What does ODO mean on a speedometer? ODO vs TRIP explained

ODO is short for odometer. On the dashboard of a car, the instrument cluster of a motorcycle or a bike computer, the ODO figure is the total distance the vehicle has covered since it was built, in kilometers or miles.

ODO vs TRIP

ODO

Lifetime distance. It only goes up and can't be reset. Buyers, insurers and service schedules rely on it.

TRIP (TRIP A, TRIP B)

A counter you reset yourself. Common uses: reset at every fill-up to see the range of a tank, or at the start of a journey.

On many cars a button on the dash or the steering wheel cycles the display between ODO, TRIP A and TRIP B. Holding it while a trip counter is showing usually resets that counter. Check your owner's manual, as the button and the exact steps vary by make.

Why the ODO reading matters

• Servicing: oil changes, tires, brakes and timing belts are scheduled by distance as well as time.
• Resale: the odometer is one of the first things a buyer checks.
• Fuel economy: distance between two full tanks, divided by the fuel added, is your real consumption.
• Mileage logs: business mileage claims are based on the distance of each trip.

Why your odometer and GPS disagree

An odometer counts wheel turns, so tire size and wear change what it reads. Worn or smaller tires cover less ground per turn and make it read slightly high. GPS measures the distance you actually traveled, though it can lose a little in tunnels or dense cities. A difference of a few percent between the two is normal.

Keep an odometer on your iPhone

Odo, the app, is named after the odometer. It records the distance of every trip with your iPhone's GPS and keeps each vehicle's odometer current by adding your trips to the last reading you entered. With an OBD2 adapter, cars that report their odometer can update it directly. That keeps mileage-based service reminders on time and gives you a per-trip driving log you can export.