Hi all,

Currently I have 225/55/16 tires on 16" Enkei alloys that came with the car when I got them. My max is a 99 GXE - I was wondering - what were the original wheels that came with this car (size wise)?

The reason why I am asking is because currently with the aftermarket wheels and tires, the car's speedometer is correct as per GPS calibration... this makes me wonder... if originally the car came with 15" steelies - how the hell is the speedometer still correct when increase the overall diameter by 1"?

 

How accurate is your GPS calibration or the nissan factory calibration?
1" increase in the diameter means 0.5" increase in the radius which means a 0.5/15 = 3.3% increase in the circumference. Is the speed calibration accurate up to 3%? For instance at 60 mph, 3.3% is ~ 2 mph.

 

im on 17in 2k2 rims and im off by almost 3 mph on the speedo. i have to go 42-44 to be going 40

 

When the needle shows 80 MPH, the GPS jumps between 79 and 80; so I guess about 79.5...

 

the GPS should be much more accurate than the speedo

 

hopefully someone will correct me if i'm wrong, but if you go up a size in the wheels you'll have to go with a tire that has a smaller sidewall to keep the same overall circumference of the tire/wheel combo.

you can use a calculator like this one to figure out what size tire you should go with in comparison to stockers to stay close to that circumference

i think thats what you were getting at....

stocks for your gxe were 15 inch wheel w/ 205/65R15 tires

 

All this means is that the stock speedo calibration is off with the 15" wheel package and it would be right on with the OEM 16" starfish which rock 215/55's.

 

you realize that the outer circumference has a lot to do with the tire and a little to do with the wheel diameter, right?