Glossary / General

fuel trims

8 Episode Mentions

Too Afraid to Ask

The car’s computer keeps a running tally of how much extra or less fuel it needs, and these numbers show that adjustment over time (long‑term) or in the moment (short‑term).

Technical Definition

Fuel trims are adjustments the ECU makes to the fuel injection map based on sensor feedback, with long‑term trims reflecting cumulative changes and short‑term trims reacting to immediate conditions.

Hear It Discussed

"checked the fuel trims. They're good, like around two or three percent."
Guys Giving Free Car Advice Over The Air You Can Call Too Under The Hood show 01:44

"[49.8s] You know, I want to go back and talk real quick before I go to George and Alabama about fuel trim's or fuel economy once again... [73.8s] We assume if there's no check engine light on the..."
Ron Ananian, The Car Doctor - May 9, 2026 - Hour 2 - The Problems Your Car Isn’t Warning You About Ron Ananian The Car Doctor 00:49

"The fuel trims, both short term and long term closed loop trims [3927.5s] varying quite significantly."
161: Standalone vs OEM ECU: Understanding Modern Engine Control Tuned In 05:22