Chrysler do advise against driving the car over 62mph without the spoiler up.

I do agree, the car looks much better when it’s down, but from a safety stand point, I let it rise and fall as the car determines. The original Audi TTs were recalled and had spoilers fitted because they became unstable at speed. At least we have the option of keeping the car’s lines when parked.

I have seen a Crossfire parked with the spoiler up in town, and I can only think it’s an invitation to chavs to give it a tug.

 

I believe that's the SRT spoiler.

 

There you go - another factor. And let's not forget the magnetism of the north pole! He'd have to get better mileage going north eh? The big magnet where Santa lives is pulling him home...

 

ppro you beat me to the punch, I was going to mention the magnetic pull of the North pole too. LOL.
I was hoping that you would chime in (being an engineer for an aerospace company and all).
I usually refer to spoilers that sit on the surface of a trunk, or hatch and do not let air pass between it and the surface of the cars body a spoiler. If it is perched on top of some sort of support on (either side) of its surface area, then I refer to it as a wing.
I suppose that's why the Plymouth Superbirds, and the Charger Daytonas were called the "Winged Warriors" by all the magazines during their NASCAR days.
Coincidently, in this old thread, https://www.crossfireforum.org/forum...ear+wing+force
in post #40 I used your bowling ball theory.

 

I remembered that thread and knew it would 'strike' a chord with you. <rim shot>

 

We can expect the deployed wing to increase the resistance to forward motion, the higher the speed the higher the resistance. The deployed wing will create a downforce by creating a lower air pressure under the wing, this lower pressure will have a braking effect on the vehicle. The lower pressure behind the car has to be overcome as the higher air pressure in front of the car is trying to push the car backwards. In pyhsics force is generated by using some other force, nothing is for free, in this case we use more gas and that certainly is not free. Mr Isaac Newton had it correct years ago and he just rode a horse.

 

Actually, that number comes from the then DaimlerChrysler press release on the Crossfire and is also in the service and owners manual.

Definiltey 356 Newtons of downforce at 80mph but I did do a conversion error in my original post, it should be 40lbs not 80.

 

And don't forget the alignment of the planets. Jupitor being aligned with Mars will certainly drop it 1 or 2 mpg.

 

Thanks, that spares a major whipping...

Also, it does not appear in the 2004 US version of the owners manual. Thanks for playing. Here's the FSM entry...



Any more dis-information...? Like for example, the manual is the old version before the deployment and retraction speeds were modified - looks like engineering screwed up and didn't update this page in the manual.....

 

Well, if everybody in the world used metric, there wouldn't have been any errors, I posted 356 Newtons even in my first post.

Errors or update omissions like these are a dime a dozen in car manuals. The '08 300C manual has a features listed that didn't exist until a recent software update.

 

For the wing to produce a down force it will have to produce lift. Our wing is "upside down"; thus the lift produces a down force. The amount of lift increases with the square of speed. Thus the faster we go the more downforce.

A wing cannot produce lift without creating drag. The drag from the wing has two components. One comes from producing lift and is called induced drag. The other is just "regular" drag that comes from anything being pushed through the air (called parasitic drag) and depends on the aerodynamic shape.

I know way too much information....

 

On the contrary MBD, perfect explanation. Induced drag, regular drag, parasitic drag all sound like gas mileage thieves to me, and of course, a "performance" robber as well.
Makes me wonder how much faster an SRT would be (in the 1/4 mile) if you removed its wing.
I don't mind going 30 miles further per tankfull keeping my wing/spoiler down, even though that's not why I shut it off.

 

How much if any would the down force add to rear tire wear? I drive 60 miles/day with 40 on the interstate 75mph+. With the super soft rubber on these high performance tires, it would seem driving with the wing down would have to help.

 

Probably minuscule... any down force on the rear of the car is, for the most part, absorbed by the suspension I would think. The torsional forces (and weight of vehicle) are just so much greater than a little down force. Maybe over life of your tires, you may save a few hundred miles.

 

What a drag

 

I tried this to test the diff between pure gas and the 10% ethanol blend most places sell and I got 28.5 making the same 22 mile trip twice a day until the gas got low on the 10%, and to my amazement I got 27 making the same trip using pure gas I did it twice to make sure almost all ethanol was out of the system but still pure should be better.

I drove each day at approx 60 MPH with the spoiler down, windows rolled up and using A/C. also I did not wash it prior 2 weeks prior to starting the test to eliminate that. because I get 29 or so after a good wash and wax.

 

who cares about gas mileage...have fun. If you're worried about MPG, get a hybrid (and sign away your manhood/womanhood).

 

According to a force conversion chart you were correct at @80 lbs. of down force. Just my .02$

Link-http://www.sengpielaudio.com/calculator-forceunits.htm

 

I'm not sure that would be a good idea. That little motor and gear set is only good for so much force. They have it deploy before the down force gets too high to keep the mechanics of the wing small enough to fit in the small space. I would be a little nervous at making it lift 40 lbs by waiting to deploy at 80MPH.

 

I'll tell you what, I'll let everybody know as soon as my wings motor "burns out" after I open it once too often at some super sonic speed.
But it's been working fine for the last 2.5 years, (and 25k miles) where it seldom goes up at any speed lower than 80mph.
Stay tuned.