Has anyone upgraded gen 4 tyres without going bigger?

Busta wrote:

I have a set of brand new Gen4 wheels with the 195/80 Dunlop Grandtreks on I've never fitted. I have had a set of BFG 215/75 all terrains on my car for 5 years. Both sets are on standard steel rims. I'll swap them over and see what difference it actually makes.
 

I will be really interested in this comparison.  I am poised to buy a set of tyres for trials and had settled on 215/75r15, but they are out of stock with my local fitter.  The alternative is 195/80r15, which are roughly the same diameter but 20mm narrower, although if there is no difference in tread on the ground when you air down it does make sense to go for the lighter tyre.

The surface we have at our local trial varies, today it was mostly soil, some clay, some mud and the odd bit of concrete.  I ran in to loss of grip today on my Worm-Drives, but actually not as bad as I thought I would, so not sure if the narrower tyre would have been better or not?

Robin

Hello all, 

New here and also with similar dilemma as Bob.
Done some exploring of trails on stock dunlop at20 and planning to do a lot more in winter so looking to do some kind of tyre upgrade  soon (195s better tread or 215s), but do I need to?
I really like the comfort of the stock tires. I tried a Jimny with 215s and the wheels seem to crash more into speed bumps and large potholes. Their better for smaller bumps but at the cost of the larger bumps. The stock 195s just feel so much lighter for the suspension to deal with... 

My theory is that changing tyres will only give you confidence. Ie a Jimny has to try really hard to get stuck in any tyre combo. Like so far I have yet to reach Jimny limit (high limit) and when I do will the 215 goodrich save me? I am not sure. I see a big hole of mud  ahead I will take it in 215 goodrich because I know how capable the combo is but lowering the pressure and taking with speed on stock will probably achieve the same thing. Like was said in previous posts I have seen the yt videos in asian mud on stock tyres and Jimny just takes it and does the job. So what's the point of heavier, less economical, less comfortable tyres... (I know for many people its looks)

Bob you have 5dr and I have 3dr which is not direct comparison but how is the comfort over big pot holes? (I know you have the 195s but more aggressive pattern) 

Rant over (for now)

 

Kalinin wrote:

Hello all, 

New here and also with similar dilemma as Bob.
Done some exploring of trails on stock dunlop at20 and planning to do a lot more in winter so looking to do some kind of tyre upgrade  soon (195s better tread or 215s), but do I need to?
I really like the comfort of the stock tires. I tried a Jimny with 215s and the wheels seem to crash more into speed bumps and large potholes. Their better for smaller bumps but at the cost of the larger bumps. The stock 195s just feel so much lighter for the suspension to deal with... 

My theory is that changing tyres will only give you confidence. Ie a Jimny has to try really hard to get stuck in any tyre combo. Like so far I have yet to reach Jimny limit (high limit) and when I do will the 215 goodrich save me? I am not sure. I see a big hole of mud  ahead I will take it in 215 goodrich because I know how capable the combo is but lowering the pressure and taking with speed on stock will probably achieve the same thing. Like was said in previous posts I have seen the yt videos in asian mud on stock tyres and Jimny just takes it and does the job. So what's the point of heavier, less economical, less comfortable tyres... (I know for many people its looks)

Bob you have 5dr and I have 3dr which is not direct comparison but how is the comfort over big pot holes? (I know you have the 195s but more aggressive pattern) 

Rant over (for now)




 

Hi Kalinin, I see your issue. Although I honestly don't really agree with any of your assumptions or statements. I'm also fairly confident that the laws of physics also wouldn't agree with them.

The weight of a 195 vs a 215 must be marginal and is likely very dependant on the brand, tread and construction. You would have to be better than a Formula 1 driver to be able to truly notice the difference with all other things being equal. And even then I'm not sure you really could, considering the axles are only attached to the chassis via many large rubber bushes.

Tyres are likely more about price and availability. The Jimny is capable and traction control can let you do many things off road. But tyres are more than just that, you have different degrees of puncture resistance when off road. And when you need more traction, you can very quickly run out of grip with the wrong tyres.

Wet grass or mud are perfect examples where road or even AT's can run out of traction very quickly. Also traction control cannot prevent a vehicle sliding sideways, that is all about the physical grip of the tyres on the surface.

Therefore it comes down to what you really want from the vehicle. A stronger, tougher tyre like an AT or MT will be heavier than a road biased tyre. And will have more impact on ride & handling. Bigger taller tyres may have more sidewall to absorb more bumps too.

Personally I think the suspension is the issue. The stock setup is 'ok', but can be massively improved with better dampers. I'm currently running 235/75's in an All Terrain pattern and a 2" lift and the Jimny rides and handles way better than it ever did with stock tyres and suspension.

BFGoodrich are also not the be all and end all in tyres either. Nothing wrong with them, but there are many good tyre brands out there. BFG also offer a variety of tread patterns. Not all will work the best on all terrains. And believing "I see a big hole of mud  ahead I will take it in 215 goodrich because I know how capable the combo is but lowering the pressure and taking with speed on stock will probably achieve the same thing." is likely just misleading yourself that could end in tears off road.

Not sure what country you are in or what kind of terrain you will be driving on. But I'd take a look and see what types and brands of tyres are available in the different sizes and make an informed decision from there on which offers the best value for money while being suitable for your intended use.

300bhpton wrote:

The weight of a 195 vs a 215 must be marginal and is likely very dependant on the brand, tread and construction. You would have to be better than a Formula 1 driver to be able to truly notice the difference with all other things being equal. 

You might be surprised.  The factory tyres are quite light, about 10.4 kg each.  BFG KO2 in 215 is 14.5 kg, 40% heavier than standard.  BFG mud tyres in 215 -- 18.1 kg, 75% more than standard.

I have a set of winter tyres/wheels, like most people where I live.  The difference to the standard 195 Dunlops and steelies is about 3kg per corner, and the change is very noticeable.

Other than that, no disagreement with what you wrote.  And personally I think BFGs are vastly overrated and rather inferior tyres.  Not sure why anyone in the UK would run them, as I hear it rains there sometimes and most BFG patterns are lethal in the wet.

Motacilla wrote:

You might be surprised.  The factory tyres are quite light, about 10.4 kg each.  BFG KO2 in 215 is 14.5 kg, 40% heavier than standard.  BFG mud tyres in 215 -- 18.1 kg, 75% more than standard.

I have a set of winter tyres/wheels, like most people where I live.  The difference to the standard 195 Dunlops and steelies is about 3kg per corner, and the change is very noticeable.

Yes indeed, AT and MT will weigh more than a road biased tyre.

A 195/80R15 MT will likely weigh more than a 215/75R15 road tyre. The size difference just isn't all that great and tyres vary a lot in terms of physical size, even when rated and sold as a said size. BFG KM3's have quite a narrow section width, i.e. not as wide as the sidewall or bead area. But other tyres can have a very different tread design that can make them much wider as a section width, even when rated as the same size.

Easy answer is same size with more tread. The difficult answer is in the rest of this thread.