Speedometer off...

[galletaloco05]

hey all i have a 66 mustang. the speedometer is off by about 10mph (im goin 40 but it says 50) ive changed out the speedometer cable but it is still off. anybody have an idea on whats wrong or what i need to do to fix it?

[eggfarmer]

Check your tire and wheel size. You might need to change them out to avoid getting tickets or beaware of your speed and drive accordingly. I got a ticket once because the factory installed a drive shaft that was a little to long.

[scottngio]

Originally Posted by galletaloco05

hey all i have a 66 mustang. the speedometer is off by about 10mph (im goin 40 but it says 50) ive changed out the speedometer cable but it is still off. anybody have an idea on whats wrong or what i need to do to fix it?

I have a 66 too and was told yes your tire size makes adifference but if you like the aggressive look of your wheels then there are different plastic gears for about $15 dollars that change the speedometer ratio to fix this problem. i hope this helps