Ideally, it's best to keep the overall circumference of a new tire the same as the circumference of the stock tire you're replacing and there are tire size calculators which will help you to do that. The rear tires are larger in circumference than the front tires and at a minimum, that exact ratio of F/R difference needs to be maintained pretty closely or regen and ASC will be disabled - The car's computer is
very picky
I replaced the stock front 145/65R15's with 175/55R15's (on wider wheels) and the rear 175/60R15 with 185/60R15's on one of my cars and that combination works because the difference in F/R circumference is maintained within 1% or so of the stock ratio, but others here have tried different sizes and had problems, so . . . . proceed with caution and post your results here so we all can learn from your success . . . . or failure
Doing as little as installing European 175/55R15's on the rear of a North American iMiEV
will disable regen and other things as we have discovered the hard way . . . . and that's a pretty small change in size from our 175/60R15's. Finding 16 inch tire sizes for the front & rear (you can't use the same size front and rear) will not be easy . . . . but I know it has been done, at least in Europe - I've seen pictures of Euro models with 16 inch wheels, but I have no idea if regen was still working or not
Also - Beware that anything other than true LRR tires designed for EV's most certainly
will result in some range loss, which could be as much as 10% or so, depending on the tires you use - Over inflating an ordinary tire does little to make it behave like a true LRR tire so far as range is concerned, as many of us have also found out the hard way :shock:
Don