Edge evolution
The air to fuel ratio that is consumed in the engine. "Lean" is a term that describes a scenario where your truck takes in more air than necessary which can be damaging to internal parts. The term "rich" is used to decribe when too much fuel is burned than required. This is harmful as well but very wasteful. The best example of that is with diesel trucks. They can purposely be programmed to run rich so they can produce a ton of black smoke out the exhaust.





