Why is my fuel economy so low on a stop-and-go commute?

[George.R]

I’m trying to figure out if my car’s fuel economy is normal for my commute, which is almost all stop-and-go suburban traffic. My trip computer says I’m averaging 18 MPG, but that seems really low for a modern compact sedan, even with the constant braking and accelerating.

[Joshua66]

18 mpg in that kind of traffic would bug me. In my compact I usually see roughly 18–22 in similar stop and go, depending on how warm the engine is and how much the A/C is running.

[Paisley_W]

I keep reminding myself that the average on the trip computer can be user dependent; if you reset it, you might see a different number as it settles.

[Ella.H]

I once found the numbers were off until I checked tire pressure and brought the tires to the recommended 34/32; helped a bit.

[Paisley.J]

Have you checked if the display is showing average since last reset or a lifetime figure?

[Justin.T]

I tried turning down the fan and coasting more in gaps, the change was tiny.

[Noah41]

My car with a light roof rack loses more mileage in city than you might think; after removing it I dropped a notch.

[StellaEJ]

Honestly, maybe it's just a slow warm up or the city cycling, hard to tell without a real test.