235/50/19 tires on 19" rims??

[squiggyacfd]

When buying 19" wheels from tirerack.com as well as the tires that are already on the 19" G37 coupe, they suggest the size of 225/45/19 front and 235/40/19 rear. Why can't I use a 235/50/19 tires all around instead? These tires are literally under $200 for a H rating, all season tire compared to the other tires which are over $300. When comparing the two: 235/45/19 - Speed will be off (- .9 mph) from factory wheels/tires235/50/19 - Speed will be off ( + 1.1 mph) from factory wheels/tires

The only thing I can see that would be a problem is tire rub, however, I don't think even this would be an issue. If someone has any knowledge about this, please give me some feedback.Thanks everyone,Nic

Modified by squiggyacfd at 12:48 PM 4/25/2009
Modified by squiggyacfd at 12:51 PM 4/25/2009

[dividedhighw]

A taller tire will give better ride comfort, but lesser handling. Other than these two aspects, you've already hit on the 2 other main things to consider when using a different tire size, accuracy of electronically-imputed speed (e.g. speedometer, VDC, etc) and mechanical fitment (e.g. wheel rub if the tire/wheel combo is too high or too wide). If none of these is a practical issue for you, then go ahead and save some money.

As you correctly pointed out, with a higher profile tire speed will be off, in your example +1.1 mph, from factory wheels/tires, but be sure you understand that means the speedometer will read slower than your actual speed.

Although I've never bought anything from them, I've heard tirerack "knows their stuff", so you might want to pose that question directly to them.

Cheers,David

[jmess]

A wider and/or heavier tire will have some impact on fuel mileage and acceleration (added weight, increase rolling resistance, and some increase in frontal area (drag). Wider will provide less traction on slick surfaces due to creating less pressure per square inch on the slick surface. A wider tire will also tend to hydro plain when hitting standing water at a lower speed than a narrower tire.

[dividedhighw]

Thanks for the additions, jmess!

Congrats on hitting 100 posts!!

(BTW ... "hydroplane")

Cheers,David