The 2018 GMC Sierra 1500 could be equipped with four engines: a 4.3-liter EcoTec3 V6, a 5.3-liter EcoTec3 V8, a 6.2-liter EcoTec3 V8, or a 3.0-liter Duramax turbo-diesel inline-6. Each option offers a different balance of power, towing capability, and fuel efficiency.
Engine options and specifications
The following engines were available for the 2018 Sierra 1500 and represent the range of performance and efficiency GM offered that year.
- 4.3L EcoTec3 V6 — 285 horsepower and 305 lb-ft of torque; typically paired with a six-speed automatic transmission.
- 5.3L EcoTec3 V8 — 355 horsepower and 383 lb-ft of torque; commonly paired with an eight-speed automatic transmission.
- 6.2L EcoTec3 V8 — 420 horsepower and 460 lb-ft of torque; paired with an eight-speed automatic transmission.
- 3.0L Duramax turbo diesel inline-6 — 277 horsepower and 460 lb-ft of torque; paired with a 10-speed automatic transmission.
These powertrains gave Sierra buyers choices for everyday driving, heavy hauling, or highway cruising, with the diesel option emphasizing towing torque and fuel efficiency on longer trips.
Summary
In 2018, the GMC Sierra 1500 offered four engines: 4.3L V6 (285 hp, 305 lb-ft), 5.3L V8 (355 hp, 383 lb-ft), 6.2L V8 (420 hp, 460 lb-ft), and 3.0L Duramax diesel I6 (277 hp, 460 lb-ft). Transmission pairings included six-, eight-, and a 10-speed automatic depending on engine choice, delivering a versatile lineup for work, recreation, and efficiency.


