I know this topic has been touched numerous times. But I currently have a set of 2.0L Fuchs which I replaced my steelies with. I am running a 195/65r15 tire and my speedometer is 5mph off above 25mph. What tire size would you recommend to bring it closer to being accurate? Keep in mind I did have the speedometer repaired because my odometer/trip went out a few years ago. Your input would be much appreciated and thank you in advance.

I don't think your speedometer should be that far off at 25 mph. Are you certain the calibration is correct?

Check the diameter of your tire and see if it matches the one calculated below.

http://www.tacomaworld.com/forum/tirecalc....80r15-195-65r15

Click to view attachment

I know when I am doing 70 on the speedo my GPS says 65. 50 is 45 etc. Where would you recommend to go for a speedometer calibration? I currently have a set of Uniroyal Tiger Paw 195/65R15 on the 914. Though I will be replacing them soon as they have slight flat spots from sitting to long unfortunately.

Palo Alto Speedometer can do it:

http://www.paspeedo.com/ratio.htm

Speedo error due to tire/wheel size will be a certain percentage off, thus the error will increase with speed. Based on your numbers it sounds like you have a speedo problem.

Check on your speedometer case housing and see what weight size you have. I do not have one handy but I think it should read WT: .77. You might have a 911 speedometer and it will read WT: .80. This might be the case.