To expand a bit on that.

The gauge in lambda is .5 to 1.5

So, depending on what scale you have it on (gasoline in this case)

.5 to 1.5 lambda would be- 7.35 to 22.4 on a gasoline scale

4.5 to 13.5 on alcohol scale

4.9 to 14.7 on E85 scale


The gauge is just taking lambda and converting it to an AFR number based on what scale. So, he's running on gasoline scale and sees 10 to 1 air fuel that is .68 lambda. That's all you need to see to figure it out, scale (gasoline) and observed air fuel ratio on that scale.

In his case running C14, stoich is 15.07 so at .68 lambda it wa 10.24-1.

When he observed as lean as 13.1, that was .89 lambda so 13.41-1