Speedometer Theory

[josh18_2k]

or maybe you're only locking one wheel when you pull the ebrake.
with an open diff, the speedo could stay the sameish speed while sliding around. one wheel slow + one wheel fast, speedo will see the average of the two.

[Pete_89T2]

Originally Posted by josh18_2k

or maybe you're only locking one wheel when you pull the ebrake.
with an open diff, the speedo could stay the sameish speed while sliding around. one wheel slow + one wheel fast, speedo will see the average of the two.

Why would it average wheel speeds? As Ted described, the speedo is driven by a by a cable, which directly connects to a plastic gear in the transmission - it's spinning in direct proportion (based on gear ratio) to RPMs the transmission output shaft/driveshaft is spinning.