General Motors has decided to make some 2021 full-size pickups without a certain fuel management module because of the ongoing microchip shortage. As a result, those trucks will get around one fewer mile per gallon of gas, meaning they’ll burn more fuel to go the same distance, releasing more carbon emissions into the atmosphere.

The trucks affected are models that use GM’s 5.3-liter EcoTec3 V8 engine (including versions with six-speed or eight-speed automatic transmissions), according to Reuters, which first reported the decision. That includes the popular Chevy Silverado and GMC’s Sierra.

The module is what powers the trademarked “Active Fuel Management” or “Dynamic Fuel Management” systems GM promotes on these trucks, which deactivates some of the engine’s cylinders to boost fuel economy. A company spokesperson told Reuters that the decision would affect GM’s fleet-wide average fuel economy, but that it wouldn’t be a “major impact.”

GM decided to make the trucks without the fuel module so as not to affect production. Ford previously announced it was briefly reducing output of its ultra-popular F-150 pickup as a result of the chip shortage. Automakers are dealing with a dearth of semiconductors in part because they originally lowered their forecasts of how many they’d need when sales first took a hit last year during the early stages of the pandemic. A spike in demand for consumer electronics only upped the scarcity.