GET THE FULL STORY ON DIESEL TUNING WITH FAST™ For years, the only device available for measuring the state of tune in a performance diesel engine was an exhaust gas temperature (EGT) gauge. While this is an important tool, it only delivers half the tuning equation. With the FAST™ Diesel Air/Fuel Meter, you can check engine efficiency at wide open throttle and make adjustments to your air/fuel ratio that will help draw the maximum horsepower from every drop of fuel that you burn. Compatible with diesel and B20 blend bio-diesel fuels, the FAST™ Diesel Air/Fuel Meter features a large, easy to read, backlit display screen that shows your A/F ratio in realtime. Touch of a button, and the unit’s built-in data logger records your A/F ratios for later review -with no need to download the information to an external computer. When connected to the optional FAST™ Air/Fuel Meter RPM module, you can view engine rpm as it corresponds to air/fuel meter readings, allowing you to focus in on the rpm range that requires additional tuning. The FAST™ Diesel AF Meter is available in both economical, scalable single sensor and flexible dual sensor versions. The 2-sensor version allows you to measure air/fuel ratios in two different locations at the same time for maximum sampling accuracy. Advanced features also include outputs for data logging software and external digital gauges. See the chart below for part numbers and accessories.