GM's 2027 Truck Launch: New V8s, 555-HP Diesel, and the End of the Oil Dipstick
General Motors has unveiled the powertrain lineup for the 2027 Chevrolet Silverado and GMC Sierra, featuring new sixth-generation small-block V8s and a record-setting heavy-duty diesel. The new 5.7-liter L76 and 6.6-liter L78 engines replace older units with increased power but remove traditional oil dipsticks in favor of digital monitoring. The heavy-duty segment gains the 8.3-liter 'Mongoose' Duramax turbodiesel, which produces 555 horsepower and 1,230 pound-feet of torque, surpassing Ford's Power Stroke. GM emphasizes that these engines were designed for real-world truck usage, including towing and off-road capability, while maintaining a strategy that balances internal combustion with future electric vehicle development.
