Club 80-90 Forums

so... is there anything that can be done to help a T25 slip through the air a bit better - any sort of body kit, a certain shape of roof, etc...? If so are there any hard facts about how much MPG is improved.

I would guess that adding any sort of spoilers or panels to the outside would surely only increase the drag - even if made the shape more aerodynamic, the size of the actual cross-sectional area presented to the wind would be bigger and the van would also be heavier... And if it was all sleek and teardrop shaped it just wouldn't look like a proper brick anymore either, eh? And that would be a bad thing, right?

Regarding the roof I find that driving with the poptop down really helps...

Hi top is best. Try a search. Kev the rev posted a good thing about it with cd factors.

Why bother just reaise that these vans are bricks and should be driven so!

i found that if i removed the windscreen and left the rear tailgate open it helped

trikepete wrote:i found that if i removed the windscreen and left the rear tailgate open it helped

While in france in a old cortina mark 3 my windscreen got smashed but abroad it was a consol not a cortina so I could'nt get a replacement windscreen, so for 3 months i drove around with no winscreen but while driving i would get the old cheeks flapping above 40 mph but it was fine if openned the rear windows! Got some funny looks driving around Monico with my british plates lol.

hitop, thats what you need.......
and a spoiler........

A high top is a spoiler

Hmmm... interesting that some say a hitop is better, some say its worse (or is that only for side winds) ?
Of course there are also various other factors, as discussed in another thread, to consider when choosing a roof, but as far as aerodynamics go, this is a contentious issue? and Mocki, what sort of spoiler do you advise, ie. where to put it? And I couldn't find the article by kev the rev about cd factors, if anyone else can point me to it, that would be lovely...

See here:
normal van: cw 0.44 X surface 3.06 sqm = cw x A 1.35 sqm
low popup: cw 0.45 X surface 3.11 sqm = cw x A 1.4 sqm
popup with luggage tray: cw 0.51 x surface 3.17 sqm = cw X A 1.62
Dehler high roof: cw 0.40 x surface 3.61 sqm = cw X A 1.44
Karmann Cheetah: cw 0.46 x surface 5.17 sqm = cw x A 2.38 sqm

http://www.t3-infos.de/images/Luftwiderstand_T3.jpg" onclick="window.open(this.href);return false;

So if you have a popup with luggage tray (Westy standard) replace the tray with a spoiler

the under the bumper spoiler greatly improoves handling , and therefore should improove mpg

handling mpg am i on the right forum

wow, so that roof really is useful... found some very cool original pics of it in action here, on http://www.ig-dehler.de" onclick="window.open(this.href);return false;

http://www.ig-dehler.de/Ur-Profi/ur-profi.html" onclick="window.open(this.href);return false;
http://www.ig-dehler.de/Ur-Profi/ca_1985/ca_1985.html" onclick="window.open(this.href);return false;
http://www.ig-dehler.de/Ur-Profi/ca_198 ... sines.html" onclick="window.open(this.href);return false;
http://www.ig-dehler.de/Ur-Profi/Syncro/syncro.html" onclick="window.open(this.href);return false;
http://www.ig-dehler.de/Ur-Profi/ca_198 ... klein.html" onclick="window.open(this.href);return false;

is this roof really the westie standard then, should be quite easy to find one?

No, Dehler has nothing to do with Westfalia (they were originally a yacht builder as far as I know)

Dehler roofs a pretty rare and also not easy to put on, there is some major surgery required to make them fit. (Just hearsay, I have no actual experience of fitting a Dehler roof).

Unless you absolutely need and want a high roof for other reasons, I wouldn't put one on just for fuel savings. They'd be negligible to marginal at best.

Having had The Bus both with and without a hitop and with and without a front lower spoiler I can scientifically say it makes kall difference to the mpg.

BUT the chin spoiler really does help in the vicious front corner cross winds I get on't way to't mill and reduces auto lane change syndrome. Nowt helps with a full side-on cos they have the aerodynamic properties of an outside convenience ... which is after all what it is

Ian.