235/75R15 on JB74....

That's why I asked the question, is ground clearance important?

From my own experience, 20mm extra clearance under the diffs is not a major issue, especially when compared to the possibility of a roll over.

If you ground out, you can back out and try another line - no problem, but if your extra clearance leads to instability, then your chance of recovery are very slim.

Trust me, been there and done it.

Roger

Thank you all for the input. In the meantime - committed. The 235's are on the vehicle. The main prompt was a perceived lack of quality in the alternative sizes (they all seemed to be trying to look tougher than each other) and, ultimately, an indication that in the "outback," if there is tyre trouble, the 235 size much more available - because much more common. May be an expensive mistake. Will report after a couple of major on/off-road journeys, and also plenty of urban zipping about. Am hopeful the relatively conventional tread will reduce the inevitable impact on fuel consumption and drive train etc.

Very early days (1000 clicks) but vehicle delivering, almost precisely, the claimed fuel consumption figures of 8.2 litres per 100 kilometres for urban driving and 6.1 on the highway - at 100Km/h and 3000 revs - despite the increased tyre size/circumference/weight over OEM. The greater circumference (5.8% greater than OEM's) is also delivering, serendipitously, a speedo reading that is virtually spot on. (Assume the UK is the same as here in that manufacturers have built in an overestimate of speed.) As some reviewers have suggested, the feel on the open road is pretty "agricultural", and suspect I will settle for a pretty modest 90Km/h on long trips, which will need to be undertaken with good rest breaks: 100% concentration, while always at play in any vehicle, takes on a new meaning in the Jimny. You are "driving" it every inch of the way.

I went from stock to 235/75/15 A/T a week after getting mine. While I love the look I have a slight sense of buyers remorse. Although I wonder if any size up from stock would have had the exact same effect? It feels great on the road, but I don't know if I'm over thinking of the drastic reduced power and economy, or if it was simply always bad.

Consider that the tyres are 6% bigger than standard and the ways that this will affect the car.
In a given gear the car will move 6% further for every rotation of the engine. This means that the engine has 6% less mechanical advantage (torque) at the wheel. At the same time it will be travelling 6% faster. which means it will be fighting much more drag and resistance (drag increases exponentially with speed).
Now also consider that your speedometer and odometer are reading 6% slower than before, so from the drivers perspective you are subconciously drivng 6% faster than you did before, and basing your fuel economy calculations on 6% fewer miles... and the engine is having to work more than 10% harder.
All of these things combine to make the impact of a small change in tyre size seem massive. However if you re-callibrate your driving speeds and adjust your fuel economy calculations accordingly and the impact will be much less. Re-gear the transmission and the only difference becomes the increase in tyre weight.

As a side note, wide tyres aren't advantageous in any situation other than those requiring flotation (e.g. driving on top of snow or on sensitive ground such as peat bogs). For road/track/recreational use 235 is wider than necessary on a Jimny, and results in unnecessary weight and drag. 205/80r16 tyres would achieve the same increase in ground clearance and will give much better performance in all situations. The weight may be similar, but they will generate considerably less drag, especially noticeable when driving in mud and sand.

8.2 liters per 100 km = 34.4 mpg. The lowest I get is 42mpg.

6.1 " " " " = 46.3. " I have reached 49.5 mpg

As Busta said, the only benefits, that we can see are the aesthetics.

Roger