Go Back   EcoModder Forum > EcoModding > Aerodynamics
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 09-07-2019, 12:19 AM   #1 (permalink)
EcoModding Lurker
 
Join Date: Oct 2014
Location: Phoenix Arizona
Posts: 49
Thanks: 3
Thanked 2 Times in 2 Posts
2019 RAV4 Hybrid Limited

Went for my first hybrid and Iím loving it. Hypermiling the best I can and running on 91 octane fuel with tires at 48psi, I am getting 49.5 mpg average per tank as indicated on dash. I was wondering if there would be any suggestions on what to try to improve aerodynamics? I know itís higher in the air, which makes it easier to get in my driveway, would lowering it or putting an air dam help? Iím contemplating a partial grill block to help smooth out the front, but donít want to hurt the a/c function as Iím in AZ and need it bad. I have taken off the roof rack that came factory. Iíd really appreciate any and all ideas!

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 09-07-2019, 12:28 PM   #2 (permalink)
EcoModding Newb
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 6,306

Acura TSX - '06 Acura TSX
90 day: 28.39 mpg (US)

Lafawnda - '01 Honda CBR600 F4i
90 day: 47.32 mpg (US)

Big Yeller - '98 Dodge Ram 2500 base
90 day: 21.82 mpg (US)

Prius Plug-in - '12 Toyota Prius Plug-in
90 day: 57.64 mpg (US)

Mazda CX-5 - '17 Mazda CX-5 Touring
90 day: 28.88 mpg (US)
Thanks: 2,095
Thanked 2,315 Times in 1,705 Posts
I probably wouldn't mess with a grill block in AZ, and especially in a new car. You sure it doesn't have an active shutter? Many newer cars are starting to come with them.

50 MPG is crazy good. My Prius gets that.
__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
Old 09-07-2019, 12:42 PM   #3 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 10,253
Thanks: 15,519
Thanked 5,447 Times in 3,223 Posts
RAV4

clean up the belly,add rear wheel skirts,then 3-feet of boat tail.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
Old 09-07-2019, 12:49 PM   #4 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 13,522
Thanks: 3,290
Thanked 4,493 Times in 3,578 Posts
What aerohead said, plus wheel spats.

I'm curious about the the rear drive. Does it have a driveshaft or an electric rear axle?
__________________
.
Haiku are easy
But sometimes they don't make sense
Refrigerator

_________________
  Reply With Quote
Old 09-08-2019, 12:43 AM   #5 (permalink)
EcoModding Lurker
 
Join Date: Oct 2014
Location: Phoenix Arizona
Posts: 49
Thanks: 3
Thanked 2 Times in 2 Posts
I expected it to have the active shutters, but it oddly doesnít. The grill is blocked on the right and left sides a bit as in itís not hollowed out and just has the grill look to it. Was thinking of at the least doing a smooth block there just for aerodynamic effect if it would have one at all. Also with the fog light cavities, I was thinking of getting some thin plexiglass and forming it to fit and siliconing it in to smooth it out too.

Any suggestions on how to add some sort of shield over the wiper blades? Thought that might help smooth it out too.

From my understanding, it is pretty smooth on the bottom with the factory belly pan. Any advise how I could help reduce drag for it being so high off the ground? Do some sort of block in front of the tires like the eco Corollaís have? What about a short-ish airdam? Would that have the same effect as lowering it sort of?

Would taller tires help? Or smaller, low profile ones? I know I want to get the low rolling resistance ones when the factory set give out.

Thank you for the recommendations and advise. Really trying to understand and use the information.
  Reply With Quote
The Following User Says Thank You to GK13 For This Useful Post:
aerohead (09-11-2019)
Old 09-11-2019, 10:32 AM   #6 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 10,253
Thanks: 15,519
Thanked 5,447 Times in 3,223 Posts
wiper blades

Quote:
Originally Posted by GK13 View Post
I expected it to have the active shutters, but it oddly doesnít. The grill is blocked on the right and left sides a bit as in itís not hollowed out and just has the grill look to it. Was thinking of at the least doing a smooth block there just for aerodynamic effect if it would have one at all. Also with the fog light cavities, I was thinking of getting some thin plexiglass and forming it to fit and siliconing it in to smooth it out too.

Any suggestions on how to add some sort of shield over the wiper blades? Thought that might help smooth it out too.

From my understanding, it is pretty smooth on the bottom with the factory belly pan. Any advise how I could help reduce drag for it being so high off the ground? Do some sort of block in front of the tires like the eco Corollaís have? What about a short-ish airdam? Would that have the same effect as lowering it sort of?

Would taller tires help? Or smaller, low profile ones? I know I want to get the low rolling resistance ones when the factory set give out.

Thank you for the recommendations and advise. Really trying to understand and use the information.
I tested for this and found no improvement.Even adding a more streamlined windshield along with it only lowered drag 0.005.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
Old 09-15-2019, 07:08 AM   #7 (permalink)
Master EcoModder
 
Ecky's Avatar
 
Join Date: Dec 2011
Location: Vermont
Posts: 3,498

Gaptooth (retired) - '00 Honda Insight
Team Honda
Gen-1 Insights
90 day: 54.26 mpg (US)

Such Fit - '07 Honda Fit Sport
90 day: 41.27 mpg (US)

Connect - '15 Ford Transit Connect XL
90 day: 23.93 mpg (US)

K-sight - '00 Honda K-sight
90 day: 40.97 mpg (US)
Thanks: 1,286
Thanked 1,427 Times in 906 Posts
How about partial wheel arch covers? Smoother wheel covers (maybe black inserts for the gaps in the rims).

The wipers appear to already be out of the path of the air to my eye.

With Toyota's HSD, there's no benefit in terms of gearing with larger tires, since the engine has no fixed ratios with the wheels. In theory a larger diameter tire will have lower rolling resisting but is heavier and with a higher moment of inertia. A narrower tire has better aerodynamics but requires more pressure to get the same load rating. I wouldn't go significantly different from factory size.
  Reply With Quote
Old 09-16-2019, 03:02 AM   #8 (permalink)
EcoModding Lurker
 
Join Date: Oct 2014
Location: Phoenix Arizona
Posts: 49
Thanks: 3
Thanked 2 Times in 2 Posts
I would very much like to lower the wheel arch gap if I can. Been thinking of getting some ABS plastic that matches the fender flares and trying to fabricate some that would look seamless. Not too sure how to work with ABS plastic though. Thinking I can score it, bend it to match the curve, drill holes to match the existing wheel well fasteners, and go from there. Wanting to make it not stand out too much if at all.

As far as the tires go, I found out that they just have pretty standard all season tires on it. In AZ where it doesn't snow and barely rains, I'm thinking a low rolling resistance highway type tread would be the way to go. I was thinking of going with a taller, narrower tire if I could fit it on the same rim.

I saw the idea on here of sealing the panel gaps. Does that really help much? I decided to take some rubber door edge guard and put that around the gap of the hood to the front fenders/grill. Don't know if I'll see much difference though. Was thinking I could get the same stuff and wedge it in all the gaps. Use a clear or something. I'm just not sure if it would be worth doing though. Being a new car, they're pretty tight already.

With the underbody already being smoothed out with the factory belly pans, would an air dam be any benefit?

I'm also wondering how I could safely add additional battery storage to the hybrid system and add a grid charger as well. Ideally, be able to have the grid charger only charge the "extra" set of batteries so I can mitigate the risk of damaging the battery pack that came in the car. I just have no knowledge of electrical systems unfortunately.
  Reply With Quote
Old 09-16-2019, 06:09 AM   #9 (permalink)
Master EcoModder
 
Ecky's Avatar
 
Join Date: Dec 2011
Location: Vermont
Posts: 3,498

Gaptooth (retired) - '00 Honda Insight
Team Honda
Gen-1 Insights
90 day: 54.26 mpg (US)

Such Fit - '07 Honda Fit Sport
90 day: 41.27 mpg (US)

Connect - '15 Ford Transit Connect XL
90 day: 23.93 mpg (US)

K-sight - '00 Honda K-sight
90 day: 40.97 mpg (US)
Thanks: 1,286
Thanked 1,427 Times in 906 Posts
As early as the 2nd gen Prius, people have been adding secondary packs and making them into PHEVs of sorts. I'm unsure how much the 2019 differs from other model years but that kind of conversion isn't something easily done as a one-off, even with a degree in electrical engineering. Wait a few years and kits might become available.
  Reply With Quote
Old 09-16-2019, 12:12 PM   #10 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 13,522
Thanks: 3,290
Thanked 4,493 Times in 3,578 Posts
Quote:
Been thinking of getting some ABS plastic that matches the fender flares and trying to fabricate some that would look seamless. Not too sure how to work with ABS plastic though.
I did this, but in sheet metal:

If you cut a semicircular strip with the same radius as the wheelwell arch it will lay flat. If you use a straight strip and bend it it will stand out at 90į.

But if the strip is circular but with a larger radius it will form a conic sector at some arbitrary angle.

__________________
.
Haiku are easy
But sometimes they don't make sense
Refrigerator

_________________
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com