2nd gen legacy speed calibration

[awesomefacespacebear]

hey guys i want to move from 14 inch rims to 15 or 16 inch rims. my tire calculators all get sort of close when trying to calculate a close to stock combo replacement, but theyre still off and i wanted to know how you guys calibrate your speedo/odometers. The closest thing to my 185/70-14 was 305/30-17 and 225/35-18, next closest is 245/40-16.5 or 195/50-16.5. I want to get 15s or 16 and those are a lot less close in size. my only problem keeping me from the switch is the speedo/odo calibration. im not sure i understand what ive been reading but it seems like i need a gear in my cluster. Can someone whos had experience with changing wheel sizes walk me through the experience?

[awesomefacespacebear]

alternatively, whats a middle of the road 14inch rim? i want it to be a daily driver and/or light autocross rim? i dont want replicas and can shell out a bit more for quality. but want to keep it about 150 a wheel if possible.

[Go Mifune]

First, you might want to upgrade your brakes-most of us do- and then you'll need at least 16" wheels to clear the calipers.
Second, there's almost no autocross type of tire available in 14" or 15" for our cars.
If you go slightly too tall in a tire, the RPMs will drop on the highway which some like but acceleration will suffer a bit and your car will be taller.
Slightly too short gives you higher RPMs, a wee better acceleration and a shorter car.
Check out the Members Ride I section to see what others are running for tires.
Otherwise most people don't seem to care if the speedo is off by 2 to 4%.

I've run both shorter and taller tires without complaint. Too wide is more concerning and then you get into fender rolling and flares.

Here's a great post on tires-
https://sl-i.net/FORUM/showthread.php?10845-Widest-tires-you-can-run-without-rubbing

And lots of info here-
http://www.tirerack.com/content/tirerack/desktop/en/homepage.html

This might help-
http://www.willtheyfit.com/index.php?width=235&aspect=35&diameter=19&wheelwidth=8&offset=48&width2=225&aspect2=40&diameter2=18&wheelwidth2=8.75&offset2=35&Submit=Submit

And for reasonably priced but good wheels-
http://forums.nasioc.com/forums/showthread.php?t=2239019

For great aftermarket wheels, lots of cash seems to be important.

[awesomefacespacebear]

Thank you so much for the info!

[rkrenicki]

I would say, stick with stock legacy sizes. 205/50R16 (-0.5% error) or 215/45R17 (+1.7% error). They are both "close enough" that you dont have to worry about your speedometer, as the general margin for error in the speedo itself is larger than either. 16" and 17" wheels will be very easy to find with the correct specs as well.