spoiler mileage test

If you look at the correlating measurements with and without spoiler, you see that the first south runs are much wider apart than the rest. If you drop those, the difference is much smaller, thus concluding that the spoiler is insignificant.

 

If the spoiler does not alter the mileage in any significant way, one must conclude that it does not alter the areodynamics in any signficant way either. Therefore, a conclution of it being insignificant in reducing any lift or enhancing proformance in any way is drawn. But it looks cool!

 

I was wondering when someone would finally reach that conclusion. Most of the "performance" enhancements sold these days are nothing more than style statements. Even the giant wings that people slap in the back of their riced out Hondas don't do much under about 80 mph, and unless they've done some wind tunnel testing, it's just as likely to provide way more drag then downforce. Race car teams spend millions in wind tunnels to tune wings that produce downforce with minimum drag, and the designs are usually carefully guarded secrets until raceday. If you somehow found a tiny spoiler that creates downforce but no drag at legal highway speeds, I'm sure IRL and Champcar would be interested in the design.

I've never thought my Prius was loose at highway speeds (which is what a rear spoiler would help, if it actually did anything). If anything, my car pushes a bit. A spoiler would just make that worse.

If I could go to the parts bin to improve handling for my Prius I would start with about 25 percent higher rate springs (not lowered since the car already bottoms on speedbumps), improved dampers, and about 50 percent stiffer anti-sway bars front and rear. (Of course none of that shows on the outside)

 

On the rear wing of many open wheel race cars there is a small vertical strip set at about 90º along the trailing edge of the wing called a “Gurney flap†(named after Dan Gurney) or “wickerbill.†It provides considerable down force at high speeds. Some Porsches have an active rear spoiler that comes up at about 75 miles an hour. Both of these devices increase down force appreciably. It is likely that the aftermarket spoiler for the Prius would raise the drag coefficient rather than lower it and it would not help at all on cross-winds. Nevertheless, it would likely generate considerable down force; it’s just a question of whether the Prius can go fast enough to for it to have an effect. I love aftermarket parts. I have a number of them on my ’91 NSX. However, it is good to keep in mind that some of them look better than they work.

I have a Silver Prius with a #7 package plus leather coming in before the end of the month. This is my first post. I Hope I wasn't out of line and too boring.

 

i appreciate your trying to be as consistant as possible, but the range of variation in your results tells me that your distance was probably too short.

also, i consider a ½ mpg to be a significant change. if this was to pan out over time, it would be well worth the mod imho. i think a real test would have to involve extensive data for a known run before and after the mod to get a long term trend.

i also suspect that the difference might be small and not overcome the deviation of the data.

 

I just got my '06 Prius and I'd like to know how is the aftermarket spoiler different to that on mine?

 

What is the real difference between the two spoliers?

does the replacement still have the 3rd brake lite installed?

 

I don't think we'll ever have a definitive answer by road-testing.. especially if 0.5mpg is the type of accuracy we're after! The only way I can see meaningful testing is in a wind tunnel.

 

The spoiler underdiscussion is the one available at the <a href=\'http://www.priuschat.com/shop/product_info.php/products_id/24\' target=\'_blank\'>BT Tech Prius Rear Aero Spoiler</a> link in the PriusChat Offers box.

I'm not so sure it applies down pressure (it's so small) as much as "spoil" the lift over the back end of the car.

 

Yep, got that one Bill - but is it any different (and how?) from my stock '06?

 

If you follow the link and look at the pictures (click for larger images) you'll see that the BT Tech spoiler attaches to the hatch glass just in front of the stock spoiler. The BT Tech spoiler is about 1.25" wide in cross section and goes from edge to edge on the glass, for a nice fitted appearance. I think it should also work with the "B" type spoiler Sigma (another sponsor) sells.

The BT Tech spoiler is used in addition to the stock spoiler, it does not replace it, like the Sigma "B" spoiler does.

 

Ok .....now I see it. Too much sun up here in Queensland....bad eyes!

Thanks Bill, I will read more and see if I can determine if it is worth adding.

 

Ahh, ok I thought this was the other Spoiler that replaces the origanal..

I didnt think the BT one would do much as it really doesnt spoil much. I mean it doesnt stick up..