Ok lately I've been thinking of ways I could squeeze a little more fuel out of a tank. Save money and the environment so on an so forth. Now fuel is used to produce power and power is used to push your car forwards. However most of your power ( probably upwards of 70%) while in a steady cruise is used simply to overcome drag. So if we reduce drag we should reduce the fuel required to travel at a certain speed. Also between 60% and 90% of drag is caused by the parasite drag from the wake of the car.

I noticed the other day that some evos have vortex generators along their roof above the rear window. In aviation we use vortex generators to prevent boundary layer seperation which reduces drag (and delays a stall but that's not so important on a car)

So my question is. At the low speeds a car travels (120 or so) would fitting vortex generators gie me a detectable increase in efficiency?

You could always give it a try and see how you go with your fuel consumption. I will point out however that the 3rd gen Magna (sedan) is the most aerodynamic car produced in Australia to this date.

No. Vortex generators on Evos do nothing. They're simply cosmetic.

Yeah pointless exercise. Better off with low resistance Tyres as a single point of improvement for consumption . Also driving style, stick to 80-90 on freeways and economy should be optimal

anyone see the economy testing done by Mythbusters when they used a dimple covered car (like a golf ball design) and acheived a better MPG rating then the same car without. Very intreguiing

Depending on the service history, I have found the follow work well for fuel consumption.

New o2 sensor
New air filter
Change oil and filter to quality components
Change to low resistance tyers

anyone see the economy testing done by Mythbusters when they used a dimple covered car (like a golf ball design) and acheived a better MPG rating then the same car without. Very intreguiing

Very intriguing!! And one more reason whey maybe I shouldn't bother getting my hail-damaged KJ repaired? LOL. Panelbeaters submitted a quote of about $6000- to GIO a day or two before the Easter Break - Insurers not able to tell me today where the claim is at, or when a decision likely to be made.

I may just call them and say "I'll keep the dimples, they save me fuel". I always thought it would be fun to get a hail-damaged car painted to look like either Swiss Cheese, or else the Lunar surface. Never guessed it would also save fuel!

No. Vortex generators on Evos do nothing. They're simply cosmetic.

On the subject of vortex generators...
An autospeed article regarding vortex generators, how they work and subsequent testing of aftermarket fitment.

http://www.autospeed.com/cms/A_3058/article.html
http://www.autospeed.com/cms/A_3059/article.html
http://www.autospeed.com/cms/A_3060/article.html
http://www.autospeed.com/cms/A_3061/article.html

There was another autospeed article regarding the use of an underbody tray to help reduce wind resistance. Can't hurt to try it.

My car came with an underbody tray from factory, pretty much half way back under the car. Didn't notice a lick of difference when I took it off.

yeah the magna has a drag co-efficient of 0.35 i think, i know its very good and better than many sports cars including porshe 911.

Looks like it's time for someone to fire up a CFD program and start entering data!

yeah the magna has a drag co-efficient of 0.35 i think, i know its very good and better than many sports cars including porshe 911.
997s have drag coefficients of .28 up to .32, the GT2 having the worst. Wikipedia also lists the 1995 Diamante (3rd gen Magna) as being .28, that can't be right...

ahh thats it 0.28, i had read the same somewhere else, i think its right, things like the boot sloping back help prevent turbulence behind the car and the steep windscreen angle, plus the curvature of the front. compared to many cars ive driven they are very quiet at 100-120kms. my old isuzu trooper was a shocker , you could feel the wind push when a truck coming the other way came past, and if the wind was against me across driving across the hauraki plains (long straits) i would use alot more fuel.

From memory of reading Mitsubishi press articles and auto reviews, the TE had a Cd of 0.26.

Also, if you want to increase fuel efficiency:
1. Fit lower rolling resistant tyres.
2. Pump them up to at least 36 PSI
3. Monitor traffic when driving. No point in keeping on accelerating when traffic up ahead is about to come to a standstill.
4. Fit spoilers (not wings which produce downforce) to the boot which extends the laminar airflow so turbulence occurs further away from the car.
5. Don't carry excessive amount of stuff in the car.
6. Lose some weight.
7. (This is for the Government): Need better traffic lights which warns when they are about to change (brings me back to the days in Perth when the Kwinana Fwy was being built, they still had traffic lights but had warning lights prior so if you pass it and it has not started flashing then you are able to make it across the lights).

...
7. (This is for the Government): Need better traffic lights which warns when they are about to change (brings me back to the days in Perth when the Kwinana Fwy was being built, they still had traffic lights but had warning lights prior so if you pass it and it has not started flashing then you are able to make it across the lights).
We have some of those in Melbourne (not many though).
Amber flashing lights on a sign when approaching traffic lights (especially when coming off an 80-100kph zone). They start flashing and you know to lift ya foot off the peddle and let the car coast up to the lights (which will be red when you get there). They're a great idea.

So all we need now is a Magna, someone with the ability to make some vortex generators of varying designs/sizes and a wind tunnel? :doubt:
I'm guessing that even if we could design one and prove it did make less drag and the car more fuel efficient, it'd be so minor, we'd hardly notice it.

Here (http://autospeed.com/cms/title_Car-Aerodynamics-Have-Stalled/A_2978/article.html)is a very interesting article on drag coef in the auto industry.

Now I don't know wether to love or hate my aunger louvre but I dragged it around for the whole life of my TE and it still looks OK so it now lives on the KL. Wonder if it helps or hinders the fuel economy. Since it has been constant there is something much bigger causing the 2.5 L/100km increase in the fuel consumption.