New world's best Cd for a current production car: 0.24, Mercedes 2009 E-Class coupe

[lunarhighway]

sorry if i was unclear in my prev post. i didn't mean these where saloons with a wiper, but at least on the belgian opel site the rear wiper on the hatch is listed in the car configurator as a 75€ option. i suppose certain trim's have it as standard, but i guess it means if you really want you could have a standard hatch with or without the wiper. the 3d presentation on the site also whows the hatch without the wiper.

what i meant was because the cars where so similar if the saloon doesn't need a wiper the hatch shouldn't really need one either, wich could explain why it's optional rather than standard, also the car does look better without it.

i have a vectra A (cavalier mk3) hatch, wich is roughly similar in layout to the insignia hatch, and i notice that at speed ,even in heavy rain, no drops fall on the rear window , but at speeds lower than 50km/h they start to settle and the wiper sometimes comes in handy, especially while parking.

last summer i took the wiper off for aero reasons, but in winter i put it back on, the effect on FE is likely small although i do suspect because of it's position to the side it will interfere with the flow comming off the C pillar

[Otto]

Originally Posted by MetroMPG

You should splurge for the book. You'll get more quality time out of it than you will spending an equivalent amount of $ on movies! Every once in a while one comes up used on eBay for a bit less.

Yes, detail optimization is basically "tweaking", as you said. Optimizing cooling, wheels, mirrors, glass & window/door seals, leading & trailing edges, slight taper, etc.

The shape alone doesn't mean much if the details are all wrong. You could easily take a 1st gen Insight and put its .25 Cd past .30 with wider wheels, blender rims, a badly designed front fascia, no rear skirts, unoptimized underbody, too much grille, etc.

No, don't splurge. Instead, do inter-library loan for free. Use the book for a month, photocopy or scan relevant pages for future reference, and use the money saved for Coroplast or whatever. Mo better.