3rd gen Prius aeromod thread

[MetroMPG]

Originally Posted by redpoint5

I don't believe it will improve MPG since the underbody was already engineered to be aerodynamically efficient, but I look forward to the test results.

I dunno, I think there's still room for improvement or a dam up front. It's pretty far from smooth underneath.

[Vman455]

Well, the air dam doesn't appear to be hurting anything. I had to go to Springfield today, ~80 miles on I-72, cruise at 55 both directions, set-it-and-forget-it, temperatures in the 50s. The way over:



And back:



Interestingly enough, comparing with this chart from Wayne Gerdes:



...my average today, 66 mpg, was 6.28% better. Figuring 2% drag reduction:1% fuel economy improvement, that suggests a drag coefficient 12.56% lower than stock, or .2186--not including any temperature compensation.

[Xist]

Weekday mornings? How civilized!

I knew that evenings on weekends would be busy. A girl that I started dating told me that she was driving Uber until she paid off her medical bills. She referred to that a few times as "picking up drunks."

It has been a couple of weeks and I have hardly heard from her.

I will live.

Someone that I know was bragging about getting 46 MPG in her Prius. The average user-reported mileage in a 2005 is 46.75, according to the EPA.

I average forty-six and users have asked what I am doing wrong, why is it so low.

How does the Prius MPG display compare with the pump? I believe that people have said OEM displays are generally 1-5% high.

[Vman455]

Originally Posted by Xist

How does the Prius MPG display compare with the pump? I believe that people have said OEM displays are generally 1-5% high.

I've kept track of that in my fuel log, recording what the factory display says as well as the Scangauge. Factory is always high by a couple mpg; Scangauge is almost always low.

[Xist]

Originally Posted by Vman455

Scangauge is almost always low.

Does it defy calibration?

[Vman455]

It's got me stumped. It's usually off one way or the other by .2 gallons when I fill up (tonight, I put in 9.672 gallons, and it estimated 9.5), but there doesn't seem to be any rhyme or reason to it. It seems to have reached the limits of its accuracy with the hybrid system; one reason for the constant error may be the blanket .02 GPH estimation when running in EV mode.

[Vman455]

Another 15 pounds off the car tonight and over the past few weeks:

• Rear hatch upper trim: 3.2 lbs
• Intake resonator: 2.0 lbs
• Rear seat headrests: 2.8 lbs
• Rear floor panels: 3.8 lbs
• Trunk cover: 4.2 lbs

I've decided on two winter projects, as well. First, rear wheel skirts. And second, I'm going to try a base plate (Task 12.3 here). I'll use a Torklift Ecohitch, which should have the least drag penalty of any hitches available for the Prius as most of it is hidden under the plastic diffuser panel rather than hanging below it, then steel box section out the back and an appropriately-sized base plate with cutout at the end (the lowest-drag configuration found by the MIRA researchers, at 6.4% reduction). The idea is, I'll be able to pop this on the back for long road trips, like the two I have planned next year, but when I've reached my destination I can take it off and it should be small enough to store in the hatch so I can drive around downtown Houston or Seattle without being inadvertently rammed.

[aerohead]

Originally Posted by Vman455

Another 15 pounds off the car tonight and over the past few weeks:

• Rear hatch upper trim: 3.2 lbs
• Intake resonator: 2.0 lbs
• Rear seat headrests: 2.8 lbs
• Rear floor panels: 3.8 lbs
• Trunk cover: 4.2 lbs

I've decided on two winter projects, as well. First, rear wheel skirts. And second, I'm going to try a base plate (Task 12.3 here). I'll use a Torklift Ecohitch, which should have the least drag penalty of any hitches available for the Prius as most of it is hidden under the plastic diffuser panel rather than hanging below it, then steel box section out the back and an appropriately-sized base plate with cutout at the end (the lowest-drag configuration found by the MIRA researchers, at 6.4% reduction). The idea is, I'll be able to pop this on the back for long road trips, like the two I have planned next year, but when I've reached my destination I can take it off and it should be small enough to store in the hatch so I can drive around downtown Houston or Seattle without being inadvertently rammed.

I'd be reluctant to mess with the intake tract,as it is 'tuned',just like the exhaust system.And it could alter the efficiency of the exhaust system as well.
Toyota is a master engine designer.They wouldn't create components arbitrarily.

[Vman455]

I took advantage of the last warm-ish day for a while to straighten out my airdam. I attached it originally with the bumper cover off the car, so it was significantly lower at the sides, just in front of the wheels, than in front, and was scraping on the sides a lot. I lowered the front an inch and raised the sides, for 3 1/2" clearance all around.







I found 40' of lawn edging on clearance at Walmart for $7.00 just before Christmas, so I figure I'll put some side skirts on it as well. Then rear wheel skirts, then a base plate.

[igo]

Have to say I am impressed so far! Things are looking good and you are pulling some good numbers! Keep it up