12.5-12.6 is the theoretical maximum power for petrol, but some N/A honda engines seem to make peak power when a little leaner than this, so potentially if you spoke to someone who tunes those then 13.1 might be a genuine figure he has worked to.

For a cossie, high 11s or VERY low 12s is where its at in order to control temperature, but again there are many reasons for it to vary.


What engine are you talking about?