question regarding switching from 205/55/16 to 215/45/16?

[stmike1]

Hi, I have a 2102 3 Skyactiv hatchback and am not a fan of the stock tires (is anyone?), but like the wheels and do not want to fiddle with new rims. I can get 215/45/16 Ecsta XS's, which are very sticky summer tires. Any drawbacks to look out for besides worse MPG and less tire life?? I think the increased width and square look of the tire will compensate for a little more fender gap. Thanks a lot for the feedback.

 

[leeharvey418]

215/45R16 is WAY too small. You should be looking at 225/50R16 to match your original tires' rolling diameter. There are a whole bunch of really good performance options available in that size, and they'll mount up just fine on your 6.5" wide wheels.

 

[stmike1]

I checked it out and there are a lot in the size you suggest.

I have decreased rolling diameter on cars in the past, and everything worked out okay. What is the worst case with 215/45/16?

Thanks for the help.

 

[leeharvey418]

The first problem is that your ride is going to suffer. And you could potentially be denied any warranty claims related to suspension or driveline components.

More wheel revs per mile traveled means:

Speedometer will be off (reading faster than what you're actually going - not necessarily a bad thing)
Engine and driveline components will wear faster
Fuel economy will take a hit

And since you asked about worst case - the load rating on a 215/45R16 is 86, while it's 88 on a 205/50R17 (and I didn't look up the load rating for a 205/55R16, but it's even higher than the 17" tire). Having a lower load rating than the lowest one for any available wheel and tire package for your car means that should anything ever happen and somebody wants to sue you, their lawyer will have ammunition to use against you. But like I said... that's hypothetical worst case.

 

[stmike1]

Thank you for the feedback.

Correct me if I'm wrong, but I assume that the engine and driveline components will wear faster simply due to running at a higher revolution on the motor, and not some bigger issue I'm missing.

Looks like the load rating is 91 for the stock tire.

 

[leeharvey418]

Right - everything from wheel bearings up through the transmission an all the way to pistons and valve train will wear faster owing to the fact that they're effectively moving farther to push the car the same distance.

A load rating of 91 sounds reasonable for a 205/55R16. Really, though, you only need to shoot for the lowest OE tire load rating that's offered on a comparable car, and that'll be the 88 of the 17" tire (and also the load rating of the 225/40R18 Mazdaspeed3 tires). It's not that your car will spontaneously explode from running a tire with a lower load rating, just that you're running the risk of some shyster convincing 12 idiots that the load rating of your tires is what caused their client to run into you.

 

[stmike1]

Okay, thanks.