be to the upper control arm bolt Tire Auto part Automotive tire Automotive wheel system Pipe
? Attached shows the stock khumos, and they are pretty snug (about a thumb width).
I know others are running the 285/50/20 no problems, so just looking for some reassurance really... I guess when airing down for off-road the gap will get bigger too, so should be all good.
How close are your 275/55 Hutch?
Anyone else running 285/50/20?
 
#314 ·
My last concern with the 285/50/20 is how close will they be to the upper control arm bolt View attachment 63846 ? Attached shows the stock khumos, and they are pretty snug (about a thumb width).
I know others are running the 285/50/20 no problems, so just looking for some reassurance really... I guess when airing down for off-road the gap will get bigger too, so should be all good.
How close are your 275/55 Hutch?
Anyone else running 285/50/20?
Airing down will not affect the profile up high, only the contact patch. However, I share your concern about the clearance. The control arm you are referring to is the top of arm of the steering knuckle. They are not particularly strong. The steering knuckle is absolutely identical to a range of Chrysler vehicles so there is no particular allowance for off-roading. I've already bent one but not quite far enough to touch the tyre. BTW, by legislation, they are not allowed to be straightened so I had to get a new one. I bought it myself from the States and got a local trusted mechanic to fit it. Much much cheaper than getting Jeep to do it.
 
  • Like
Reactions: Brett
#315 · (Edited)
20" Tyre Thread

I just fitted the Bridgie 697 this morning, previously I could just get a finger between the tyre and the bolt with 275/55/20, with the 285/60/18 it actually has slightly more room, it will really depend on the tyre and how square the shoulder is. I have gone to 18 inch wheels not sure if they are slightly more offset any more, they are off a 2013 model.



Hutch- 2014 GC Blackhawk CRD...Feel the Power...
 
  • Like
Reactions: Brett
#317 · (Edited)
Re: 20" Tyre Thread

I just fitted the Bridgie 697 this morning, previously I could just get a finger between the tyre and the bolt with 275/55/20, with the 285/60/18 it actually has slightly more room, it will really depend on the tyre and how square the shoulder is. I have gone to 18 inch wheels not sure if they are slightly more offset any more, they are off a 2013 model.



Hutch- 2014 GC Blackhawk CRD...Feel the Power...
Hutch,
The Bridgie 697 285/60R18 is an LT tyre whereas your Kumho(?) 275/22/20 was a passenger tyre albeit an XL passenger tyre. LT tyres are relatively rigid and square whereas passenger tyres bulge more for comfort and performance. So while your 697's have a wider tread, the tyre is actually narrower. Better for off-roading. Those soft bulgy sidewalls on passenger tyres are so vulnerable to rocks. This is also why a stock sized passenger tyre won't fit into the spare tyre well whereas a stock sized LT will just fit... but forget trying to fit the 285's in. The XL refers to extra load. In all respects it is still just a passenger tyre but made slightly stronger in order to take high air pressures and therefore higher loads. Frankly I don't think XL tyres are worth it for the Jeep. The axle load capacity of the Jeep is not really high enough to take advantage of the extra load capacity of XL tyres.
 
#316 ·
Yeah good point BobT about airing down not affecting up high near the control arm...
In theory I reckon the gap between tyre and control arm on the 285/50/20 should be pretty much the same as with the 275/55/20 since the 285 is a bit wider, but the 275/55 is a bit higher. Hopefully that theory plays out, still a bit worried though.
Good to know you still had OK clearance with the 275/55 Hutch. Also good to know your 285/60/18 was all good, which in theory have slightly greater OD than 285/50/20.
 
#318 · (Edited)
20" Tyre Thread

Land vehicle Vehicle Car Sport utility vehicle Jeep grand cherokee

Had the 385/50/20 [edit: 285/50/20] terra grapplers fitted today. Looks great! Looks like a real "fourby" now. They are very quiet, do not bother me at all with windows down and radio off. Haven't had on freeway yet though.

The gap between the tyre and control arm bolt is a bit worrying. Probably a little less than 5mm - can't even fit the end of my pinkie finger in the gap! I guess it should be OK but am heading to Fraser this weekend and am freaking out to say the least...

Getting wheel alignment done by jeep tomorrow, so hopefully the gap gets no worse. Might have to consider some spacers when I get back?
 
#319 ·
Re: 20" Tyre Thread

View attachment 63994
Had the 385/50/20 [edit: 285/50/20] terra grapplers fitted today. Looks great! Looks like a real "fourby" now. They are very quiet, do not bother me at all with windows down and radio off. Haven't had on freeway yet though.

The gap between the tyre and control arm bolt is a bit worrying. Probably a little less than 5mm - can't even fit the end of my pinkie finger in the gap! I guess it should be OK but am heading to Fraser this weekend and am freaking out to say the least...

Getting wheel alignment done by jeep tomorrow, so hopefully the gap gets no worse. Might have to consider some spacers when I get back?
They look great - it looks like a Jeep now. Is there any rubbing?

I have QL and 275/55-20 Duratracs, and at Park height, full lock right, there is some rubbing, not a lot. It's noticeable in reverse, and not noticeable in forward. Parking lot speeds, less than 3 MPH. Also when I have four adults and driving at Aero height, on some bigger bumps I get a little rubbing at the left rear at the bottom of the suspension travel. After the bump there is no rubbing; only on the bumps, and only on bigger ones.
 
#326 ·
imaz,
I've got you on my watch list :moon: :)

Brett,
The wheel alignment won't affect the gap between the tyre the top of the steering knuckle. Be wary of having Jeep do the wheel alignment. Jeep wheel alignment tolerances are ridiculously wide. My guess is if the readings are anywhere within tolerance, they will do nothing and charge you for a full alignment. Better to go to a reputable wheel place and give them the specs. At least they will try to get as close to the preferred values as they can.

Regarding spacers, please don't use them. They are a great way to totally stuff up the suspension geometry not to mention over-stressing the wheel bearings. They are OK for temporary use as you ponce your way down the Concours d'Elegance or if you have after market wheels with a larger than stock negative offset.
 
  • Like
Reactions: Brett
#327 ·
Thanks Bob, you are a wealth of information.

Yeah I do want to avoid spacers. I am a little worried that when I air down that there may be some more slop at the top near the bolt, though I am really just being paranoid now since the gap is so much less than others have described. After driving around for the last couple of days I am gaining confidence.

Yeah I did try and get the tyre place to do the alignment but they refused due to the QL and told me to go to Jeep. And yes I did read the alignment report and you are spot on!

By the way for those interested I paid $369 per tyre at ktas. Most expensive quote I had was $489?
 
#328 ·
Spacers are illegal as well, their are plenty of people running 285's I have seen some tyres really close to the bolt but no issues. I can get my finger in mine some u would lucky to get a pen in between them.


Sent from my iPad using JeepGarage
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top