Largest Functional Tire Without Mods

[d1rty]

I"m a fan of the pizza cutter style. 255/80-17 is just over 33" tall, depending on tire. But nice and skinny (and theoretically, lighter, again will vary by tire). I think this will be my move either when the KO2s wear down, or I get bored.

 

[stickshifter]

Hi folks,

A quick search on the forum pulled up three pre-existing threads on tires. Maybe we try to consolidate?

General question about tire dimensions

I have read about 35" tires and don't understand the numbers. Here in Germany, we have e.g. 17" tires in the Grenadier configurator. Seems, that tire dimensions use different measures in the USA and in Germany. Can somebody shed some light on this?

www.theineosforum.com

https://www.theineosforum.com/threads/35-tyres.12391811/#post-1333123550

https://www.theineosforum.com/threads/largest-functional-tire-without-mods.12371337/

 

[AnD3rew]

You don’t need engineers certifications for all tyre size changes only outside of certain parameters, you would need to look them up, but I think in NSW you can go about 2” taller without certifications, you also need to stay inside guards etc. we will only really know when someone tries and I predict someone will try pretty soon, but I think going to 33” is likely to be very acheivable without any drama or other mods.

 

[Stu_Barnes]

Hi folks,

A quick search on the forum pulled up three pre-existing threads on tires. Maybe we try to consolidate?

General question about tire dimensions

I have read about 35" tires and don't understand the numbers. Here in Germany, we have e.g. 17" tires in the Grenadier configurator. Seems, that tire dimensions use different measures in the USA and in Germany. Can somebody shed some light on this?

www.theineosforum.com

https://www.theineosforum.com/threads/35-tyres.12391811/#post-1333123550

https://www.theineosforum.com/threads/largest-functional-tire-without-mods.12371337/

Thanks for picking this up @stickshifter

Threads merged.

 

[Deleted User Account.]

[QUOTE username=Ferrugenfish userid=9004165 postid=1332800035]Okay so it's good to know that "minor trimming" is required to fit 35's... ground clearance is not impressive and needs a little help. It sounds like one would need to upgrade the springs/dampers and probably control arms and give it a decent lift in order to fit 35's to fit without cutting in order to get both increased travel and ground clearance.... which is a shame. IMO, Ineos should have expected people to want to fit 35's... but hey, 33's don't suck, and as noted above, 35's might not even fit on the rear door anyway. Looking forward to someone trying all of this and finding the best solution to maximizing ground clearance without screwing up articulation/geometry.

In all honesty, INEOS hasn't built this as a bronco/wrangler competitor. 35s are not needed for any workplace, overland trip, or other utility usage. The only place where big tires are NEEDED, are arctic expeditions etc. I had a wrangler on 35s, it looked great, but realistically never needed anymore than 33s to go anywhere.

35s with a small lift etc is still better than most other 4x4s. but ill be sticking with 33s on mine!
[/QUOTE]

I agree in principal. Totally unnecessary, but I run 37s on my truck and there are a few advantages. A small lift and those tires make it incredibly easy to work under the vehicle without needing to jack it up, which also translates off road. I've gotten great traction when off road (except on loose sand). Lastly, the massive lugs have kept me from getting a flat tire over the 250,000 miles I've driven with them on. I've just not encountered any kind of highway debris long and sharp enough to make its way through them.

 

[stickshifter]

Thanks for picking this up @stickshifter

Threads merged.

You are a champion!

 

[stickshifter]

A lot of emphasis here on looks vs. performance. In the NE USA I had some scary results with extra wide tires on an old Suburban I used for fishing and hunting: coming down hill on an unplowed dirt road turned into a pure tobogganing exercise with no control over the path other that provided by the sides of the ruts. I went out and got a proper pair of snow tires that were appropriately narrow.

The LR IIA I bought used had super big, mongo tread mud tires on it, and on my first trip on the beach to go fishing, it immediately buried itself to the frame. Super aggressive tread and soft sand do not mix in my experience.

I remember an article in the 1970s about a Vermont Land Rover nut who would regularly challenge Jeeps to a hill climb race in the snow. They would flounder with their wide aggressive tread tires as he climbed ahead up the hill with narrow tires and chains, he would pull out the manual throttle control (remember them?) and step out, stand with crossed arms next to his old Rover that continued to climb by itself, and watch the struggling Jeeps below him, before walking back up to his Rover, climbing in and finishing the climb.

I do not have any experience in rock and mud scrambling, and I'm sure there are situations where super big tires are a must. But for the uses I have put my 4X4s to over the years on sand, dirt tracks, forests and highways, super wide and huge treads have not played well for me.

Fully agree. In the winter, a tall skinny tire is best for on-road driving. A tall wide tire is only good if you are off-roading in deep snow, and want flotation.

Going up in tire size (more than an inch or so) is a dance with the devil. You really have to know what you are getting into, or things can get problematic.

(1) Going from stock on the Grenadier (31.6 inches tall) to anything over a 33 really requires re-gearing, or you just aren't driving the vehicle you were sold (the power band of the engine is tuned to the transmission gears, and to the stock tire size). Re-gearing is expensive, and sometimes problematic if the gears aren't set-up right. Even with a good install, the new gears require a break-in period (You drive 15-20 miles, then let the gears cool down for 30-60 minutes. Repeat 5 times. Do not drive over 55 mph during this period). Lastly - with regard to re-gearing - we do not yet know if there even are alternate gear sets for the Carraro axles. Stock gears in the Grenadier are 4.10 to 1 (written 4.1:1). Go up to a 35-inch tire and you will need 4.56:1 (at least using common gear sets found in Dana axles - I don't know what the options would be for Carraro).

In addition, if you go up to a 35-inch tire, you will feel the mass: slower acceleration, longer stopping distance, and a tendency for the tires to follow road irregularities. In addition, you will get rubbing on steering components or on the inner fenders (unless the vehicle was designed to accommodate large tires, like the Wrangler). So a suspension lift will probably be necessary. There will likely be aftermarket suspension lifts for the Grenadier, but now you are getting into altering the factory-designed geometry of the suspension. The front control arms are pretty short on the Grenadier, so the vehicle will not likely handle very well with a lift, so then you might need a long-arm kit, which requires removing the mounts from the frame for the existing control arms (does this void the rust-proof warranty on the frame?), welding on new mounts, and then getting someone to fabricate long-arms (until a kit is developed). This will be a massive hassle until the aftermarket really dials it in, and even then, who knows?

With some vehicles, you need to beef-up the front steering components, like the track bar, tie rod, drag link, and ball joints. It sure looks like the Grenadier has a very stout front end, so this work can probably be avoided.

You've got to really need a tire this size for a purpose to take on these drawbacks. Doing it just for looks seems like a bad choice - unless you've got the money and time to throw at it.

 

[chriscroft]

If the Grenadier is being supplied into South Africa with 35" tyres as OEM, I guess we'll find out what Ineos think will need to be different.

I don't think 35" will be for me; but the Grenadier has been tested in Death Valley and others towing 3500kg and fully loaded, plus some, (I think I've read it has been tested with a 200% payload in some trails) with professional drivers trying to stress the vehicle to breaking point.
For my use, I will never get close to these stress levels, so I don't think the gearing would be an issue..to me...maybe.

 

[stickshifter]

If the Grenadier is being supplied into South Africa with 35" tyres as OEM, I guess we'll find out what Ineos think will need to be different.

I don't think 35" will be for me; but the Grenadier has been tested in Death Valley and others towing 3500kg and fully loaded, plus some, (I think I've read it has been tested with a 200% payload in some trails) with professional drivers trying to stress the vehicle to breaking point.
For my use, I will never get close to these stress levels, so I don't think the gearing would be an issue..to me...maybe.

I really want to hear more from Ineos about this. Where are the results of these tests? To be honest, I think they are falling short on their communication with regard to this issue, but maybe I just need to be patient.

Regardless of what Ineos designed the vehicle for, there will definitely be people in North America who cross-shop the Grenadier against the Wrangler and Bronco, and they will want more info about the potential for up-sizing the tires.

 

[AnD3rew]

I really want to hear more from Ineos about this. Where are the results of these tests? To be honest, I think they are falling short on their communication with regard to this issue, but maybe I just need to be patient.

Regardless of what Ineos designed the vehicle for, there will definitely be people in North America who cross-shop the Grenadier against the Wrangler and Bronco, and they will want more info about the potential for up-sizing the tires.

I have seen no indication that INEOS will be supplying in any markets with anything other than the stock size tyres. They definitely played with 35” and it would be nice if they gave us some official information on what they found and how they did it, but I very much doubt that will be forthcoming.

 

[Tazzieman]

The competent driver on 31s who outperforms the guy with 37s....

 

[stickshifter]

The competent driver on 31s who outperforms the guy with 37s....

What happens when you get a competent driver on 37s?

 

[Tazzieman]

What happens when you get a competent driver on 37s?

He doesn't spin the wheels and ruin the track for everybody else.
Not talking dry rock here.

 

[Lancs Lad]

I'm told...there's a picture of one running 35's as a support vehicle for the BMW bikes...but i cant find it.

Obviously you've got the rear door issue...

 

[stickshifter]

Two shots on 35s from Iceland, one from South Africa, and one from Namibia:

 

[Tom D]

It does look the part with 35’s… not sure I could put up with the road manners though. I’m going 33’s..

 

[PanoramaJJ]

It does look the part with 35’s… not sure I could put up with the road manners though. I’m going 33’s..

What about a Grenadier on 37´´s? plus a 5´´ Liftkit?

 

[AZGrenadier]

What about a Grenadier on 37´´s? plus a 5´´ Liftkit?

Didn’t you see the thread with the portals

 

[AnD3rew]

It does look the part with 35’s… not sure I could put up with the road manners though. I’m going 33’s..

Yep, certainly not doing a lift, at least not until quite a few others have done them and run them for a while and ironed out the kinks and learned the tricks. When my KO2s are worn out I will probably look at going up a tyre size to around 33” but also hope to hear about other’s experiences doing that first to see if they get any rubbing or performance issues.

 

[AZGrenadier]

Yep, certainly not doing a lift, at least not until quite a few others have dine them and run them for a while and ironed out the kinks and learned the tricks. When my KO2s are worn out I will
Probably look at going up a tyre size to around 33” but also hope to hear about other’s experiences doing that first to see if they get any rubbing or performance issues.

That is my plan as well.