215 / 75 /15 AT tyres

I know this has been done to death but. On a Gen 4 how much on road prefrmance is lost by fitting these tyres. Took my Jimny off road today on a pig farm I was inpressed with it's performce on stock tyres although I did take some easy routes through the farm. If I had decent AT tyres I would have gone to more difficult area of the farm, By the way I was there to shoot crows not just to drive round the fields.
 

Very little. They are only 1.5% bigger circumference than the standard 195/80r15 tyres.

I'll say it depends. You can go for relatively light toyo open country at's to really heavy bfg km3 mt which are 6kg heavier for each tyre.
That rotating mass slows the acceleration and hinders braking.

crash486 JB74W

Interests me that it seems to be the accepted wisdom that wider tyres equal better traction. I run standard size mud terrains for trialling, my old boss had a hilux on wide tyres some years ago, was always getting stuck because not enough weight in the truck to get traction down. Young guy in our club with a jimny on wide tyres was struggling for grip on wet grass in a trial, narrow tyres sometimes get in the ground better.
I drive dumpers and they don't have particularly wide tyres when you consider their weight.
Then again, wide tyres look cooler....

Groundworker wrote: Then again, wide tyres look cooler....

There's your answer! And there's not much choice in taller narrow tyres these days. 215s aren't a wide tyre, but certainly wide enough for a Jimny.

Groundworker wrote: Interests me that it seems to be the accepted wisdom that wider tyres equal better traction. I run standard size mud terrains for trialling, my old boss had a hilux on wide tyres some years ago, was always getting stuck because not enough weight in the truck to get traction down. Young guy in our club with a jimny on wide tyres was struggling for grip on wet grass in a trial, narrow tyres sometimes get in the ground better.
I drive dumpers and they don't have particularly wide tyres when you consider their weight.
Then again, wide tyres look cooler....

I think it depends on the terrain and exact tyres. Sometimes wide tyres work very well. But as a rule I've found most places I've been in the UK, that narrow tyres work better off road.

That said, 215 is pretty skinny compared to some of the tyres I've got!

Agree, just op seemed to be talking about wet muddy conditions. Years ago I used to trial and SJ413 which I'd gone and bought some pretty wide tyres, they weren't great until we trialled at Bovington which is sandy and they came into their own. Americans love huge tyres but they do a lot of rock crawling it seems. Trialling 20 odd years ago, there was very limited tyre choice and most Suzuki's used Firestone SAT, 6.50x16 on LJ80 rims and Land Rover s ran 7.50x 16.

Gilling Red wrote: I know this has been done to death but. On a Gen 4 how much on road prefrmance is lost by fitting these tyres. Took my Jimny off road today on a pig farm I was inpressed with it's performce on stock tyres although I did take some easy routes through the farm. If I had decent AT tyres I would have gone to more difficult area of the farm, By the way I was there to shoot crows not just to drive round the fields.

 

Personally I thought it was quite noticeable.

The stock tyres I thought went ok overall. Will get you a lot of places and work well overall. But I wanted to change partly for the 'look' and to give a bit more clearance, as the Jimn is a little low and will catch underneath quite easily.

I also wanted something a little more mud biased. Ideally I think I'd have gone KM3's. But I was commuting quite a lot when I got my Jimny, so I opted for a set of All Terrains. BFG KO2 were on the list, but decided to go with the Maxxis Wormdrive AT's. Which are of similar ilk but worked out substantially cheaper. 5 tyres for less than 4 BFG's.

The tyres are wider and heavier. They should also be slightly taller, however this seems to be marginal.

Fitting them it was instantly noticeable in less pep. The car still runs well and I suspect against the stopwatch it might not actually be significantly different. But it did feel like it made an impact. I did have a winch bumper already fitted. So maybe it was a compound effect, but the tyres were noticeable to me. In fact, I struggle to understand how people say they couldn't feel a difference.

Has this mean enough to consider swapping back to the stock size? No I don't think so. The tyres have impressed off road and on.

I would say I also noticed a dip in mpg.

Personally I'm not sure how people are getting over 40mpg unless they are sitting at 50mph on dual carriage way. Before any mods and when commuting and running the engine in I was getting 39.2mpg +- 0.5mpg

This did dip once into lockdown and I stopped commuting and doing only shorter journeys. As of now I'm getting in the region of 33-34mpg. Even a gentle jaunt to Eastnor Castle with resetting the trip when setting off resulted in 34mpg.

Again, this wouldn't make me change back.

However I would not go any bigger with stock power and gearing. 235/75's must really blunt the performance and probably ruin the crawl speed in low 1st.


BTW - I'm not adverse to running big Mud Terrains. I had some very aggressive Simex tyres on my Discovery that measured 34" tall.

Groundworker wrote: Agree, just op seemed to be talking about wet muddy conditions. Years ago I used to trial and SJ413 which I'd gone and bought some pretty wide tyres, they weren't great until we trialled at Bovington which is sandy and they came into their own. Americans love huge tyres but they do a lot of rock crawling it seems. Trialling 20 odd years ago, there was very limited tyre choice and most Suzuki's used Firestone SAT, 6.50x16 on LJ80 rims and Land Rover s ran 7.50x 16.

Thought you'd said Bovingdon for a moment there. I'm sure that place isn't sandy...

We were more XCL than SAT. I still trial although not so frequent currently. I like to run some 7.00 x 16's for trails. Although I also have some 285/75's and 33.10.50's. This was for my Land Rover.

Although some of the best tyres I've used off road for traction where these, Simex Jungle Trekker II's in 33.11.50R15



Arguably a bit wide for some trials gates though.

 

Bovvy is definitely sandy! In Dorset near the tank museum, use it for tank training, don't think they let trialling there anymore. They let us use the tank wash to clean vehicles once, basically fire hoses, brilliant fun. Liquid sand used to get in your brake drums and wear your shoes out on the way home 

My old 413 on 6.00x16 SATs

I appreciate I mentioned this to Lambert on another thread, but I have checked again today and am seeing very limited options for 195/80 15 tyres. Is this off the back of the coronavirus pandemic limiting production of non mainstream sizes?

195 80 15 are pretty limited 
Plenty retreads availabe 
I've used hankook dynapro rf10 at 
a good tyre IMO