How bad will a wing hurt fuel milage???

[LWB053]

I think it's safe to say you'll lose 1 or 2 MPG with a wing. If you like the looks, go for it. You'll still be getting > 40 MPG, and you'll have a car that you like.

I personally don't care for the looks of them, but then again, if everyone had their car looking as good as mine, the roads would be quite boring, now wouldn't they?!
/images/graemlins/grin.gif /images/graemlins/wink.gif

 

[spinfire]

[ QUOTE ]
FowVay said:
Now if I can only figure out how to get my car to rev at nearly 6300 rpm so I too can go 130 mph and gain the full benefits from these stylish mods.... /images/graemlins/grin.gif

[/ QUOTE ]

6300? Gee, I can't wait to rev that thing up to 11 o'clock!

 

[fixedXgear]

i don't know how bad a wing will hurt your mileage, but that eBay link is-hands down-the funniest auction i have ever seen in my entire life. i am still laughing, just thinking about it...
redeems this whole thread.

 

[rwolff]

[ QUOTE ]

I've never understood putting wings on passenger cars. You just taxi with the dang things...What's the point?
Want wings? Get a plane.


[/ QUOTE ]

[English upper-crust accent]I say, old chap, you may not realize it but all stock VWs have wings. Without wings, they wouldn't be street legal, because the tyres would stick out beyond the sheet metal. [/English upper-crust accent]

For those of you not familiar with differences in the English language between here and "across the pond", their "wing" is our "fender". /images/graemlins/grin.gif

 

[03GOLFTDI19]

I have actually hit 131 /images/graemlins/smile.gif no bs either....

i never said if i wasnt on a downhill slope..hehe...and 131 is 5th gear redlined so i let off soon as i got up to that speed, no need to torture it for a long time...

 

[03GOLFTDI19]

[ QUOTE ]
spinfire said:
Now, this is a ricer.

Be sure to look at all the photos and definitely watch the drag racing video. I was laughing so hard it hurt for 5 minutes straight.

[/ QUOTE ]

I just looked at that car...lmao...ok the bid is at 15k ***?!?!?! are they buying it from themselves for the fun of it?

 

[mrGutWrench]

[ QUOTE ]
03GOLFTDI19 said:
(snip) I just looked at that car...lmao...ok the bid is at 15k ***?!?!?! are they buying it from themselves for the fun of it?

[/ QUOTE ]

__. 15K for a 15 year old, junked-up Honda. The joke gets funnier all the time -- now it's pretty much as hilarious as a wing on a 90 HP VW (although I have to admit that the dragstrip video is even funnier than the wing).

 

[ruking]

Why would you want to install a wing? Your Jetta has a co efficient of friction of .30 which is the same as a Z06 Corvette, which is about the lowest coefficient of friction on the stock market. So you decrease fuel consumption by 1-3 mpg, add cost, weight and add on drag and for no performance gain except for MAYBE advertised downforce at 110 mph? Without a further min 10 hp/ft#'s of torque gain, you have just decreased your top end speed.

 

[mobe]

Not as funny as the '87 Ricer but still pretty laughable. It looks like something from a Power Rangers show.

 

[ruking]

Kind of makes you wonder why someone would want to sell this one of a kind art object!!?? /images/graemlins/grin.gif

 

[GotDiesel?]

[ QUOTE ]
Papachristou said:
maybe that is your problem, damn cessnas are POS anyhow, go TURBINE or bell 206 (it doent have wings plus taxis and flys faster than your C150

[/ QUOTE ]

My Cessna 150 will taxi just fine up to about 50 mph or so--then it doesn't want to stay on the ground any more. (Maybe it needs another wing /images/graemlins/wink.gif ) Dunno why you think of Cessnas as POS but that's another thread I guess.

Bell 206's actually have two wings... they just happen to be spinning overhead. They don't taxi, either.

Turbines are fine if you can afford to burn >20 gallons per hour. I can't.

 

[Pressurized]

The decklid "wings" may actually help your mileage slightly. The ones you reference are close enough to the decklid that air does not flow underneath as you would expect - so they do not function as wings. Rather they work by raising the effective height of the decklid in relation to the rear backwindow header.

However without testing them in a windtunnel or some very careful road testing, its a crapshoot as to what the rear spoiler or "kicker" will do. These guys who sell this stuff are just eyeballing them. Some are made from molds "reversed engineered" from other production cars.

The ones that attach to the backglass will most likely increase your aero drag.

Bolting on a rear device, without adding a front airdam can unbalance the car.

Radio antennae rarely add any drag, with the exception of the squat thick ariels that VW's use. Again, its a crapshoot. The Nascar teams played with their radio antenna on the roofs and sometimes could reduce drag slightly.

 

[ruking]

[ QUOTE ]
Pressurized said:
The decklid "wings" may actually help your mileage slightly. The ones you reference are close enough to the decklid that air does not flow underneath as you would expect - so they do not function as wings. Rather they work by raising the effective height of the decklid in relation to the rear backwindow header.

However without testing them in a windtunnel or some very careful road testing, its a crapshoot as to what the rear spoiler or "kicker" will do. These guys who sell this stuff are just eyeballing them. Some are made from molds "reversed engineered" from other production cars.

The ones that attach to the backglass will most likely increase your aero drag.

Bolting on a rear device, without adding a front airdam can unbalance the car.

Radio antennae rarely add any drag, with the exception of the squat thick ariels that VW's use. Again, its a crapshoot. The Nascar teams played with their radio antenna on the roofs and sometimes could reduce drag slightly.



[/ QUOTE ]

The only way it can decrease drag or help your mileage slightly is if it makes your car approach .29 coefficient of friction or less!!??(The VW Jetta is listed at .30 coefficient of friction.) It also adds weight unless you get rid of corresponding weight from somewhere else. Added weight helps neither mph, mpg nor power.

 

[snoopis]

[ QUOTE ]
FowVay said:

Now if I can only figure out how to get my car to rev at nearly 6300 rpm so I too can go 130 mph and gain the full benefits from these stylish mods.... /images/graemlins/grin.gif

[/ QUOTE ]

I'm assuming you were half-joking with this statement. My stock tdi runs right around 4200rpm at an indicated 120mph on level ground... of course, by the time I get to 120, I've crossed two state lines. /images/graemlins/crazy.gif



As for the "wings" I don't think you should worry about it. It will make a difference in mpg, but not much. Probably not any more difference than changing your tire pressure by a couple psi. And that's highway. Around town, you'll never notice. Riding around with a vented tank (extra weight from more fuel) will effect your city mpg more than any wing IMO. Not that I've researched this, nor have I seen any data on the subject... but I do have a BS in Aerospace Engineering, so I think my background of physics and aerodynamics is sufficient to make an educated guess.

-Nick

 

[Pressurized]

Weight effect on fuel economy is way over-rated by most peoples best guessing unless they start with a light car and do a majority of city driving.

Combustion efficiency is the #1 factor in fuel economy.

VW probably underestimates their Cd's slightly. .030 is very good. In real conditions with cross-wind's etc it is higher. Skinny tall tires is the easiest way to decrease fuel usage.

 

[ruking]

[ QUOTE ]
Pressurized said:
Weight effect on fuel economy is way over-rated by most peoples best guessing unless they start with a light car and do a majority of city driving.

Combustion efficiency is the #1 factor in fuel economy.

VW probably underestimates their Cd's slightly. .030 is very good. In real conditions with cross-wind's etc it is higher. Skinny tall tires is the easiest way to decrease fuel usage.



[/ QUOTE ]

I don't know that it is over rated vs already factored in. As you know a 1.8 jetta and 2.0 Jetta and a 1.9 TDI are app the same weight. Combustion efficiency already a given when you go from 32 mpg in a 1.8 to 49 mph in a TDI. But if compare same same, all things being equal and I carried 100 to 200 to 300 #'s more than you, it would be very obvious who would get better mileage, don't you think?

 

[Papachristou]

I dont think the added weight of a 10-20 lb wing (top) that kind of weight comes and goes wtih stuff, fuel, passengers etc) will drastically reduce my fuel mileage, also i am not going for functionality (especially not on a FWD), Thanks for all the opinions, and feel free to add more!

 

[ruking]

I think perhaps you are missing the point. 1. What does drastically mean to you? 2. You might want to do a search on this site where some folks talk about the effects of driving with a bike on a rack and the effect of the rack on mpg. One post I read said with a rack and a bike he goes from 48-50 mpg to something like 37 mpg. With a bike rack it drops something like 5 mpg. So the 10-20 #;s of the bike rack is really not the issue now is it? So if 5-12 mpg is not drastic, I would agree with you, that would not meet YOUR definition of drastic.

 

[GotDiesel?]

A small wing on the trunk lid will not generate the same amount of drag as a bike rack on a roof. Won't generate much down force either, but it may make the trunk lid more likely to close itself.

I remember a fairly droll comment in Consumer Reports once (long ago) about the wing on a Mustang Mach I generating so much down force that it caused the trunk lid to close unassisted, even at a standstill.

 

[20IndigoBlue02]

Anyone remember the SC400? The optional lip spoiler dropped the Cd by about 0.01.

A properly designed spoiler can improve the Cd, keyword being properly.

 

[gdr703]

That would be a spoiler, not a wing?

 

[Papachristou]

SO the top of the backglass spoiler will hurt the most? also the lip spoiler or kicker that i am seriously entertaining is factory on the boras in europe. no air goes underneath it, it just sticks up about 1.5-2 inches from the decklid with a curve to it, i also wonder if it might block the 3rd brake light?
in regards to the bicycle and roof rack, that is very different (in my most huble opinion) than a trunk lid lip kicker/spoiler, that bike sticks way up into the airflow, also if you have a sunroof, oopen it and see how much air you get, a lot, now when it rains, stick your hand out the sunroof, my gets wet quickly, but as long as you are at speed, my back glass takes a while to get wet which suggests there is not that much air coming down it right at the surface, in which my lip kicker/spoiler should not hurt me very bad
and if it does cost 5+ mpg, it WILL come off, hehe

 

[ruking]

Please keep us informed as to what before and after mileage you ACUTUALLY achieve.

 

[Reeder]

[ QUOTE ]
GotDiesel? said:
I remember a fairly droll comment in Consumer Reports once (long ago) about the wing on a Mustang Mach I generating so much down force that it caused the trunk lid to close unassisted, even at a standstill.

[/ QUOTE ]

A few years back Honda had a similar problem with the accessory wings they provided. They fixed it by replacing the deck lid springs with heavier units. This increased the upforce inside the trunk negating the initial effect of the downforce created by the wing. /images/graemlins/grin.gif

 

[Papachristou]

i have to lean into my trunk to close it

this tank of gas i got 750 drivng 65-70 and a little 75 i also had about 60 miles at 80-90 and one hard run through memphis TN if it wasnt for that, i would have easily broke 800 and i filled up 10 miles into the fuel light

 

[LagoonBlueTDI]

I'd skip the wing and just go for a red "Type R" sticker...

 

[Ernie Rogers]

Papachristou,

Do I get the last word? The Jetta has excellent aerodynamic design. The part that makes it work is from the top of the back window (the bend) to the edge of the trunk. Anything that changes the smooth flow along that surface will hurt mpg. I would have to look at a specific wing and the angle it's set at to tell you what the effect will be. Definitely do NOT put anything sticking out near the top of the back window since it will cause flow separation there. Your drag coefficient will go from about 3.0 to about 3.8 if you do that. What does it all mean? Well, you should see a reduction in fuel economy above about 50 mph, more as you go faster. I'm guessing 5 mpg at 80 mph (at 3.8 drag), but I'm guessing. By the way, the New Beetle starts off with a drag of 3.8, so Beetle owners can put on a mongo wing if they want with minimal effect.
/images/graemlins/smile.gif /Ernie

 

[Oldman]

No I get the last word, a rear window wing such as a caracture, and a Zender trunk spoiler will improve CD. I have both and I just got 47 MPG last fill up with 17x8 rims and the A/C cranked up, all city driving.

The rear glass is too steep so the rear window wing keeps the air from being turbulent, same as the rear trunk spoiler such as the image posted on the initial thread.

http://www.freedomdesign.com/Merchant2/m...ory_Code=jetta4

http://www.freedomdesign.com/Merchant2/m...ory_Code=jetta4

I got the Zender trunck spoiler instead:
http://forest.geog.ucsb.edu/vw/jetta.html

So if you buy correct, you can have your aerodynamics and your looks. But PLEASE no ricer wings.

 

[Papachristou]

I hate to knock you, but i dont think that wings and spoilers have that much effect with city driving, and i really dont see how you could get 47mpg with 17's and city driving

now the last poster was saying something about the top rear glass spoiler would cause seperation and therefore decrease the milage, please explain

 

[Oldman]

and if I told you during the fall I'll crack into the 50 MPG area you would just about drop a load?

IMO, the rear window wing works and looks good, and if it does not work, it still looks good, but there is no way to my mind that it does not work and increase drag. A spoiler keeps the air into boundry contact along the trainling surface, this is what the deck lip and window spoiler do. Check out a Civic Hybrid, 2004 Jetta, both sport some sort of rear deck turn up. Now to the glass spoiler, there are many ero OEM rear glass spoilers, you know the place with unlimited speeds?

Oh I agree that city driving means zero for the spoiler, Did you limit your question to city driving? If 100% city even a huge wing is not going to drop MPG very much. So go ahead and bolt a huge double wing on.

17x8 and MPG, get the correct tire and you will be in the same range, I was at 51.5 on OEM tires, more in the Fall.
Conti Contac eco 225x45 on 17x8 Superleggara. You will be down about 4 MPG from OEM and with some sticky tires (not useful) you will be down 50% more say 6 MPG from OEM. I should add maybe you should change your city? I also wanted to add I run them at 36 PSI but I've gone as high as 51 PSI there is about 1 MPG difference between the two settings but 36 PSI is smoother....