So does this just make the diesel more efficient? Sorta like a Prius for trucks?
Train engines have worked that way for years, so I'm not sure why trucks don't unless it was a battery or motor tech issue. trains are more weight agnostic than a truck.
Right from their website
A Worthy Electric Semi
Diesel locomotive style hybrid - electric drive powertrain build for the logging/vocational industry
A diesel generator and batteries working together to power electric drives
Better fuel mileage, lower maintenance costs, more power.
