I know that adding a larger wheel/tire combo can effect the accuracy of a speedometer. How does this work for our cars given that there are 2 or three different wheel sizes depending on the package/year? If you opted for the larger wheel package did this include a different speedometer calibration?

Also considering swapping to G35/G37 wheels and was wondering people's experience was that have done this swap?

The smallest OEM wheels/tires for the EX35 were 225/60R17, and 225/55R18 were optional. I don't believe that there were any tweaks to the speedometer, as the difference in circumference between the two sizes was only 0.4%. Later models had the option of going with 245/45R19, yet the overall difference in circumference is again 0.4%.

I don't think you really have to worry about the calibration of the speedometer as long as you pick one of the OEM tire sizes. The one thing you might want to look into is the wheel offset. I don't recall exactly what they are for the OEM wheels, but it's usually not a problem as long as you're not too far from the original offset or aren't going with a really wide wheel.

I personally have no experience with other wheels, but I am running a slightly smaller tire at 235/55R17. My speedometer does read a bit high when checked against those radar measured speed displays on the side of the road, but I don't remember how accurate my speedometer was to begin with prior to the tire change.

Thanks for the reply!

Site to compare various tire sizes..

http://tiresize.com/comparison/