I just bought a 2004 Mazda 3s GT wagon and I need tires. It's got 205/50/17's on it. The look a little skinny and I'm thinking of going with 215/45/17's.
Will I have any clearance issues with this size? The sidewall will be lower and the tread wider than the 205/50's right?

Grant in Vancouver

 

215/45R17 will work just fine on the stock 6.5" wide wheels. You wouldn't want to go any wider than that as a 225/45 has a recommended rim width of 7". (That's the size I run 225/45 on 17x7 wheel)

 

Yep you shouldn't have any problems with the 215/45 thats what I run. (with a 7" wheel)

 

That's a good plus zero size, especially if performance is what your after. However, if everyday driving is more your thing, consider 215/50's instead. Here's why:
The overallcircumference of the 45 series tire is -1.42" from OEM. A good choice if a (very) little more acceleration is what you crave. But your speedo will read high and you'll be racking up more mileage on the od @ the same time. When your speedo read 65mph, your ground speed will be 63.83. @ 80, your actual speed will be 78.56, or 1.44mph slower than you think.
The overallcircumference of a 215/50 is +1.24" larger, or a 1.6% increase. @ 65mph the difference will only be 1.01mph, or 66.01mph actual speed. The difference is a little less from the OEM size. And, fewer rotationsfor a given speed should also give a slightly higher tire wear and better mileage, though a bit slower acceleration.
Thisis really splitting hairs, I know, but something to think about.