Tire pressure and diameter

[gone-ot]

..."TRIP" odometer should have one-decimal place accuracy, and thus will work fine.

...FWIW, most cars have wheel signals that provide 100X inputs per each 0.1 mile increment, although be aware that some (many?) engine computers "message" this information before it gets sent to the display and milage devices in the dash (GM seems to "add" 2 mph to actual velocity for some odd reason).