AEM's new Flex Fuel Wideband FAILSAFE Gauge monitors ethanol content, air/fuel ratios, and manifold pressure, and has been touted as being able to prevent catastrophic engine damage. The new 52mm (2 1/16 ) FAILSAFE gauge can actively protect an engine if it senses the system is running lean or excessively rich. An internal data logger is included to capture up to 2.5 hours of data on a loop, and two analog outputs are available. After the engine is tuned and a safe operating window of AFR is determined, the Flex Fuel Wideband FAILSAFE unit continuously monitors AFR/lambda and boost/vacuum to ensure AFRs do not fall outside of the user-defined boundaries. If an out-of-range reading is detected, the gauge triggers a low-side output that can avert major engine damage.