Vortex Generators

Back in the seventies, Valiant advertised their big wagon with an 'integrated wing' on the back. They said this was to reduce the amount of dust entering the cabin via the tailgate. A diffuser?

No mention of anything to do with the amount of juice a 265 hemi sucked, tho'....;)

I seem to recall the tv ads even showed a quasi windtunnel demonstration of the 'laminar flow'....

...seals must've been crook in those days....:D

GQ

Quote:

---

Originally Posted by rjhjstr

Thanks for alerting me to this thread Tombraider.
I do have these vortex generators fitted to my Disco2. As an engineer, I fitted them more in hope than anticipation and as far as fuel economy is concerned that has proven true. There has been so little change to fuel economy as to be unnoticeable. However there is definitely an improvement to the way dust, rain etc gets pulled in behind the vehicle and sticks to the rear window. That has been noticeably reduced.
When I was thinking about these things I did some research on the net and found a couple of articles from Mitsubishi and a Uni in USA regarding the effect of this type of vortex generator on fuel consumption. Both concluded that the effect exists but is small. The USA study on interstate trucks concluded that an underbody deflector to deflect air exiting under the rear of the vehicle up into the area immediately behind the vehicle had a much better effect. I haven't tried that yet.
Incidentally, I made some homemade vortex generators, (copied from the results of the Mitsubishi engineering article not Fuelsavers) and put them on my caravan. Again, I cant see any difference in fuel economy but the back of the caravan stays cleaner.
Russell

---

Thank you Russel, your informed and experienced comments are what I was hoping for.
I may yet decide to try them out for first hand data and effect.
Also to everybody who has contributed to the thread.
Cheers,
Paul. :twobeers::beer:

And thank you Mike, for alerting Russel.

If you want to save 5% on your fuel bill walk to the corner shop once a week for milk.It will do your heart and wallet a favour. Pat

Quote:

---

Originally Posted by Slunnie

C'mon Emerald, give your jack shyte comeback some value by supporting it otherwise it comes across as being uninformed - just make it laymans terms as Bush65 has so that the rest of us plebs can understand it.

---

Ok Mate fair enough...fitting these gadgets wont do anything for you except remove money from your pocket and you wont see a payback in my opinion for the various reasons given in earlier posts.

I cant be more politically correct than that today, it is Monday :)

Emerald

Quote:

---

Originally Posted by PAT303

If you want to save 5% on your fuel bill walk to the corner shop once a week for milk.It will do your heart and wallet a favour. Pat

---

Nearest shop selling milk is 60km away - I'm not sure your recipe is practical for everyone. But you are right - the biggest saving most people can make in fuel is to think carefully before driving anywhere - "do I really need to do this trip? Can I combine it with another trip or simply not do it?"

John

Funnily enough, the recent posts are more efficiently accurate than any 'device'..

I cut my Landy fuel bill (and other items) by heaps.

I walk... and I've re discovered the fabulous Peugeot, my old ex Tour de France pushbike...

which is a total pita:twisted::twisted::twisted:

seriously tho', the highway in the Disco is now about 100km/h, not 120... the tyres are 40psi, no tonnes of junk in the boot and after the fuel dramas around here, i'm back to 7 kilometres to a litre of juice....no more crap on the roof, either....

weighbridge on saturday, me not inside, half a tank of juice, showed the disco was 1.856 ton.

not much more than an (big six) aussie sedan....

GQ

My god! I stripped out a lot of my disco and hit the weighbridge this morning coming up at 2.4T!

TD5, steel bar, winch, sliders, very empty LR tanks and that was it.

Quote:

---

Originally Posted by Slunnie

My god! I stripped out a lot of my disco and hit the weighbridge this morning coming up at 2.4T!

TD5, steel bar, winch, sliders, very empty LR tanks and that was it.

---

Lara....

Comp bar, winch, LR tank, Draws, Fridge, Recovery Gear, Rack, Carrier, Sliders...

2.7t with 1/4 tank fuel and no fat ballast in driver seat.

One effect that they mention the vortex generators have on trucks is that it increases the directional stability of the trailers in a cross wind. Could have benifits on a caravan.

WR.

Quote:

---

Originally Posted by wovenrovings

One effect that they mention the vortex generators have on trucks is that it increases the directional stability of the trailers in a cross wind. Could have benifits on a caravan.

WR.

---

How bloody big are they?