|
S2 Elise Cd 0.407, A 1.6 m2, CdA 0.651 (figures from Lotus).
The first point is that while Cd is a good measure for effects of changes made to one vehicle, it is not that useful to compare Cd between vehicles because of the variance in cross sector. Thus now the trend is to use CdA (CD x Area).
The second, and most important point, is that the Cd figures quoted by manufacturers are claimed figures. There is no verification or independent test for them. Do not believe the figures that you see - the actual numbers can be much, much higher than what is quoted. Having said that, the Lotus numbers are probably accurate. Just don't use them in comparison with anything else.
|