15" versus 17" wheels & mpg/gauges

You are correct, as long as the 15 inch wheels have appropriate tires on them they won't mess anything up.

If you don't have TPMS tire pressure sensors on your winter set up, you'll just have to ignore the warning light on your dashboard.

 

I would say, it takes more energy to rotate a 17" metal rim vs less energy to rotate a 15" metal rim.

Also, depending on the size of tires, they may be different diameters and may take more of a rotation to complete on the larger diameter rim/tire combo which will throw off the on board computer of the prius since it was originally spec'ed or calibrated to whatever originally sized tire/rim that came on the vehicle.


iPhone ?

 

Our stock tires are 215/45R17, and every winter I switch over to 195/65R15 snow tires, mounted on Corolla rims, sans tpms sensors. No problems. The diameters are very close, on purpose: they are interchangeable. The 17" has very slightly smaller OD, but affects nothing.

When I was shopping snow tires I contacted our local dealership, the one we bought from, and got an earful about the Prius being a "flagship" vehicle, not steel rim available. In exasperation I emailed all the dealerships in the area, and one came back right away, with a quote, saying they thought Corolla 15" steel rims would work. And they did, lol.

Here's a little info on our setup:

Corolla steel rim, part no: 42611-02471 (2003-2008 corolla or matrix, CE, LS, S)
steel rim lug nuts: 90942-01007 (plain, open-ended, galvanized)

The rims were $70 apiece, and the lug nuts somewhere around $30 for the lot. I could have just bot the parts and headed for Costco, but elected to let them do the full deal, just in case there was a clearance or fit problem. Worked out fine.

 

OP, the Prius 17" alloy wheels and 15" steel wheels use different style lugnuts. That's why Mendel mentioned getting a set of lugnuts along with his winter set.

 

Yeah, the lug nuts used with the alloys will actually work, but they look odd, stick out and have loose washers. They will work with the (steel) temp spare, for example. But it's nice to get some regular lug nuts. The dealerships will know what's compatible.

I also put a 2" ABS pipe cap over the center hub opening, with a rubber band section cut from an bicycle inner tube to act as an O-ring. Just started doing that this year, and it's a good fit, and shows no signs of coming off. Almost presentable, lol:

 

Turns out the rims were fine, but the dealership wasn't sure, I was the guinea pig. These are all Toyota parts, and I let them do the whole thing. But yeah, you could just get the rims and go to Costco. Their prices tend to be lower, and if there's rebates they take them off at time of sale, saving you mail-in hassle AND some sales tax.

One caution: those are Corolla rims, fit the centre hub precisely. Any aftermarket rims will have oversized centre hole and you should use an adapter ring. Other wise the load is being taken by the lug nuts and studs.

We went 4 winters with those before I experiment with the centre caps. The hubs get really groady/rusty, to the point it might be hard to remove the nut, if needed, especially on the fronts. I just picked those up at Home Depot, they're an end cap for 2" abs pipe, about $3~4 apiece. They won't stay on (on Corolla rims) all by themselves, but when I slipped an innertube rubber band over the the hub opening first, they're secure. The front case it won't quite push all the way down, but it's ok, very close.

You could dress it up more with some closed acorn-style nuts. I was stuck with those open ended ones, so I treat them with a little wax/oil rust preventative, just very sparingly. They're galvanized, but still it helps.

 

You shouldn't have too much trouble finding Prius OEM 15" rims for a good price. I regularly see it here in CA for about $200 a set.

 

FYI, the Costco tire centers where I live will not work on nor install any tire size or rim that is not original equipment size for your vehicle. Even if it comes standard on another trim level on the same type vehicle.

Talk about a CYA corporate policy.

However, I would think they wouldn't be as strict when it comes to a second set for winter use.

 

Well the Prius has 2 standard sizes, both 17" and15". Maybe ok?

 

I bought my snows from Tire Rack and got a package deal that amounted to 4 15" aluminum rimes for about $50.00 each.

Already mounted, delivered to my door.

Unfortunately the package is a little more expensive this year.

 

Cap secured with no slip stair tape.

 

We've actually got some snow today, eh?

 

We have had a 67 degree swing in temperatures from -20 F to 47 F today in two days but no sunshine.

 

Slight hit in MPG from going from 15 to 17 inch wheels. I have seen about a 3 MPG decrease.

 

If you go a forged 17 the mpg loss would be even less or almost maybe none

stock 15 inch 14.3 lbs

aftermarket 17inch te37 15.7 lbs

 

The biggest reason I could think of going from 15 inch to 17 inch wheels would hurt gas mileage would be the type of tire assuming the diameters are the same. A pond difference in weight would not cost 3 mpg.