Electronic Fuel Injection (EFI) is a technology that replaces the carburetor on the engine with a small digitally controlled fuel system that more accurately delivers fuel to the engine based on air temperature, pressure altitude, throttle position, engine temperature, and throttle position. This system can help save up to 20-30% on fuel consumption while also actively managing engine temperature and eliminating the choke control. Some systems are closed loop, meaning there is an oxygen sensor in the muffler continuously feeding back exhaust information to the EFI processor. Closed loop increases the accuracy of the system however under high load conditions the sensor is sometimes not used because the engine may need to run at a higher fuel ratio to meet emissions standards to cool down the engine. Also, some EFI systems also offer an electronic engine speed governor providing a faster response to sudden loads.