I need some Info? Hopefully someone on here will have some Insight On this? I may be picking up a set of G37 19's with tires. pretty much brand new with about 100mi on them. Now if i throw these rims on in place of my Sports 18's, will my speedo read Incorrectly? Or will it be Fine? Or will it read off like +or - 5 mph?? Just wanted to know how much or if any my Speedo will be off. Thanx MIKE

 

Depends soley on tire size. I believe 245/40 -19 is about perfect. Off by less than .2 of one mile per hour.

When speedometer reads 60mph (96.6km/h) actual speed will be 60.2mph (96.9km/h): 0.3% faster.

http://www.rims-n-tires.com/rt_specs.jsp

 

Look on Tirerack.com - they have all the tire specs/diameters etc, so you can compare the stock tire diameter to the new one.

 

Use this tool...it will tell you exactly where you are at on your speedo. Its a sticky in the tires section of this forum. Great tool in deciding what tires to put on.

As for your wheels...keep us posted. Your ride is sick anyways, and I love the look of the g37 wheels. Make sure to post pics...looking forward to it Mike...

 

Thank's for that Link Ivory! Appreciate it! That calculator tells me the new G37 rims and tires are about the same as my Sport 18's, and the Speedo will barely be off or anything at all, will be perfect! I'll definatley post Pics if I get them! Your G is not too shabby Either dude!

 

Finally dropping the $ on the 37 rims, eh Mike? Your car will look awesome with those on! Just in time for the next cruise bro!

As far as your question, most plus size wheels don't change the overall diameter of the wheel height. Its just that the ratio of rim to tire gets higher. More wheel/less rubber. If you line up a 20 inch wheel with 30/35 series tires next to a stock 18/19inch wheel with 40/45 series tires, the overall height is the same. They just look taller and bigger because there's more wheel.

Can't wait to see pics Mike! Post'em up ASAP!