I would like to discuss something that has been bothering me for a while. A-b-a testing is difficult under any conditions, but it would seem virtually impossible to get accurate testing on an Insight 1.
All of us who have tried a-b-a testing know the problems. There are numerous small pertubations which can lead to inconclusive or outright false results. These pertubations include, but are not limited to, changing weather, winds, inconsistent throttle, warming engines and tires, and changes in tire pressure. With experience, many test operators learn to control many if not all of these variable to acceptable degrees. These tight controls frequently reduce the opportunities to test, but delayed data is preferable to erroneous data.
I am particularly concerned with a-b-a testing on the Insight 1, including my own. In addition to the normal frustrations with stable baselining and testing, there are some extra variables which seem particularly difficult. The three big problems which come immediately to mind are: 1. The lack of cruise control dictates that the operator maintain an almost impossible level of manual throttle control. (As owners know, the car FCD is extremely sensitive to the throttle.) 2. The difficulty of controlling inefficient regeneration causes errors in the fuel consumption measurement. 3. Any deviations of SOC from full will cause background charging which will cause fuel consumption errors.
I personally would like to hear some ideas on controlling these problems. I live in Richmond, VA where we have hills north, south and west. I may be able to find a testable road section by traveling most of the way to Norfolk, but I'm not aware of any such road, and population densities off interstates would argue against any such road.
Perhaps the best testing of aero mods would be achieved by doing Cd measurements by coast down, rather than the traditional a-b-a testing. Any thoughts
