Better Mileage With A Spoiler?? - Toyota Yaris Forums

MadMax · 05-18-2009, 12:59 PM

OK, as crazy as this sounds, it is a legitimate question...

Has anyone who has added a spoiler to their hatchbacks noticed any improvement in gas mileage?

I am wondering if the addition of a spoiler helps smooth the airflow in any way over the back of the car. I know the egg shape is already pretty smooth, but a spoiler could deflect the airflow in a way that makes it even more aerodynamic.

Cheers! M2

eTiMaGo · 05-18-2009, 02:36 PM

hmmm to be honest pretty much all the spoilers out there are more for cosmetics than real aerodynamic improvement... It's not all about smoothing airflow but minimizing the turbulence at the back of the car, that would require a carefully designed and tested wing...

roxy1 · 05-18-2009, 03:36 PM

spoiler on a yaris is completely cosmetic. even if it had a purpose, it wouldnt be to increase mileage, but more likely to create downforce. i added a spoiler to my 06 corolla and noticed a 2 mpg decrease immediately and consistently over a 3 month period. removed it and got my 2 mpg back. not scientific, but im certain it was just adding drag and, as a side note, looking ridiculous as spoilers usually do on economy cars.

BailOut · 05-18-2009, 03:38 PM

Quote:

Originally Posted by roxy1

spoiler on a yaris is completely cosmetic. even if it had a purpose, it wouldnt be to increase mileage, but more likely to create downforce.

Correct! And even if it did improve MPG it would be by such a small amount that the cost of it would never break even.

1stToyota · 05-18-2009, 06:21 PM

I noticed a messier rear window and I use the rear wiper more often now when it rains because the airflow seems f'd up now. Factory lip spoiler looks great though.

CtrlAltDefeat · 05-25-2009, 01:41 AM

By definition a spoiler increases drag to increase down-force. It will make your mpg worse, and slow your car down. If your car does not feel floaty and loose in the rear at high speeds, you do not need a spoiler. I always laugh my ass off at these idiots who put those giant spoilers on their shitty stock cars with nos stickers and a coffee can exhaust tip.

jambo101 · 05-25-2009, 04:25 AM

Quote:

Originally Posted by CtrlAltDefeat

. I always laugh my ass off at these idiots who put those giant spoilers on their shitty stock cars with nos stickers and a coffee can exhaust tip.

And i bet they use premium gasoline for the extra hp

CtrlAltDefeat · 05-25-2009, 04:53 AM

No, they would rather spend the money on that new sticker they've had their eye on

05-18-2009, 12:59 PM	#1
MadMax Drives: 2008 Yaris Liftback (Sprocket) Join Date: Oct 2008 Location: San Antonio, Texas! Posts: 2,799	Better Mileage With A Spoiler?? OK, as crazy as this sounds, it is a legitimate question... Has anyone who has added a spoiler to their hatchbacks noticed any improvement in gas mileage? I am wondering if the addition of a spoiler helps smooth the airflow in any way over the back of the car. I know the egg shape is already pretty smooth, but a spoiler could deflect the airflow in a way that makes it even more aerodynamic. Cheers! M2

05-18-2009, 02:36 PM	#2
eTiMaGo vroom vroom View User's Garage Drives: lil red 5-door Join Date: Sep 2006 Location: Bangkok, Thailand Posts: 7,744	hmmm to be honest pretty much all the spoilers out there are more for cosmetics than real aerodynamic improvement... It's not all about smoothing airflow but minimizing the turbulence at the back of the car, that would require a carefully designed and tested wing... __________________ The price of freedom of religion, or of speech, or of the press, is that we must put up with a good deal of rubbish. - Robert Jackson Bye bye 1NZ...

05-18-2009, 06:21 PM	#5
1stToyota Drives: 2013 Chevy Spark 1LT 5-speed Join Date: Oct 2008 Location: Oklahoma Posts: 1,185	I noticed a messier rear window and I use the rear wiper more often now when it rains because the airflow seems f'd up now. Factory lip spoiler looks great though. __________________ 1997 Lincoln Town Car - *SOLD* 2008 Scion xD (w/ automatic) - SOLD 2008 Yaris HB - SOLD

05-25-2009, 01:41 AM	#6
CtrlAltDefeat I ♥ Yaris View User's Garage Drives: Black 08 LB MT & red 97 Miata Join Date: Oct 2008 Location: Indianapolis IN Posts: 1,313	By definition a spoiler increases drag to increase down-force. It will make your mpg worse, and slow your car down. If your car does not feel floaty and loose in the rear at high speeds, you do not need a spoiler. I always laugh my ass off at these idiots who put those giant spoilers on their shitty stock cars with nos stickers and a coffee can exhaust tip. __________________ The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt. - Bertrand Russell

05-25-2009, 04:53 AM	#8
CtrlAltDefeat I ♥ Yaris View User's Garage Drives: Black 08 LB MT & red 97 Miata Join Date: Oct 2008 Location: Indianapolis IN Posts: 1,313	No, they would rather spend the money on that new sticker they've had their eye on __________________ The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt. - Bertrand Russell

05-18-2009, 03:36 PM	#3
roxy1 Drives: 2014 yaris 5 speed Join Date: Aug 2006 Location: michigan Posts: 642	spoiler on a yaris is completely cosmetic. even if it had a purpose, it wouldnt be to increase mileage, but more likely to create downforce. i added a spoiler to my 06 corolla and noticed a 2 mpg decrease immediately and consistently over a 3 month period. removed it and got my 2 mpg back. not scientific, but im certain it was just adding drag and, as a side note, looking ridiculous as spoilers usually do on economy cars.

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