Originally Posted by
Gowf
This maybe isnt the place to say this either, but you are talking in very generic and somewhat confusing terms when looking at cruise. A lambda value of 1, is used because of exhaust emission legislation. You DO get maximum economy (if we want to use this term) at a lambda of 1.1, however due to NOx issues this is not deemed acceptable (although there are ways of resolving this issue). Advancing the timing around the cruise areas may or may not improve your economy, leaner mixtures burn slower and so you find that you have to put more timing in for them, BUT.... you have to weigh in what the manufacturer has already put in place there (along with other factors such as speed, charge temp, etc). All in all, you have to remember that manufacturers have teams of people that spend months creating these maps, and do so for a reason, so changing these settings without true thought into why things do what they do can be quite detrimental.