I have seen it mentioned quite a lot when people are talking about speeds of 100+mph they tend to say that the Octy should outpull a similarly powered furby because of its low drag coeficient (cD).

Also that the Octy has a better cD than a Volvo T5-R (just an example).

Does anyone know if there is a website where i can compare some drag coeficients of similar cars, e.g. Bora, Golf, BM 3 Series etc.

JD

This site lists them for US cars. Unfortunately it doesn't include any Skodas, but if an Octy is your point of reference, presumably you know the cD already?

http://www.teknett.com/pwp/drmayf/tbls.htm

Hope it's of interest...

EDIT: Just noticed - it doesn't have many new cars on it at all :thumbdwn:

0.28 or 0.29 IIRC. As a reference the Calibra is 0.3

A fabia 5 door hatch is 0.32cd. Fabia estate is 0.29cd

Octavia Hatch and Estate

0.29 vRS

0.30 Classic

0.31 Ambiente, Elegance and L&K

0.32 Elegance 4X4

New Octavia

0.30 Classic, Ambiente and Elegance

Fabia

0.29 Estate

0.31 Saloon

0.32 Hatch

Audi TT 0.32cd

New Golf 0.32cd

I note from DGW's figures that the VRS has a lower figure than the Elegance etc. I would have thought that the addition of the rear spoiler would have increased it? I know its an extreme example but the Escort Cossie goes faster without the big whale tail.

Also, worth considering is the air flow behind the estate.

Has anyone got the figures for a WRX Scoob? A friend of mine works at Prodrive and is often saying how they hate the bonnet scoop because of it's bad aerodynamics. On the WRC cars it is blanked off but Subaru wont let them remove it because of the image!

04 Scooby WRX and STI is 0.33cd

Dont you just love google

Classic 0.35cd

So you take the biggest, highest, housebrick-like octavia, the 4x4, and it has the same CD as the Fab hatch?

Just how badly is the Fabia designed?? Anyone got the Ibiza or Polo cd?

cD is frontal wind resistance IIRC

So you take the biggest' date=' highest, housebrick-like octavia, the 4x4, and it has the same CD as the Fab hatch?

Just how badly is the Fabia designed?? Anyone got the Ibiza or Polo cd?[/quote']

Think polo is the same. Can't find the ibiza.

I note from DGW's figures that the VRS has a lower figure than the Elegance etc. I would have thought that the addition of the rear spoiler would have increased it?

But the vRS also has a front spoiler and less ground clearance which should reduce the Cd figure, although wider tyres will have an adverse effect.

0.28 or 0.29 IIRC. As a reference the Calibra is 0.3

No way! I thought the calibra was 0.27 (the most aerodynamic 2+2 coupe in the world, at the time)?

I had one before the Octy :ashamed:

http://www.martin-tlusty.euweb.cz/htm/CarAerod.htm

This guy hates the new Octavia :confused:

(And it seems the post-facelifted Calibra was actually 0.26...)

cD means nothing by itself.

If you want to compare different cars you must use cda

Coefficent of drag (cd) * cross sectional area (a)

cD means nothing by itself.

If you want to compare different cars you must use cda

Coefficent of drag (cd) * cross sectional area (a)

Agreed,

All things being equal small cars will tend to have higher cd than larger ones, something to do with achieving good laminar flow over shorter lengths of bodywork.

In that sense the Fabia is every bit as well designed (aerodynamically) as an Oktavia - because designers had a harder job to do.

Estates often fare better for similar reasons.

Also bear in mind the space, practicality and versatility of the Fabia for it's size, if it were a 3 door Clio 182 it's bound to be better.

For a small car it's pretty decent I'd say.

With all the laws regarding pedestrian safety it's amazing how the aerodynamics are still kept in the 'good' range

Avoiding stuff like driving at high speed with your windows 'down', sunroof open, roofrack & bike rack have a far bigger impact on the drag anyway

Amazed the lowering of the vRS has that much impact on the Furby though I must admit. The standard Octi vRS seemed like it was still pretty high up when I was parked next to one at 'da Mrs work' - couldn't afford one but it seems decent enough

Has anyone got the figures for a WRX Scoob? A friend of mine works at Prodrive and is often saying how they hate the bonnet scoop because of it's bad aerodynamics. On the WRC cars it is blanked off but Subaru wont let them remove it because of the image!

The Scoop doesn't harm the top speed much but it causes front end lift, to counteract the lift Prodrive have to engineer extra downforce into the front lip spoiler which does slow the car. The big lip spoiler on the P1 just cancels out the lift from the scoop.

The WRC does have a front scoop which is smaller than a WRX and way smaller than the STi. Older WRC Scoobs used to take cold air from the scoop to feed straight into the airbox.

Cheers

Lee