I do that test for boats and street cars to determine cruise AFR. We ask the customer rear gear, tire size, transmission type, what speed/rpm they cruise at.... Then my carb guy literally re-calibrates a bunch of the carb circuitry to get us a nice lean cruise--then we go back and do some WOT testing to make sure its 12.6-12.9 (on this dyno). We usually do this near the end of the session as WOT testing is basically jetting related. My carb guru now has so much data that he refers to it and can correlate between the PVCR/emulsion package/jets/PV rating/and sometimes the IFR size and location. This is why its critical to have the right size carb to begin with. We've even had to change the main body (which my carb guy has everything onhand/onsite in order to do) because sometimes there's too much signal . This is time consuming but so worth it. I record this static cruise test usually for 10-15 secs and provide the printout at the end of the session. J.Rob