Biggest legal tire size for a disco 4

[Miffy]

Hi there,

I'm considering changing my rims for my Disco 4 to take a larger size tire. Does anyone know what is the largest legal rim and tire size allowable. Also need to consider that tires will not rub against anything when 4WDing and wheels articulate.

Thanks

[discomatt69]

I run 265 65 18, equates to 32 inch, they just rub on full compression in the rear but it only just touches the plastic inner guard so no issue

[Tony V]

Miffy,

I run 20" wheels with 275x55r on my D4 31.9"

The front can rub under compression, but very little.

[Laurie 123]

I run 265 65 18, equates to 32 inch, they just rub on full compression in the rear but it only just touches the plastic inner guard so no issue


265/65/r18 are actually 31's 275/65/18 are 32's

[discomatt69]

265/65/r18 are actually 31's 275/65/18 are 32's

31.6 if you want to split hairs so closer to 32 than 31[bigwhistle]
275/65/18 is 32.1 so technically 2.1 bigger than standard and therefore technically 0.1 bigger than the legal size increase, the thread is after all named Biggest LEGAL tire size

[scarry]

And splitting hairs,different tyre brands have slightly different measured sizes,for the same size tyre,if you know what i mean.

[Laurie 123]

31.6 if you want to split hairs so closer to 32 than 31[bigwhistle]
275/65/18 is 32.1 so technically 2.1 bigger than standard and therefore technically 0.1 bigger than the legal size increase, the thread is after all named Biggest LEGAL tire size


Well ok but that's the size Johnson rods site recommends for Disco 3 so maybe they are wrong to sell these with that quote ?? So what size would you recommend that is exactly 32" cos i am right in the process of buying JR 's with the idea of fitting 32" ie; 275/65/r18 ? Cheers

[Turtle60]

Well ok but that's the size Johnson rods site recommends for Disco 3 so maybe they are wrong to sell these with that quote ?? So what size would you recommend that is exactly 32" cos i am right in the process of buying JR 's with the idea of fitting 32" ie; 275/65/r18 ? Cheers
Just curious why so big. You must have a rear tyre rack as my 265 65 18 has to be stored deflated. 275 is no chance underneath. Horses for courses though. The actual tyre specs on there website will show overall rolling diameter and they do vary a tad for the same size. The standard size of 255 55 19 = 763mm therefore Max = 813mm rolling diameter. 275 = 814mm but you may crack a brand that’s less. 265 = 804., speedo perfect, Look them up. Good luck

[Laurie 123]

Just curious why so big. You must have a rear tyre rack as my 265 65 18 has to be stored deflated. 275 is no chance underneath. Horses for courses though. The actual tyre specs on there website will show overall rolling diameter and they do vary a tad for the same size. The standard size of 255 55 19 = 763mm therefore Max = 813mm rolling diameter. 275 = 814mm but you may crack a brand that’s less. 265 = 804., speedo perfect, Look them up. Good luck

Do you think 32 are too big ? other than you can't store them i was looking at the roof hehe
I have 255/65 r18's at the mo maybe these would do ?Would save me a few bob !

[Turtle60]

Do you think 32 are too big ? other than you can't store them i was looking at the roof hehe
I have 265/65 r18's at the maybe these would do ?Would save me a few bob !

Tyre size and brand is a can of worms. I can only say what I run are 265 65 18 kO2’s and feel bullet proof in them. I’m guessing ( and I don’t do this) 275’s may be an advantage for mud rrunning hill climb events. For everyday day touring / dirt roads I believe all round it is overkill and a pain in the proverbial and actually illegal. But yes my 265’s are stored deflated underneath and there may occasionally rub but rarely. 265 60 18 wont do any of the above but are hardly bigger than standard. Cheers

[LRD414]

Johnson Rods are an American product so not the best source for info on Aus rules. It would be worth understanding what is legal in your state. Having your spare on the roof all the time doesn’t seem like a great idea and doesn’t leave much capacity for carrying anything else. You should also research the wheel arch and possibly chassis mods required if running the 275/65, plenty of info on that in here if you search.

I have been using 265/60 KO2s for awhile now and find this size offers decent extra diameter and sidewall height without any rubbing or difficulties with the spare, as well as a good selection of tyres.

Scott

[Laurie 123]

Tyre size and brand is a can of worms. I can only say what I run are 265 65 18 kO2’s and feel bullet proof in them. I’m guessing ( and I don’t do this) 275’s may be an advantage for mud rrunning hill climb events. For everyday day touring / dirt roads I believe all round it is overkill and a pain in the proverbial and actually illegal. But yes my 265’s are stored deflated underneath and there may occasionally rub but rarely. 265 60 18 wont do any of the above but are hardly bigger than standard. Cheers


Thanks Turtle! yep the ones i have are probably ok But ruts are a bit of a prob thats why im instaling JR's In saying that i might try what you recommend and are running on your rig .Thanks mate !

[Laurie 123]

Johnson Rods are an American product so not the best source for info on Aus rules. It would be worth understanding what is legal in your state. Having your spare on the roof all the time doesn’t seem like a great idea and doesn’t leave much capacity for carrying anything else. You should also research the wheel arch and possibly chassis mods required if running the 275/65, plenty of info on that in here if you search.

I have been using 265/60 KO2s for awhile now and find this size offers decent extra diameter and sidewall height without any rubbing or difficulties with the spare, as well as a good selection of tyres.

Scott


Yep the tires you are using 265/60 ko2's are the same as Turtle60 uses so i will definately have a crack at them seems most of the blokes are using that size with great results Thanks mate

[LRD414]

Yep the tires you are using 265/60 ko2's are the same as Turtle60 uses so i will definately have a crack at them seems most of the blokes are using that size with great results Thanks mate

He stated 265/65 and mine are 265/60. Both are quite popular for the D4 but the 265/60 meets the original OP query; legal and zero rubbing.

Scott

[Laurie 123]

He stated 265/65 and mine are 265/60. Both are quite popular for the D4 but the 265/60 meets the original OP query; legal and zero rubbing.

Scott


Roger that !! Thanks

[discomatt69]

I have a rear wheel carrier so the size isn't a issue for storage, from my experience wider is not better but the taller the better,hence the reason I went 265/65 not 265/60. Both sizes have pros and cons, both are readily available and easy to get

[Redback]

I have a rear wheel carrier so the size isn't a issue for storage, from my experience wider is not better but the taller the better,hence the reason I went 265/65 not 265/60. Both sizes have pros and cons, both are readily available and easy to get

While this maybe the case in the city of even rural NSW VIC, the NT is very different, rural areas up there still haven't quite got a grip on 17",18" and especially 19" tyres in certain sizes and it can take time to get them in if you happen to get a flat need a new one.

So if you want to put larger tyres on a D4 don't pick an obscure size, go with a common size even if it means it's not larger for remote travel.

Just out of interest Laurie123, is your D4 a 2.7l, if it is go with 17s if you can.

[Melbourne Park]

Tyre size and brand is a can of worms. I can only say what I run are 265 65 18 kO2’s and feel bullet proof in them. I’m guessing ( and I don’t do this) 275’s may be an advantage for mud rrunning hill climb events. For everyday day touring / dirt roads I believe all round it is overkill and a pain in the proverbial and actually illegal. But yes my 265’s are stored deflated underneath and there may occasionally rub but rarely. 265 60 18 wont do any of the above but are hardly bigger than standard. Cheers

The interesting thing about the 265/65/18 is that they cost the same as the same BFG kO2 265/60/18. There is more cost in the 65 sidewall versus the 60's sideway because the 65 is taller, but they cost much the same - my quote is less than $2.00 difference.

Curiously with the BFG tyres, their 265/65/18 is not really IMO a 65 tyre - because its diameter is 801mm (legal as Wrangler that ships with D4s are 255/19/55s with a diameter of 763, hence add 50mm you get 813mm max legal in most states I think. The BFG 275/65/18 is 815mm Diameter whence marginally illegal IMO. Note too the ratings go from the standard tyre of 240KMH, to much lower with the kO2 BFG - the 65 profile is not much over 160 KMH.

Some figures for the Standard tyre on the D4 2014, and from BFG's KOs tech sheets:

original Discovery Tyres


763 OD


WRANGLER HP ALL WEATHER
SUV Highway


So add 50 to 763: 813 OD Maximum;


Original Wranger Goodyear Discovery Tyres


Front Size




SKU

542929


Application

SUV Highway


Section Width
255


Aspect Ratio
55


Rim

19


Construction
SUV HIGHWAY


Load Index

111 { represents load carrying capacity: 1090 kg }


Speed Rating
V { represents max speed capability: 240 km/h }


Side Wall Lettering
BLT


Nominal Od

763


Radial Diagonal
R


Ply Rating

XL


Tube Type

TL



BF Goodrich KO2 tyres:


]275/65R18 123R


Display Rim
18
Overall Diameter
815 - therefore 2mm too large
Width
275
Aspect Ratio
65
Rim Size
18
Load Index
123
Speed Index
R


Display Rim
18
Overall Diameter
801 - Therefor quite legal
Width
265
Aspect Ratio
65
Rim Size
18
Load Index
122
Speed Index
R


265/60R18 119S


Display Rim
18
Overall Diameter
775
Width
265
Aspect Ratio
60
Rim Size
18
Load Index
119
Speed Index
S


I would have to deflate the under car tyre too if its 65 profile including for the 265/675/18 as well I think. And I need to ensure too that my about to be fitted bullbar from ARB will not hit 265/65/18s. I think wider than 265 would hit I have read ... on my still under warranty 2014 "Discovery" on the bonnet series D4 HSE.

The problem is that laso the 275 is not quite legal in Victoria in theory. So no insurance I guess. Not sure about warranty issues either. One would have to clear some issues or put in Llam or similar to not have clearance issues too.

By the way Green Oval who invented the Compomotive 18" tyre have a spreadsheet with all the tyres that fit without rubbing, some that rub a bit and some that rub more, and what to do about it. Worth downloading the spreadsheet IMO.

[discomatt69]

While this maybe the case in the city of even rural NSW VIC, the NT is very different, rural areas up there still haven't quite got a grip on 17",18" and especially 19" tyres in certain sizes and it can take time to get them in if you happen to get a flat need a new one.

So if you want to put larger tyres on a D4 don't pick an obscure size, go with a common size even if it means it's not larger for remote travel.

Just out of interest Laurie123, is your D4 a 2.7l, if it is go with 17s if you can.

Thats why I always carry 2 spares when going really remote, touch wood I have never needed 1 spare and the plug kit is also always close at hand.
Before our Kimberly trip last year that took us right across the top end I rang a few places before we left and they all said the bigger tires are becomming more common and are available if not that day with 2 days as now Prado and 200's run 18's

[scarry]

The 265/60/18 is the OEM size for some Prado and Pajero models,and quite a few utes.

[apom]

I have just starting running the Hercules Terra Trac II AT2 LT265/65R18 122/119 Load Index tyre.

Hercules Tires (https://www.herculestire.com/tire-details/Hercules/Terra-Trac-AT-II)

So far only around town use but super quiet, good road holding and NO RUBBING at any height or full lock. Less than $300 each fitted and balanced.

Spare fitted underneath but did need to be deflated. On the website they list them as 801mm (31.54inch) and the speedo is now spot on with GPS speed checking at every speed test so far.

Keen to give them a test in a couple of weeks and give some feedback

They also list a 275 (32.09) and 285 (32.56) in 65 series for 18" wheels on the USA site, suitable for our D5 friends

[Melbourne Park]

I have just starting running the Hercules Terra Trac II AT2 LT265/65R18 122/119 Load Index tyre.

Hercules Tires (https://www.herculestire.com/tire-details/Hercules/Terra-Trac-AT-II)

So far only around town use but super quiet, good road holding and NO RUBBING at any height or full lock. Less than $300 each fitted and balanced.

Spare fitted underneath but did need to be deflated. On the website they list them as 801mm (31.54inch) and the speedo is now spot on with GPS speed checking at every speed test so far.

Keen to give them a test in a couple of weeks and give some feedback

...

I'll check 'em out.

Costco quoted my $306 for 265/60 Dueler (Bridgsetone) tyres; and $362 for BFG Ko2 265/60/18 , and $364 for the BFG Ko2 265/65/18. The 65 seems much better value compared to the 60.

I have also thought that I could always put a smaller tyre under the Disco, with air in it. My 2014 Disco disco does not have a locking diff. With a locking rear diff, a different diameter tyre would be somewhat of a problem. But I cannot see a problem with the standard Disco's floating rear diff. I could put the punctured 265/65/18 onto the roof as well. Probably a less dirty job than crawling under the Disco. I have had a 6th tyre on the roof. I don't need anything else up there, but there's room for a 2nd tyre.

[Spence]

275/65r18 fits deflated no problems. Don’t need to remove heat shield. Don’t need to grind tow thingie (nitto ridge grapplers)