As title, can a rich tune for wot (10's a/f) cause the piston rings to prematurely go bad? What are the target wot a/f for most of the common gas used today (91, e85, c16, methonal, ECT...) most people say 11.8 a/f. Is this target a/f okay for all the gas type.

 

The problem with 10's is that 10:1 is the lower limit on a few widebands. Meaning 9:1 or lower won't show as "too rich", it will just stay at 10:1. Alcohol fuels can run very rich because they don't wash away oil easily. Gasoline does, so running very rich can ruin your rings.

Different fuels will want different AFR's. C16 and E85 can be run leaner than pump gas, while meth is usually run rich. This takes into account lamda, or "perfect combustion" for each fuel.

 

What is consider leaner than pump?? With
e85 andc16.. 12's a/f? Can pump gas with full meth injection and pump gas91 with fullmeth injection have the same target a/f? What wot target a/f will be good for each??