putting smaller rear wheels on a gen2 Volt

[DannyEcoEV]

So I love the volts (and my egolf)

Anyway the TPMS sensor went out on a back wheel..
I found a deal online used, for 3 chevy sonic wheels 15" for $75 total.
( also had 4 spare wheels from converting my other volt from volt wheels to cruze wheels) I was able to sell one volt wheel on ebay for $400.

So anyway seeing that i needed a sensor.. I swapped the 2 rear wheels for
sonic wheels.. (so Now I have 5 spare volt wheels and 1 spare sonic wheel that i carry around for a spare. If i was only local i'd leave it at home, but i drive 2 hours away often enough, so it's in the rear). If i get a flat on the front, i'll swap the other front to a rear so the front 2 wheels have the same size to get home, since it's more important for them to have the same size up front in the drive train.

in theory since the sonic wheels are slightly smaller, they should turn more when slowing down and generate more regen power right?

Also the smaller size should be more aerodynamic and a smaller footprint on the ground to have less surface area available to pick up nails. Sure in theory there would be less contact for braking but I'm not speeding along.. i'm tryig to get teh best range. Also the 15" tires should be cheaper than the 17" if needing to be replaced later. (at that point i'd probably be switching to all cruze or sonice wheels, since the volt wheels are more valuable to sell)


Eventually I want to put on taller narrower tires but why waste the ones with teh stock size for right now and why spend money for something i dont' need right now. I think they are lighter too?

Right now i'm ahead of the game $325 and have the benefits listed above.

It doesn't seem to cause any problems..

Thoughts?

[freebeard]

I take it that you're taling about a -2 fitment, 17->15. Rim diameter and width is just the ball park. The tire width and aspect ratio are still TBD.

For instance the front of the Superbeetle runs 165/50-15, when historically I've run 145-15s. Rolling diameter is the same, but the contact patch is wider.

A narrow tire on a wide rim has better aerodynamics. Steers like a tractor across ruts, but won't carry the weight. The brakes can overpower the tires, downhill in the mountains.

[DannyEcoEV]

i think stock is like 215/50/17 on the volt

and on the sonic its like 195/65/15..

So it's smaller in height and width..

[Ecky]

Correct me if I'm wrong, but you only get regen from the front wheels. The rears are only along for the ride.

Generally speaking, a taller wheel (all else equal) has lower rolling resistance and weighs more. A wider wheel is going to have marginally more aerodynamic drag.

[Phase]

Originally Posted by Ecky

Correct me if I'm wrong, but you only get regen from the front wheels. The rears are only along for the ride.

Generally speaking, a taller wheel (all else equal) has lower rolling resistance and weighs more. A wider wheel is going to have marginally more aerodynamic drag.

Isn’t more weight bad?

[Ecky]

Originally Posted by Phase

Isn’t more weight bad?

Usually. You win some and lose some from upsizing a wheel/tire.

[freebeard]

Rubber weighs less than steel and about the same as aluminum (IIRC) so aspect ratio comes into play.

[Phase]

Originally Posted by Ecky

Usually. You win some and lose some from upsizing a wheel/tire.

when i get a 2023/2024 prius, i wa thinking of down sizing the stock 17 inch wheels to 15 inch wheels like last gen prius. was wondering how that would affect things

[Ecky]

Originally Posted by Phase

when i get a 2023/2024 prius, i wa thinking of down sizing the stock 17 inch wheels to 15 inch wheels like last gen prius. was wondering how that would affect things

I'd guess you would get 2-5mpg from it. Just make sure it fits over the brakes.

[CapriRacer]

Originally Posted by Phase

when i get a 2023/2024 prius, i wa thinking of down sizing the stock 17 inch wheels to 15 inch wheels like last gen prius. was wondering how that would affect things

Too many variables. The RR varies wildly within a given tire size, but the difference between the same tire in different sizes is fairly small.