The RCCI engine uses both gasoline and diesel fuel

When most of us pull up to the pump, we are in vehicles that require gasoline. A portion of us sidle up to diesel pumps. In the future, maybe we'll we'll drive vehicles with RCCI engines and we'll need to hit both pumps. The Reactivity Controlled Compression Ignition (RCCI) engine is a concept engine being developed by the University of Wisconsin-Madison, and it only exists in the lab. What it's capable of, however, could be revolutionary. The RCCI engine can deliver up to 60 percent thermal efficiency. As for gasoline engines, the Toyota Prius's engine will hit a remarkably high 42-percent thermal efficiency, while the Mercedes-AMG F1 engine reaches to 50 percent. Most other gasoline engines have thermal efficiencies in the 30-40-percent range.