Gen4 offroad modification

Just out of interest what pressure do you have in the tyres? And more importantly have you checked it yourself rather than relying on what you asked the fitter set them to? I have had new tyres come back at 45psi plus in the past, they spin for fun. I know I'm labouring the point but the physics doesn't add up, you have a tyre with a larger contact patch which increases the available traction and you simultaneously have a taller ok not much but still, tyre that effectively decreases the torque that can be applied, which combined should be making it harder to spin the wheel not easier unless the tyre is some how contaminated, defective or over inflated. If I have for some reason got to retrieve a full trailer of sheep from my satellite location and then travel further than base I prefer to have my tyres set to full load pressure to save overheating them on the road however that then makes it a very difficult climb out of the track in the dry never mind the wet, traction control working overtime or just switched off and letting low range eat. Either way compared to having the tyres set just above the tpms warning where it just walks out no fuss at all wet, dry or something in between makes such a difference.

wrote:

Just out of interest what pressure do you have in the tyres? And more importantly have you checked it yourself rather than relying on what you asked the fitter set them to? 

I believe it's 26psi, whatever the placard says for the OE tire size, yes, I checked it myself. 
Just in case it matters to you, this Jimny does not have TPMS, it's just one of the features not offered in this market.

Tire differences - compared to the OEM tires (if I remember correctly Dunlop Grandtrek AT20, which is an all season highway tread pattern), the Grabbers are way more "sure footed" both in the wet & dry, there is a noticeable, but not significant loss of "zippiness", the car is noticeably more difficult to roll (as in you're outside of the car pushing it), but not enough to show up in the fuel consumption numbers, the wider tires and the all terrain tread pattern throw a heck of a lot more mud onto the sides of the vehicle, mud flaps are strongly recommended.

The 215/75R15 tyre size was selected to try to maintain a rolling diameter close to the OEM one, and also because Suzuki themselves have fitted this size to limited edition runs in some markets.