Finally! - My Wider Wheels/Tires Project

Don · Aug 28, 2018

View attachment Don33[1].jpgI bought these wheels a couple years back and it's taken me that long to get them on the car

Rear Tires are Continental ProContact TX, 185/60R15 on 15 X 5.5" BMW Mini wheels. Fronts are Continental EcoContact 175/55R15 on 15 X 5" wheels. No issues with regen. Although I don't have many miles on them as yet, the tires are very quiet and the car drives much differently . . . . or so it seems to me

Don

jray3 · Aug 28, 2018

Congrats Don! No hope for using Miata wheels, IIRC? Now that I also have an electric NB (2nd generation) Miata, I'd love the ability to swap wheels.

Don · Aug 28, 2018

15" Miata wheels will work - The bolt pattern and centerbore is right. They're too wide for the front though, just as almost every wheel out there is. These Mini wheels I used are too wide for the front too, so I 'shrunk' the front pair from 5.5 inches down to 5, and they fit fine using the stock lugs and no spacers

Don

Don · Sep 11, 2018

For anyone wanting wider front tires, a simpler solution might be to find a pair of iMiEV rear wheels and mount a pair of 175/55R15's on them and try them on the front. I know that if you pull the steel collar out of the front hub, a rear wheel will bolt on the front - I tried that long ago. The centerbores are the same, it's just that steel collar Mitsu put on there to make sure a tire tech who wasn't paying attention couldn't inadvertently put a rear wheel on the front

When I put the Mini wheels on my car, I had a pair of them cut on a lathe and then welded back together to make me a 5" wheel from a 5 1/2" wheel - That's lots of work and probably quite a bit of expense, if you don't have helpful friends with the appropriate tools. In my case, it didn't cost me anything

Anyway, I tried my wider front pair with my stock 175/60R15's on the back just to see if it disabled regen or not - It didn't. The 175/55R15's are only 0.6% larger in circumference than the stock 145/65R15's. You could run 175 tires all around if you wanted - 175/55's on the front and 175/60's on the rear. Since I was buying new tires for my new wheels and wanted the rears a bit larger too, I used 185/60R15's on the rear. Those work with no regen problems too

Since I now have an extra set of wheels, when Carolyn's car needs new tires, I think I'll try the 175/55's on the front using a pair of rear wheels

Why Mitsu went with the 145's on the front, I have no idea. Maybe it made some sense with the original kei car which was so tail heavy, but the EV version has nearly 50/50 weight distribution because of the added weight of the battery in the middle. The car sure drives different with larger tires on the front

Don

wmcbrine · Sep 13, 2018

Don said:
The car sure drives different with larger tires on the front

Could you please elaborate on this?

Don · Sep 15, 2018

Well, it might be just my imagination, but with 40 psi in the 175's (same pressure I always ran in the 145's) the tires seem much 'cushier' when you hit a bump, like the tire is absorbing more of the shock. I'm sure there *is* more cubic inches of air in the tire, but the sidewall is the same height. I wasn't expecting this at all, so it's probably not my imagination

The pronounced understeer is all but gone now - Before, if you pressed the car at all in the curves, the front tires wore much faster than the rears - We'll see if that's still the case, because I feel much better about maintaining speed around corners than before, so I'm doing that lots more

Don