What the oil life percentage is actually telling you
Many newer vehicles no longer show a fixed mileage for the next oil change. Instead the dash shows a percentage, counting down from 100, and a message when it is time. Owners tend to treat the number in one of two ways: as a fuel gauge, or as something to ignore in favor of a sticker on the windshield.
Neither is quite right.
It is a calculation, not a sensor. On most vehicles the system does not measure the oil itself. It estimates how worn the oil is from how the engine has been used: engine revolutions, temperatures, number of cold starts, time spent idling and the like. A vehicle doing short trips and plenty of idling will count down faster than one doing steady highway miles, which is the point.
It needs resetting. The percentage only means something if it was reset at the last change. If an oil change was done and nobody reset it, the countdown is measuring the wrong oil.
It does not check the level. The monitor estimates condition, not quantity. An engine using oil between changes can run low while the percentage still looks healthy. Check the dipstick, or the level display if your vehicle has one, every few fill-ups.
Time still counts. Most manufacturers also set a maximum time between changes, whatever the percentage says. A vehicle that barely moves can need a change on the calendar rather than the counter.
When you bring it in
Mention the percentage it was showing and whether it was reset last time. The store can match the oil to what the manufacturer specifies and reset the monitor before it leaves.
While it is here
An oil change is a natural point for a look at the rest of the vehicle under scheduled maintenance, and the visit can be lined up with a state inspection if one is due. The national oil change page explains what is included.
Nearby stores
Fenton and Washington also change oil.
About this store
The De Soto store is open until 5:30 PM and is managed by Cathy Bequette.
See the national oil change page for all 33 locations.