Just out of curiousity, any of you who have taken the Highmount spoiler off your rides, have you noticed a gas milage increase at all on the highways?

I drive mostly highway, and I would definately be willing to ditch the spoiler if I get another 1-2 mpg going 80 mph on the highway. I want to get rid of it anyway, but this would make it happen faster.

I currently get about 29 mpg at 80 mph.

Thanks.

 

If anything its going to help with your Mpg. It creats an air pocket on the back of the car that allows the air to pass more freely over the car.

 

its been said that it could get better mpg b/c of the pressure that is holding you back from the high mount. the top speed SHOULD increase a little and your mpg SHOULD increase by 1 maybe maybe 2 if your lucky. it also mainly has to do with how fast your driving and your rpms. the mpg difference from 65 on the freeway to 80 on the freeway is a good bit more ....... you would prob get about 30-32 mpg if you were doing 65-70 compared to 80.


this is my wing its a hell of a lot better b/c it is actually more effecient than that high wing, but its not as fancy as the high wing.

 

I had my spoiler off for 2 months , with nothing in its place , just a flat trunk . My gas mileage stayed the exact same .

 

sweet wing pclear

 

you're talking MAYBE a savings of 1 dollar/gas tank filled for one more mpg... i too drive around 80 and get the same results... if you slow it down a little, even to 70-75 you'll get better gas mileage...

 

Ya agreed. I wouldn't expect that you would save anything worth the hastle of removing the wing.

Most of the stories of the wing being removed and mileage increasing are more likely simply the fact that the engines have just broken in more and are simply producing better mileage.

 

its not JUST the mpg that i was talking about tho....... you will get a higher top speed..... these cars (RL ss/sc) were drag limited at ~ 150 mph .......... and it was b/c of that high rise wing. you take that away and either have no wing or one some what like mine that will not cause "drag" you will be able to have a higher top speed.

 

You are right, however if the wing is creating drag (and in turn decreasing top speed) that also means that it is creating downforce. In essence, that is reducing lift on the car and would be making it much more stable at high speeds.

I'd need to see a top speed test with the same car (already broken in) with and without the wing to see if that really holds true. I would expect little difference, maybe 2-3MPH, thats all. And to be fair, you'd need to test both cars on a road course, because I'd bet that the winged car with more downforce puts out faster lap times.

And the wing that is on your car likely does nothing at all. It sits too far under the airflow, and likely is near useless. Having no wing on it would be the same as the one you have. These cars are coupes, not fastbacks. The airflow leaves the rear window at about dead centre, well before it touches the short trunk. If your wing did more than the high-mount aero wing than why do all race cars have high mounted wings??? Because they need to capture the airflow coming off the back of the hood, NOT the trunk.

This picture demonstrates my point:



That car has a very similar shape too it. Your low spoiler on the trunk doesn't affect the airflow over the car. The Cobalt SS' high mount aero-wing sits right in the airflow as it leaves the roof of the car. Putting a lower wing on may reduce drag, but it is not a more efficient design, because it serves no purpose (produces no downforce).

 

Odd that this post would appear today a I have been wondering this myself.
It has been raining here and I took the opportunity to see what the water would do through the back window and off the wing. I have the lower SS wing. Speed was 100 cnd or 60 us. I got a freind to sit in the back and give me updates. The water flowed off the back window from the outsides to the center and passed along the trunk lid and right under the wing while the spotted water on the top of the wing basically sat there. Some movement but not like what was sheeting off the rear window. Conclusion was that a wing such as pclear9061 was going to be more effective for down force and vehicle stability than the wing that came with my Cobalt ss/nonSC. As for gas mileage and removing the wing, I think it would be negligable.

 

Yeah, RIGHT...

Who told you that load of BS...

 

When I was in California, I had just come out of the rain doing about 80mph. The water that was on my spoiler was streaking back. So it is in the airstream of the car. This not only produces aero drag, but creates downforce making the car press harder on the ground. It shouldn't produce enough to make that much of a difference at these speeds though.

They say every extra 100 lbs. you have in your car roughly equates to the same as spending an extra $0.10 a gallon. I don't think this spoiler creates near that much downforce at 80 mph.

 

Where was that wing, wind tunnel tested?

 

Mythbusters did a show where a pickup with the tailgait up vs the tailgate down and mpg. Everyone thought that the tailgate down would get more mpg because of drag but they were wrong. Actually the swirl pocket of air that was created in the bed with the tailgate up actually made the air flow over the pocket of air/bed better then when the tail gate was down. With the tailgate down the air pushing down on the truck bed actually caused more drag. Not sure if this even means anything, but it kind has something to do with this.... Maybe. All i know is that i wish i got 29mpg on my SS/SC I get an average of about 24.5

 

The "Bookshelf" is purely visual.

 

Newer trucks are engineered to do that. Spoilers on the other hand are designed to create downforce creating drag.

 

saw that show ... the affect of the tail gate up is called separated bubble or locked vortex flow. As the truck gains speed air is forced into a spinning vortex which creates a sort of bubble of air that constantly spins in and out of the truck bed. This forces the new air away from the trucks back end reducing drag.

With the tail gate down the vortex is completely defeated and the air hitting the truck bed increases the drag on the truck. During the show it was determined by the test that this drag was a bad as losing over 30 miles per tank which by todays prices is over 2 bucks per tank.
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While most cars have a costmetic spoiler at the end of their cars, some are there for a specific reason. The purpose of spoilers is to disrupt the airflow that flows over a car whenever it is in motion. In the cobalts corner the rear wing is also known as a airfoil which does increase downforce and because of this also produces drag at high speeds. The wing effectively keeps the back end of the car from rising at high speeds which is a benefit as without it this would cause the car to be very hard to drive at a high rate of speed if the back end is not stable. So basically everyone that is upset about the wing flapping around at high speeds shold be thanking it that it is there ... as a side note the only time I have seen the wing flap like a blanket is at a high rate of speed like at the track which is over 90 at that point.

 

Any thing to support this?

 

sigh, nope. The wing adds more downforce, more downforce will increase high speed stability, will do nothing but hurt gas mileage. Not a whole lot, but it doesn't help it either.

 

The wing on the SS/SC is certainly functional to some degree. Would it make a huge difference in downforce or fuel economy if it wasn't there? Probably not, but it certainly sits in the airflow coming down from the roof.

 

It does more then add downforce. It makes(should make) the car more aerodynamic. By helping the air flow off the back.

 

What about the 2.2's spoiler? Does it have any affect on the physics of the car or is it more for style than the 2.0 is?

 

I like looking at it...

 

Since the 2.2 sits below the airflow it likely only has the affect of less drag at high speeds with a slight affect of down force if any so it is more cosmetic. Without the wing the car will obviously be more likely to be unstable at high speeds and will have less drag.

 

Mythbusters