The Mystery of Air/Fuel Mixture Revealed

An engine running too rich or too lean, and OBD codes related to air/fuel mixture control – it all may sound very mysterious, especially if you’re driving a car, but you’re not a car freak.

It’s actually simpler than it sounds – air/fuel mixture is all about how much fuel there is in an air/fuel mixture that enters the engine when it runs. Too rich means that there’s too much fuel, and too lean – the opposite. Both are incorrect and can be harmful.

There’s also something called mysteriously Lambda 1, or a stoichiometric mixture. It means that the mixture ratio is perfect for a gasoline engine and there’s no risk that the engine will get hurt. This perfect ratio should be 14.7:1 (it means that there are 14.7 parts of air to one part of fuel). It’s the most efficient ratio when it comes to fuel economy and emissions, but if you want your car to generate more power, you will have to achieve the ratio of around 12:1.

The air/fuel mixture should be correct at all times if you care about the state of your engine – and you should. Keeping it at the optimal level will enable your car to serve you for longer. When an engine runs rich, the fuel emissions are too high and the fuel economy gets significantly worse, but when it’s too lean, it will burn much hotter and can actually hurt the engine.

If you want to discover something more about car troubles, emergencies, and car care, check out this infographic:


The Mystery of Air/Fuel Mixture Revealed