The Basics: Air Fuel Ratios and Their It’s Importance Introduction: Here at Treadstone one of our main goals is to educate our customers to provide them with the knowledge to safely boost any vehicle they desire. This is why we have decided to introduce “the basics,” which will be a series of blogs that will present information in a simple to understand format with liberal use of lamens terms. Today we will cover the topic of Air Fuel Ratios (A/F) as always we will cover some definitions first. Air Fuel ratios are the amount of air entering the engine in respect to fuel in other words mass ratio of air to fuel present in an internal combustion engine. AFR is an important measure for anti-pollution and performance-tuning reasons. i.e. If your aftermarket A/F gauge reads 12.6, this means that for every 1 part fuel entering your internal combustion engine there are 12.6 parts of air also entering your engine. How They Work? The mechanism in most sensors involves a chemical reaction that generates a voltage. The engine's computer looks at the voltage to determine if the mixture is rich or lean, and adjusts the amount of fuel entering the engine accordingly. Their Importance! As illustrated below AFR play an important part in both economy and performance not only to the after market but to the OEM builders and engineers as well. If you note the picture above shows that maximum power is achieved with a AFR of 12.6:1, this AFR on a turbocharged engine this may lead to per-ignition (knocking/detonation) and server engine damage. Depending on your setup and tune a AFR of 11.5:1 to 12.0: 1 is the maximum recommended AFR a turbocharged engine should see, and should only be achieved with proper tuning methods. Conclusion Whether tuning for economy or for performance keeping a keen eye on AFRs should always be on the top of the priority list. To make sure there is a keen eye on AFRs Treadstone Performance Engineering recommends the use of an experienced and qualified tuner and the use of an after-market AFR gauge.