Odometer not working properly

PETERAC

MEMBER
2015 TOYOTA AVALON
3.0L
6 CYL
2WD
AUTOMATIC
20,500 MILES

The car listed above is not a hybrid. Mileage shown on computer display dropped from 18.6 to about 15 recently.

When purchased new in 2015 city, highway mileage was always about the same via the computer, 30 MPG on highway trips of decent length and 18.6 (give or take decimal point) city stop and go short runs.

Tire pressure always correct. Air filter changed yearly hardly dirty. Oil changed 3 times since purchase, which means it had new oil when purchased and then 3 changes since.

Tires new on front as of 2 year ago. Battery less than 1 year old. Air filter 60 days old.

So took a 14 hour trip one way and MPG per display was about 30 MPG as expected. Same on way back.

With last fill up since trip the MPG in city / running errands drop from my expected 18.X to 15. I reset the computer and then changed to Sport and Eco mode and back to normal, which I read online to do. I always run in normal mode. Only had 1 fill up since trip and put on about 120 miles.

Perhaps bad gas? A fluke?

Do not want to throw money in fuel injection or something else if it is an anomaly.

Any thoughts?

Thank you very much.

Peter

3 Replies

SQM

MECHANIC
6,383 POSTS

Hello,

You might not have enough data to determine if it is a trend. As you mentioned bad gas can lower mileage by couple of MPGs.
If there was an issue with lets say injectors, you probably will have drivability issue, it could have rough idle etc.

It could have triggered the check engine light as well.

See if you can smell fuel from the exhaust while running. It will suggest it is running rich.

From what you are describing you have been keeping everything up to date with the maintenance which is surely the right thing to do.

It is unlikely the injectors are an issue as you do have just over 20,000 miles.

Unless you are experiencing any issues, just keep an eye on it and maybe get fuel from a different station than last and observe the mileage.

https://www.youtube.com/c/2carpros/featured

Let me know what you find.
Thank you.