FlexFuel Capability
The Vortec 4.8L, 5.3L and 6.2L V8 engines available on Silverado 1500 can operate on either regular unleaded gasoline, E85- a blend of 85% ethanol and 15% gasoline - or any combination of both. Because ethanol is made from primarily organic, domestic resources, E85 is a mostly renewable, cleaner-burning fuel that can help reduce our dependence on petroleum and reduce tailpipe emissions. Plus, E85 generally has a higher octane rating than regular unleaded gasoline, which can result in slightly higher horsepower and torque levels.
Power and efficiency are the trademarks of a Vortec engine.
The Vortec 5.3L V8 engine included on Silverado XFE offers an impressive combination of 315 horsepower and an EPA estimated 15 MPG city, 22 highway when running on gasoline - a fuel economy number that's better than Ford F-150, Dodge Ram and Toyota Tundra.

Engine: Vortec 4.3L V6 HP @ RPM: 195 @ 4600 Torque @ RPM: 260 @ 2800 Standard Transmission: Hydra-Matic 4-speed automatic overdrive Engine: Vortec 4.8L V8 HP @ RPM: 302 @ 5600 Torque @ RPM: 305 @ 4600 Standard Transmission: Hydra-Matic 4-speed automatic overdrive Engine: Vortec 5.3L V8 HP @ RPM: 315 @ 5200/326 @ 5300 Torque @ RPM: 335 @ 4400/348 @ 4400 Standard Transmission: Hydra-Matic 6-speed automatic overdrive Engine: Hybrid Vortec 6.0L V8 HP @ RPM: 332 @ 5100 Torque @ RPM: 367 @ 4100 Standard Transmission: Hybrid-specific Engine: Vortec 6.2L V8 HP @ RPM: 403 @ 5700 Torque @ RPM: 417 @ 4300 Standard Transmission: Hydra-Matic 6-speed automatic overdrive