How to decide whether to remove rear spoiler to decrease drag, improve mileage

[Joenavy85]

Originally Posted by cfg83

MetroMPG -

I like these spoilers the most, the "flush-kamm-back" looking ones :

Ford Hydrogen Fusion 999 in grey primer
Autoblog Green — We Obsessively Cover The Green Scene


Hmmmm. In the "grey primer" image, there is a parachute tucked in the back. Maybe they're main purpose is to act as parachute shields?!?!?!?!?

CarloSW2

Cleaner separation for better parachute effect???

[Piwoslaw]

Alfa Romeo 156 (OEM option?)

I can imagine stretching some fabric between this spoiler and the rear pillars/roof and getting an elastic Kammback which will allow the trunk to be opened.

[Wonderjava]

i have a pt cruiser with a rear spoiler, since im not technically inclined im afraid of taking it off for fear of not being able to put it back on if it does help mileage. is there anyone that can tell me if that rear spoiler actually does help on mileage with my particular car or not? im not talking about the little "lip" spoiler, im talking about the actual spoiler that comes off the top back of the car.

[Sven7]

If you could post a side view, telephoto if possible to reduce perspective, we could take an educated guess.

[Wonderjava]

here is a side of a pt with the same spoiler on the back

[aerohead]

Originally Posted by Wonderjava

here is a side of a pt with the same spoiler on the back

The PT is a square back and does not generate lift so I'm guessing that the spoiler is serving a styling function,it keeps a little sun out of the car in summer,it may be creating a jet of air to mitigate back-soiling of the rear windshield,and in a 4-season environment,if the snow is heavy enough,it might provide a protected clear slit underneath for rear vision if snow is trying to build up on the glass.
Dimensionally,it's not large enough to significantly impact mpg.Just an opinion.

[Wonderjava]

so in other words your opinion is no it should stay where it is?

[Sentraguy]

I'll be starting the testing of one of the flush mount kammback style spoilers tomorrow. I went to the store tonight and am not sure, but almost felt a difference in coast down time. We will see tomorrow. Here is a pic of my version. More to come later

http://i1255.photobucket.com/albums/...5-12_18-30.jpg

[Frank Lee]

If it was my car, I'd try it without and try to see if a trend shows up in the gaslog.

[MetroMPG]

Chrysler fitted the later PT's with a small "lip" spoiler on top of the hatch in later years. I bet they are lift- & drag-reducing.



So if I had one of these cars, I'd swap for the lip spoiler. (Well, if I had one of these, I'd do an A-B-A comparison of both types first ... no, then I'd probably abandon spoilers altogether for a kammback or boat tail)

Maybe you can find someone on a PT forum willing to do a swap.