Air Fuel Ratio

Hi, so if tuning with lambda is easier why not many tuners do this? Because sometimes there´s no need of using e85 or other fuels? And is lambda the same as using an A.F.R gauge?

There may be two main reasons - it's what many 'tuners' will be familiar with, having been brought up on petrol/gasoline, and many gauges being calibrated for petrol/gasoline.

Getting used to lambda is a good idea, IMO, as it's consistent regardless of the fuel used - 1.0 is stoichometric, chemically balanced, 1.0 is leaner.

Sort of, the actual value is in lambda, converted to AFR - FOR THE SPECIFIC FUEL IT'S CALIBRATED FOR!