Aerodynamic panels, questions/ideas for improving CD and mpg of 6g Options

[ricochet1490]

Has anyone ever heard of addition panels to improve the coefficient of drag (cd) of our cars? Sites like ecomodder have all the people making stupid looking stuff to gain mpg, but imo our cars look too good for that to happen. So I was thinking, what if we made panels that either A) looked good on the car, or B) couldn't be "readily seen" - aka made out of lexan or something.

Any Thoughts, ideas? I think if we could shape some clear panels to deflect air around our bucket head lights, and some to keep the air off the spoiler (but still using the spoiler for mounting/looks), we could probably gain at least a few mpg. It might be worth looking into if some cheap lexan could be found.

[stephen_lee]

underbody panels would be the first thing id look into. really thin aluminum would deflect the wind and keep the weight down, plus protect the underbody from elements (not much for collision as theyd have to be thicker = weight = loss in mpg)

[ricochet1490]

underbody panels would be the first thing id look into. really thin aluminum would deflect the wind and keep the weight down, plus protect the underbody from elements (not much for collision as theyd have to be thicker = weight = loss in mpg)

That has crossed my mind as well. Its not like the underside of our cars are extremely rough anyway, but I think if we made an underbody panel that was "dimpled" like a golf ball then we might be ahead. The dimpling creates a turbulent boundary layer of air(which is why golf balls are rough), and as you can imagine, air sliding past air is less friction than air past metal. Wonder what $$ would look like on that....

[stephen_lee]

im thinking more of the engine bay and over the gas tank/spare tire well. pretty rough areas IMO. and u can make that effect with... a hammer lol

[ricochet1490]

The engine area is pretty rough for sure as is the spare tire, just doing those would probably save on $$ and weight.

On a side note I found myself looking for a "facebook" like button on your previous comment lol very funny

[stephen_lee]

ballpeen hammer on thin sheet metal would create dimples very well.

and i look for that like button on the forum all too often...

[ricochet1490]

ballpeen hammer on thin sheet metal would create dimples very well.

and i look for that like button on the forum all too often...

haha- but you do make a good point. a decent break could probably bend the aluminum where you need it to be, a drill for the holes, but I think I would want some kind of "template" to get even dimplage on it. something with maybe 6 even hemispheres that could be pressed into the aluminum (that is of course if I ended up making a lot of them for people on here in the very distant future) . I know you'd never see it, but it helps to look good. lol

[stephen_lee]

im really not sure what the gains in mpg would actually be, and its really only on highway use that youd see it as well

[SwissFerdi]

One of the rarer Celica parts is the set of clear headlight covers. I imagine they smooth out the front end quite a lot.

[stephen_lee]

I'd like to see a set of those

[azian_advanced]

some GM cars use front air dams mounted under the radiator support (where it's barely noticeable) to reduce drag. also lowering the car will also help. but putting dimples on panels won't do anything noticeable. and stephen_lee is right, improving aerodynamics is only worthwhile if you do a lot of highway driving. if that's the case, you should look into getting low rolling-resistance tires.

[BonzaiCelica]

pics moved to second page

This post has been edited by BonzaiCelica: Dec 30, 2011 - 1:55 AM

[ricochet1490]

^^ now see that's what I was talking about. The headlight covers I bet would be a worthwhile investment as far as aerdynamics is concerned. But the thing of it is, right now I AM doing a lot of highway driving. 1000miles every ten days with about 85% highway.
But I was thinking about some sort of air dam, again made so that it looks good, but my fluid mechanics class is screaming in my ear right now lol. I have to think that the aerodynamic changes would HAVE to be worth at least 1.5-2 mpg. If we reference the mythbusters episode (not where the idea originated but a good example) of when they added clay to the car and then dimpled the clay. They saw a jump in mpg from something like 26 to 29. Now obviously they did the whole car with the exception of the underside, this would just be the underside, but the point is the same.

Using the equation Fd=.5*p*v^2 * A * Cd found here http://en.wikipedia.org/wiki/Drag_equation - And assuming this page is correct http://en.wikipedia.org/wiki/Automobile_drag_coefficient , our cars have a Cd of .32.
And then knowing how Cd is calculated from the drag equation wiki and the Moody diagram found here http://en.wikipedia.org/wiki/Moody_chart . The Fd COULD be significantly affected I think.

If we take for instance the frontal area of our car, estimated to be about 18.84 sq ft. - found here http://www.newcelica.org/forums/showthread.php?t=263442
a velocity of 55 mph, the p(density of air) at 72 deg F with a .32 Cd........ 55mph =24.59 m/s...... 18.84sq ft = 1.75 sq. met. .......... 72F = 20C so p = 1.204 kg/m^3

Fd = 203.845 N at 55mph If we reduce the Cd by even .02 so our new Cd is .3 our new Fd is 191.1. This may not seem like much but it's a difference of 6.25%. Which SHOULD correspond directly to the car not having to work as hard to push through the air. does this mean a 6.25% increase in mpg? maybe, maybe not, but even at 3.125% increase at a standard of 30mpg means a 1mpg increase to 31. All 6.25% gives us nearly 32 mpg. Anything beyond a .02 change could be really significant. Significant enough to pay for itself in a year? who knows- i don't really care to do the calculation right now.
To me the reduction in weight only serves purpose for accelerating type driving. If on a FLAT highway, your car doesn't care if the back seat and speakers are in the door or not. (also proved by Mythbusters episode on dimpling with clay.... that car gained 400 lb because of the clay and on flat ground got better mpg)

Sorry if I went over anyones head, but my engineering brain was screaming

Also I kinda want to relate this to the other topic, of which you may or may not have seen, hence my reference of the weight. http://www.6gc.net/forums/index.php?showto...mp;#entry928916


This post has been edited by ricochet1490: Aug 15, 2011 - 4:43 PM

[azian_advanced]

front headlamp covers will only increase fuel economy by about 0.2 mpg. this was tested on a Renault LeCar back in the 70s. (Source) If you read the article, they also test the same car with sideskirts, with and without an air dam, as well as adding an air dam on top of another (double air dam lol!). they concluded that a single air dam (4" in height) gained an extra 1.0 mpg and the double air dam an extra 0.8 mpg more. i've created a slideshow for a small presentation i did last year on this same topic if you want to have a read (link - password: 6gc).

[BonzaiCelica]

wow there ricochet. You lost me. To technical I'll say and a lot of equations.

I was also thinking that with my gt4 bumper it has a lot of openings on the front. Maybe some way to close the bottom section off, where the foglights are, for track cars??

One thing I'd like to see, is put the gt4 riser blocks on my car and buy the oem replica roof spoiler made by vincent doggy and go do a windtunnel test with those headlights covers. Just to see how much downforce the rear spoiler gets. And then swap it out for the TRD Spoiler.

[OOBE]

The engine area is pretty rough for sure as is the spare tire, just doing those would probably save on $$ and weight.

On a side note I found myself looking for a "facebook" like button on your previous comment lol very funny

That made me lol.

[Neon90424]

just drive behind an 18 wheeler lol

[stephen_lee]

just drive behind an 18 wheeler lol

drafting FTW. i gained about 3 mpg for this

[nics]

just drive behind an 18 wheeler lol

drafting FTW. i gained about 3 mpg for this

Works for me all the time

[Neon90424]

drive behind an angry suv driver aswell plenty of caddies with people rushing like they missin out on the birth of their child

[ricochet1490]

drive behind an angry suv driver aswell plenty of caddies with people rushing like they missin out on the birth of their child

HAHAHAHA - lookin for that FB like button again. We had a suburban at one point and from drafting a truck we got 26 mpg out of that thing lol.

[ACCELICA]

I'm pretty active on ecomodder and definitely one of those freaks who drives around with plastic all over my car to get better MPG. But I agree the celiac is too pretty to do that to. I have a GT convertible that I keep covered and take out once a week for fun. My daily driver is a geo metro that looks like a spaceship but gets around 50mpg. It's weird to say but it's actually as much fun of a car in a totally different way. With the Celica all my mods are for style or performance, with the geo, all the mods cost next to nothing and they are only for function and economy. At any rate here are some things that might be interesting for this discussion.

The three mods I would recommend most for saving gas without sacrificing image are:
1) Grill Block or partial Grill Block. The front bumper openings are designed for the worst case scenario (towing uphill in the desert) but under less stressful situations you don't need nearly that much air going into your engine bay. Think of pushing an open cup through water, that's what your bumper mouth is doing to the air. You can block a good portion of the grill and it forces air around the car with much less drag. Best way to do it is is install some instrumentation to monitor your coolant temp (a scanguage II would work) then block some of the grill with cardboard. Keep driving normally and blocking more of the grill until you see the temp rising then back off a bit. This mod also functions to help your car get warmed up quicker and it is most efficient once warmed up. Once you find the right amount to block you can make something pretty like a colored plastic block with home depot mesh across the whole bumper gap to hid your partial block.
2) the belly pan. Our cars are smooth and pretty on the top and sides but under the car is all kinds of stuff for air to get snagged on. For the geo I just bought a 4x8 sheet of coreplast, trimmed it to shape and mounted it under the car. This can be very effective. The other way to get the same effect is install a front lip that extends as low as your lowest hanging suspension, spare tires, whatever hangs down.
As far as dimpling this... Air behaves weirdly and in many cases the air under the car gets pressurized because the bumper pushes a good portion of the air down and the rest goes over the car. when incoming air hits the pressurized air a lot of it swerves left or right toward the wheelwells. It's weird I've seen it in wind tunnel smoke tests. That makes me think that the dimples may not be as effective on a belly pan.
3) the BIGGEST change you can make is driving habits. The Scanguage is awesome, it plugs into the OBDII port and gives you instant readings for mpg rate as well as avg mpg for the trip. It's like a video game trying to set a high score and you can adjust your driving to get the most significant gains.

There's other things of course, the geo has a kill switch so I coast with the engine off a lot but our celicas would lose power steering and possibly brakes so that might not be a good idea. Pulse and glide is a counterintuitive driving method that can save you a ton of gas. It works like this:
Say you get 22 mpg going a steady 55
You could drive for 55 miles and get 22 mpg
now say you drive that same 55 miles constantly flooring it to 60 then putting it in neutral and coasting down to 50
Assume it takes the same amount of time to coast down as it does to accelerate (I'm sure our fast cars would actually coast longer than the acceleration, but for easy math lets say it's equal)
Now say you get only 10mpg when you're pedal to the metal, BUT coasting in neutral your car is at idle and probably gets 50mpg.
So in 55 miles you would spend 27.5 miles getting 10mpg and 27.5 miles getting 50MPG
Average those together and you get 30MPG
And because your average speed between 50 and 60 is 55 it takes you the same amount of time.
You win 8mpg!

The real numbers might be different but the concept actually works, its so weird but try it, you might be surprised.

btw what on earth is making you drive 1000 mi / week?

[nics]

Ahh ecomodder!! That site gave me wonders on how to get good fuel economy.

Driving with load would be helpful as well. Slow down uphill, coast on downhill!

[yellowchinaman]

Not really eco but better air flow.
My mods consists of:
custom full rear diffuser, custom full front end splitter undertray, full under mid panels.
Loads of Carbon and FRP replacement body panels to loose weigh and maybe blanking out my 2 high beams but only after finishing combining the headlights into the 2 outer ones.

[ricochet1490]

@ ACCCELICA
Thanks for the info man! I've actually scoured that site a lot but always wondered what would actually be best for the car. I just bought another one of these things and it's getting built from the ground up with cool/gas milege mods that will look stock for sure. And that pulse driving thing.... wow, yea, very odd in deed.
But i'm driving 1000mi every ten days because i'm currently about 180mi from home working at Honda until I go back to school. 360mi round trip one weekend, 40 mi. driving at home during the weekend, 100mi to work and back during the week plus another 360 round trip the next weekend and another 40 mi driving around. The cycle then starts over at 100 mi during the week, but thats nothing compared to the rest of it haha

Not really eco but better air flow.
My mods consists of:
custom full rear diffuser, custom full front end splitter undertray, full under mid panels.
Loads of Carbon and FRP replacement body panels to loose weigh and maybe blanking out my 2 high beams but only after finishing combining the headlights into the 2 outer ones.

Have you seen any improvement on mileage?. I'm thinking you should easily see over 31 regularly assuming 5sfe/5spd

[yellowchinaman]

Dont know yet becasue my engine is out and the car's not ready yet.
Before I was getting around 30mpg anyway if I was driving without a heavy foot. Thats after a really good service.

[ricochet1490]

Dont know yet becasue my engine is out and the car's not ready yet.
Before I was getting around 30mpg anyway if I was driving without a heavy foot. Thats after a really good service.

Wow, I have never got that. i've got a 5s auto and with a slightly heavy foot i'll see 28.xx sometimes as low as 26.xx 30+ is 90% highway at 70 flat if I'm lucky

[BonzaiCelica]

vincent's doggy's underpanel is high quality no doubt as some pics that culpable posted on the install. But how about making something of a cheaper material solely to providing less drag on the front under part of the car??? fiberglass was mentioned before or something of plastic similarities... http://www.youtube.com/watch?v=qS8sDkjk0GM



also reposting this pics





whatthe!!


This post has been edited by BonzaiCelica: Dec 31, 2011 - 4:43 PM

[RobbMeeX]

I am also more active on Ecomodders. So far I've added a partial grill block, front belly pan, rear pan from suspension to the bumper, and lastly, I covered up where the downpipe comes past the subframe. Its hard to tell now that its winter, but last tank had me at constant 32mpg. I use coroplast sheets I got for free from a sign place. 1/8" is plenty thick. If you block the grill, you can use flat pieces with a round cut to match the edges pretty well.

[richee3]

I got 32 mpg without any of that work...

[Tigawoods]

i want these. where do i find them?

[Neon90424]

those a pretty rare headlight covers...

[ricochet1490]

I got 32 mpg without any of that work...

you also live in the FLAT land. Where I am I have nothing but ^^^^ mountains. I've been thinking about doing some aeropanels myself.

What doyour panels look like on the car?

[Tigawoods]

those a pretty rare headlight covers...

i would really really like to have them. price is of no concern

are they toyota dealer? or aftermarket company?

This post has been edited by Tigawoods: Dec 31, 2011 - 12:51 PM

[Neon90424]

Headlight Covers


Note: Made of durable acrylic.

Part Number: 08814-14020C

hope that helps sumhow

This post has been edited by Neon90424: Dec 31, 2011 - 1:55 PM

[BonzaiCelica]

those a pretty rare headlight covers...

i would really really like to have them. price is of no concern

are they toyota dealer? or aftermarket company?

aftermarket I suppose.... custom made ones and then a group buy???



If you take a look here you can see the headlights bulg out in a circular shape more than needed. This would affect airflow a bit. It would be best to make them as flat as possible like that of the headlights covers on the orange wilwood celica.



This post has been edited by BonzaiCelica: Apr 26, 2012 - 8:47 PM

[BonzaiCelica]

I am also more active on Ecomodders. So far I've added a partial grill block, front belly pan, rear pan from suspension to the bumper, and lastly, I covered up where the downpipe comes past the subframe. Its hard to tell now that its winter, but last tank had me at constant 32mpg. I use coroplast sheets I got for free from a sign place. 1/8" is plenty thick. If you block the grill, you can use flat pieces with a round cut to match the edges pretty well.

Can we get some pics please??

[Tigawoods]

im making a wtb thread. I havent wanted anything so badly for my car since the diffuser.

[SwissFerdi]

Ja Mike, they're pretty nifty. I'd like a set myself, as I imagine it would provide a tangible aero bonus.

[RobbMeeX]

Can we get some pics please??

Sure! Let me take some...


Part of the front


Thats the rear.

I'll take more and get some better ones.

This post has been edited by RobbMeeX: Jan 13, 2012 - 3:35 PM

[ricochet1490]

^awesome so far! So that right there really provides that much of a benefit??! wow

[BonzaiCelica]

nice entry on that piece guy ^^.

I would like to replicate vincent doggy's C-one underpanel. Its very good for those who are doing rally and need the extra protection for the oil pan and downpipe. Its quite heavy in my opinion adding about 18 pounds to the front of the car of an already heavy front end 6gc isn't so good. So how about making it out of fiberglass or some sort of a plastic. This way it would be cheaper.....



of course we are still waiting on this but no rush. As I"m sure this product will be pricey as R & D is being implemented

http://www.6gc.net/forums/index.php?showtopic=80790

This post has been edited by BonzaiCelica: Jan 13, 2012 - 6:42 PM

[RobbMeeX]

Thanks folks. Its not near done. Those things hanging down are Prius tire spats I had lying around. The front covers from the bumper to bout half way under the oilpan. The rear attaches to the threaded holes in the subframe and goes back to the brackets attached under the rear bumper. I'm planning a full exhaust tunnel with aluminum around the cat to avoid containing too much heat. The coroplast was scraps from a sign shop. I'm gonna add strakes when I close up the rear. I also put panels attaching the front and rear lower bars in the rear. Probably useless, but I had time to waste and it can't hurt.

[richee3]

Just our of curiosity, what was your gas mileage before all this work? Total project cost, time, etc.?

Trace, you're just jealous of my flat lands

I see the benefit of the underbody panel like Vince is making and Bonzai posted but I for one just don't see the practicality on a DD. Having to take the whole panel off just to change the oil seems a bit excessive to me, especially only for minimal gains. Track cars are a whole different story.

[Tigawoods]

my experience with my rear diffuser, I noticed that the stability of the car at higher speeds had greatly increased

I think that, more than mpg gains, your going to find that the car becomes more stable with the addition of aerodynamic underpanels.

[Neon90424]

Just our of curiosity, what was your gas mileage before all this work? Total project cost, time, etc.?

Trace, you're just jealous of my flat lands

I see the benefit of the underbody panel like Vince is making and Bonzai posted but I for one just don't see the practicality on a DD. Having to take the whole panel off just to change the oil seems a bit excessive to me, especially only for minimal gains. Track cars are a whole different story.

put a big hole in it?

[RobbMeeX]

Just don't be lazy and remove it when you change your oil. Change your oil every 5000 and how often is that?
I originally got 28mpg with a cracked exhaust manifold. Now, replaced, with a front undertray I get 31. I'm gonna replace my oilpan gasket then add a panel under the pan. I've got about 6 hours or so in it so far and free materials. The money you save in gas will pay for all of it given enough miles.

[richee3]

Just don't be lazy and remove it when you change your oil. Change your oil every 5000 and how often is that?
I originally got 28mpg with a cracked exhaust manifold. Now, replaced, with a front undertray I get 31. I'm gonna replace my oilpan gasket then add a panel under the pan. I've got about 6 hours or so in it so far and free materials. The money you save in gas will pay for all of it given enough miles.

5,000 miles? Every 2 months or less for me. I see too many oil changes to add unnecessary complications on a car with no performance mods beyond the BEAMS. 3 mpg from free materials is a good score though

This post has been edited by richee3: Jan 22, 2012 - 12:33 AM

[yellowchinaman]

here's something we've made for our sponsored Gen 5 track car and this is a proper under tray.

[BonzaiCelica]

cool cool, now making some for the 6th gen

[BonzaiCelica]

bump?!

[Akirad1]

just swap a VW TDI and you will get 45MPG and 150FTLBS of TQ, lol
but the under body panels are prolly the best to go and remving someof your interior lighter more MPGS

[Box]

I really like the light covers. Would like to have a set. Reminds me of the early Z cars a little.

[BonzaiCelica]

those a pretty rare headlight covers...

i would really really like to have them. price is of no concern

are they toyota dealer? or aftermarket company?

aftermarket I suppose.... custom made ones and then a group buy???



If you take a look here you can see the headlights bulg out in a circular shape more than needed. This would affect airflow a bit. It would be best to make them as flat as possible like that of the headlights covers on the orange wilwood celica.

I really like the light covers. Would like to have a set. Reminds me of the early Z cars a little.

what the name of that company that makes the body kits EUROU I tried searching them up on google but had no luck

[delusionz]

yeah i ditched some of the factory plastic undercovers as i change my oil once a month, but i'd like a proper panel like this, something with a quick-release mechanism would be good too, otherwise i'd use bling bling cap screws which are even more fiddly than bolts

[marinos]

those a pretty rare headlight covers...

i would really really like to have them. price is of no concern

are they toyota dealer? or aftermarket company?

aftermarket I suppose.... custom made ones and then a group buy???



If you take a look here you can see the headlights bulg out in a circular shape more than needed. This would affect airflow a bit. It would be best to make them as flat as possible like that of the headlights covers on the orange wilwood celica.

I really like the light covers. Would like to have a set. Reminds me of the early Z cars a little.

what the name of that company that makes the body kits EUROU I tried searching them up on google but had no luck

I guess you looking fro this

http://www.aero-eurou.com/product/toyota/celica_gt4.html

Hope I have helped.

[Lil-Joe101]

I know adding a front splitter makes a big difference, even if ur not making big numbers, u can still feel it.

[Special_Edy]

All this talk of dimples, something else that improves airflow is small fins running the length of a panel. You see them on the wings of airplanes sometimes. Probably you would want fins that would be under an inch tall at least a couple feet long running under the car. Unlike the dimple idea, they would try to straighten the airflow as it traveled under the car thus reducing turbulence.

Run skinnier tires with higher pressure and less rolling resistance, at the cost of traction and ride comfort they would improve fuel economy. And then you would want to fabricate a cover for the wheel wells. You could cover the entire rear wheel because it doesnt turn. Your goal would be to have as little gap as possible around the entire wheel( including the undercariage and the front/rear of the tire).

Anything you can do to lengthen the car will also reduce the drag coefficient of the vehicle. I remember reading somewhere that the optimal length for a car in regards to drag coefficient is 35ft long. So maybe just chopping the top and sectioning the body would be the best way to approach this.

Of course with any modification, your going farther and farther into diminishing returns. The amount of work required will far outweigh the potential fuel savings

This post has been edited by Special_Edy: May 3, 2012 - 4:13 PM

[delusionz]

so just how much acceleration am i losing from having no plastic undercovers?

[Special_Edy]

so just how much acceleration am i losing from having no plastic undercovers?

Theoretically acceleration is increased because you just shaved a half pound of weight off.

The vehicles top speed, stability at high speed, and fuel economy are all adversely affected

[ricochet1490]

unless no plastic covers are creating a parachute effect somewhere.... in which case you maybe also losing acceleration. lets face it, you could lose a 1/2 lb on the car based on whether or not you are wearing jeans or shorts....

Long story short, without wind-tunnel or advanced flow software modeling, it's going to be hard to quantify improvement or problems caused by not having plastic underpanels, and for the purpose of this topic, adding panels to improve (reducing) your coefficient of drag (CD).

The simple F=ma is what you are looking at because the F is actually summation(F), where all of the forces acting on the body, in this case the car, are added up. So if your Fd(force drag) is increased, that means your forward force vector is smaller. With that being smaller, acceleration drops.... but it likely only becomes a problem at highway speeds. 0-45 difference is negligible with or without plastic under covers.....

[199celica]

i know this might be a little off topic of what you guys may be talking about but what about the proper use of a vortex generator i haven't seen one 6gc with one or a weekend warrior track car with a proper vortex generator from what i understand this helps create more downforce on the rear end but gets rid of drag due to air moving around air pushing the car down i'm not sure if im close to the proper theory behind it but i don't know just a thought i had twittling in my mind.

[delusionz]

so in other words, my best run on the day i got 13.26 i may have gotten 13.25?

[ricochet1490]

on the track... yeah... there is more variation in driver input than the plastic underpanels provide. However extended DD work would likely yield results... assuming you keep it out of WOT


What is this vortex generator you speak of?

If it does what I think it does it makes sense. If you could counteract the eddy currents and vortexes caused by the low pressure formed behind the car, you could really increase fuel economy for sure.

Any links?

[199celica]

this is the vortex generator i speak of it directs the current to swirl around the back of the vehicle to push down on the rear of the car if placed property and if faced in the correct direction most people put them on straight it is supposed to go / / / \ \ \ or something of that sort i don't remember correctly it was in my class at UTI haha shows how much i learned but anyways its supposed to cause a swirling effect as a truck bed adds but to push down on the back of the car for added traction and stability.

[ricochet1490]

hmmm....

In other news, yellowchinamans front splitter is done, but I might rob his design #2 because of the 1/2 the drag number AND it still increased downforce....

get it broke and welded out of aluminum... ugh yeah!

[ricochet1490]

front headlamp covers will only increase fuel economy by about 0.2 mpg. this was tested on a Renault LeCar back in the 70s. (Source) If you read the article, they also test the same car with sideskirts, with and without an air dam, as well as adding an air dam on top of another (double air dam lol!). they concluded that a single air dam (4" in height) gained an extra 1.0 mpg and the double air dam an extra 0.8 mpg more. i've created a slideshow for a small presentation i did last year on this same topic if you want to have a read (link - password: 6gc).

just re-read the source in popular mechanics. Very interesting.

Your link to that file is broken though I would be interested in reading your paper on the matter.... fluid mechanics excite me lol

[azian_advanced]

i keep forgetting to send you that file.. i happen to be at work each time i remember.

[azian_advanced]

front headlamp covers will only increase fuel economy by about 0.2 mpg. this was tested on a Renault LeCar back in the 70s. (Source) If you read the article, they also test the same car with sideskirts, with and without an air dam, as well as adding an air dam on top of another (double air dam lol!). they concluded that a single air dam (4" in height) gained an extra 1.0 mpg and the double air dam an extra 0.8 mpg more. i've created a slideshow for a small presentation i did last year on this same topic if you want to have a read (link - password: 6gc).

link fixed

[ricochet1490]

This is what I see on my screen when I click the link from my computer