Hello...

noob so please forgive the stupid question.

I'm pondering geting some Rota SDRs for my wagon, but I fear it's going to affect the ride and suspension.

I shuttle my 83 year old gramps and various nursing home folk around often and the stock suspension is slightly on the rough side for them as is.

It's also too bumpy for my 2 and 3 year old nephews.

I love taking my family up to the snow and all of that and the wrx is the only one that can handle that...but if it gets any rougher, they won't want to go

Also would I have to recalibrate the speedometer to take into account the diameter difference?

thanks in advance

 

the ride comfort is mainly effected by the tires. having 17's shouldnt be too bad.

 

lighter wheels actually improve suspension performance. My friend went from heavy 15's to lightweight 17 and the car was more comfortable

 

IIRC, your spedometer reading will be off by like 3-5% depending on tire size. Playing with the tire pressure should help a little as far as being too bumpy.

 

I have 17'' Rota SDRs on my sedan and the ride is fine. I notice that the ride is SLIGHTLY more harsh than on stock wheels and tires but it is hardly noticable. The up side is WAAAAY better handling on the twisties.

Getting 17'' wheels and some good tires is some of the best money you could ever spend on your WRX.

 

I took the time to actually calculate the total diameter of different size tires.

Stock 205 55 R16's have a diameter of 24.88 inches

225 45 R17's have a diameter of 24.97 inches

it's about a 0.4% difference

That is the size most recommended and the closest to stock size which will give you the least error as far as speedometer and odometer readings.

 

It should not affect your speedometer too much, and here's why. If you buy the right size tire with 17's you'll have a lower aspect ratio of a tire than with your factory tires. However, your overall rolling circumfrence will be the same within 1-3%. This is an acceptable tolerance for your speedo anyway. You can see that much difference from a set of new tires to a set of worn out tires because of the loss of tread. I wouldn't worry too much. You may notice a small difference in ride quality. It depends on how stiff your sidewall is. Talk to Dexter at TireRack and see what tires he recommends.

 

Yeah - get the right sized tire and no problem with the speedo. Ride comfort can be improved (yes!) with the right tire. If you were to get a 17" wheel, you could use 225/45-17 in a touring tire. We tend to focus on performance tires in this forum, but there are many types to choose from.