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Fitted 215 75 15 KO2 tyres thought this would make a big impact "but no". Fuel filter & TC case guards fitted still OK.
I like your new front bumper but 35/40Kg isn't going to help. As i drive on road most of the time tyre pressure is 29/30psi any lower and they look flat (MY CHOICE) fuel consumption is 39.6 mpg. Keep it light.
Fairly early on I changed to 215/75r15 tires. Based on all that I read on the forum, and without other modifications, I had expected no notable difference on highway performance.
I don't know what transmission you have but my Jimny with an auto behaved much like you described. The final drive ratio is a bit different between the AT and MT. What I noticed wasn't enough to make me grind my teeth but it was recognizable. I could really tell the difference when driving an incline on one of the mountain highways. The good thing is that I didn't really notice a difference off-road.
If you do have an auto transmission, the only thing I can add is that you will get used to it.
Edit: As far as the transfer case goes, if they put the wrong case in (AT vs MT) the gearing difference would be far more noticeable than what you are describing.
I started out with nothing & still have most of it left
We are on 215/75 R15 KM3 and think the Jimny drives just fine.
Jimnys have always needed the revs keeping up to keep it bowling down the road and the gen4 is no exception. Diesel 4x4 do all their power at low revs and most do not even rev to the point you have to get to before the Jimny engine starts to produce it's power.
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Martin
2003 M13 early KAP build.
3" Trailmaster lift with 1.5 Spacers on front
Customised winch bumper and roll cage
235/85R16 Maxxis Bighorns on 16" Rims, 4:1 Rocklobster, Rear ARB locker and on-board air
Corrected arms all-round, rear disks, Recaro seats and harnesses
I weighed my 215/75r15 BFGs and they are 5kg heavier than the standard Bridgestone Duellers on my gen 3. Adding 20kg of rotating mass is not insignificant!
The increase in circumference might only be 1.5% but the affect of any change is compounded if the speedometer is not adjusted accordingly. Effectively you have 1.5% longer gearing, and are trying to achieve 1.5% higher speeds.
I recently changed my diffs from 3.9 to 4.1 which putts the gearing close to standard and It makes the Jimny seem much more sprightly. Still not the same as it was on standard size lightweight road tyres, but an improvement nonetheless.
Roger Fairclough wrote: This is to be expected. You are now running with wider tyres so your footprint is bigger and that will create more drag. Add to that you have changed the gearing and cumulatively you have dented performance and increased fuel consumption. On my Landcruiser in standard trim 50-70 mph in 5th gear was 10 seconds. Change to A/T tyres and it went to 13 seconds. change again to M/T in 33" dia as apposed to 31" and it went to 16 seconds. Also adding lots of extras will make things worse. The Jimny is a lightweight motor and cannot cope with all the gear that my landcruiser could lug around.
Roger
Don't get me wrong. I understand where you are coming from. I'm very used to swapping wheels and tyres. We have an entire shed full of Land Rover tyres on the farm.
What I am surprised at, is the impact on the performance. Compared to other 4x4's I've owned/driven.
Especially considering the fact I haven't really changed the wheel size all that much on the Jimny.
Andy2640 wrote:
I may be wrong, but havnt you also fitted some under plate protection recently too??
Ive lost a bit of zip too with 215/70/16's, but im still happy with performance.
Ive never understood folks who thinknthe jimny is slow, nor with cornering lean. I musr be a bit of a grandpa behind the wheel or something.
No under body protection.
It does have tree sliders, diff guards and a winch bumper. BUT.... it ran fine with all of these fitted. You'd not really know they were there. And to be fair, added up, they weigh less than an average person. And by quite a bit I should imagine. So are less noticeable than having a passenger. And it has always gone fine 2 up in that guise too.
The only changes were:
- new transfer box
- some days later (maybe a week) the tyre swap
And it was directly after the tyre swap, like hitting a light switch that the performance suffered hugely.
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