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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 12-20-2017, 05:30 PM   #1 (permalink)
Corporate imperialist
 
oil pan 4's Avatar
 
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 11,175

Sub - '84 Chevy Diesel Suburban C10
SUV
90 day: 19.5 mpg (US)

camaro - '85 Chevy Camaro Z28

Riot - '03 Kia Rio POS
Team Hyundai
90 day: 30.21 mpg (US)

Bug - '01 VW Beetle GLSturbo
90 day: 26.43 mpg (US)

Sub2500 - '86 GMC Suburban C2500
90 day: 11.95 mpg (US)

Snow flake - '11 Nissan Leaf SL
SUV
90 day: 141.63 mpg (US)
Thanks: 269
Thanked 3,522 Times in 2,796 Posts
Roof rack better or worse than a small trailer?



For fuel economy. What do you think?

Attached Thumbnails
Click image for larger version

Name:	20171220_152638.jpg
Views:	662
Size:	23.3 KB
ID:	23206  
__________________
1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, corvette gen 5 front brakes, 1LE drive shaft, 4th Gen disc brake fbody rear end.
2011 leaf SL, white, portable 240v CHAdeMO, trailer hitch, new batt as of 2014.

Last edited by oil pan 4; 12-20-2017 at 07:22 PM..
  Reply With Quote
The Following User Says Thank You to oil pan 4 For This Useful Post:
aerohead (12-23-2017)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 12-20-2017, 06:01 PM   #2 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 27,561
Thanks: 7,736
Thanked 8,554 Times in 7,041 Posts
I think I can't see it.

Why not both?

__________________
.
.
Without freedom of speech we wouldn't know who all the idiots are. -- anonymous poster

____________________
  Reply With Quote
The Following 2 Users Say Thank You to freebeard For This Useful Post:
Daschicken (12-21-2017), Xist (12-20-2017)
Old 12-20-2017, 07:32 PM   #3 (permalink)
Master EcoModder
 
oldtamiyaphile's Avatar
 
Join Date: May 2009
Location: Australia
Posts: 1,510

UFI - '12 Fiat 500 Twinair
Team Turbocharged!
90 day: 40.3 mpg (US)

Jeep - '05 Jeep Wrangler Renegade
90 day: 18.09 mpg (US)

R32 - '89 Nissan Skyline

STiG - '16 Renault Trafic 140dCi Energy
90 day: 30.12 mpg (US)

Prius - '05 Toyota Prius
Team Toyota
90 day: 50.25 mpg (US)

Premodded - '49 Ford Freighter
90 day: 13.48 mpg (US)

F-117 - '10 Proton Arena GLSi
Pickups
Mitsubishi
90 day: 37.82 mpg (US)

Ralica - '85 Toyota Celica ST
90 day: 25.23 mpg (US)

Sx4 - '07 Suzuki Sx4
90 day: 32.21 mpg (US)

F-117 (2) - '03 Citroen Xsara VTS
90 day: 30.06 mpg (US)
Thanks: 325
Thanked 452 Times in 319 Posts
Trailer, I've had a few record trips towing various trailers.

I think especially with a Prius where the roof shape is critical to drag, you'll see a big hit if anything is ruining airflow attachment.

On a big boxy vehicle it wouldn't matter as much, but again the boxier shapes mean the trailer follows in the vehicle's wake.

We know that it's at least possible to make a trailer that improves economy- I've never seen that with any roof mounted accessory.

Plus, I never feel 100% safe with a load on the roof.
__________________







Last edited by oldtamiyaphile; 12-20-2017 at 07:39 PM..
  Reply With Quote
Old 12-20-2017, 08:38 PM   #4 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 27,561
Thanks: 7,736
Thanked 8,554 Times in 7,041 Posts
Quote:
We know that it's at least possible to make a trailer that improves economy- I've never seen that with any roof mounted accessory.
Lest we forget:

http://ecomodder.com/forum/showthrea...ted-26915.html

In 2013 HHOTDI moved his CVT from the rooftop to a hitch mount, and confounding all expectation excepting mine, he gained mpg over a slick top.

Quote:
I just returned home from a 770 mile round trip to Portland, lake Oswego and home! I returned home late last night and checked the hard mileage and found 770 miles, 15.6 gallons netted 49.3MPG! So as Freebeard suggested, what will we do if the mileage goes up?!?
Beetle w/o any attachments/slick top= ave 48mpg :{)
Beetle with factory VW Roof racks and CVT tent= 38mpg :/
Beetle with new areo-hitch mounted rack/CVT tent= 49.3MPG WhoooRah!
That is a gain of 11.3 mpg boys and girls!
__________________
.
.
Without freedom of speech we wouldn't know who all the idiots are. -- anonymous poster

____________________
  Reply With Quote
Old 12-20-2017, 08:57 PM   #5 (permalink)
Master EcoModder
 
oldtamiyaphile's Avatar
 
Join Date: May 2009
Location: Australia
Posts: 1,510

UFI - '12 Fiat 500 Twinair
Team Turbocharged!
90 day: 40.3 mpg (US)

Jeep - '05 Jeep Wrangler Renegade
90 day: 18.09 mpg (US)

R32 - '89 Nissan Skyline

STiG - '16 Renault Trafic 140dCi Energy
90 day: 30.12 mpg (US)

Prius - '05 Toyota Prius
Team Toyota
90 day: 50.25 mpg (US)

Premodded - '49 Ford Freighter
90 day: 13.48 mpg (US)

F-117 - '10 Proton Arena GLSi
Pickups
Mitsubishi
90 day: 37.82 mpg (US)

Ralica - '85 Toyota Celica ST
90 day: 25.23 mpg (US)

Sx4 - '07 Suzuki Sx4
90 day: 32.21 mpg (US)

F-117 (2) - '03 Citroen Xsara VTS
90 day: 30.06 mpg (US)
Thanks: 325
Thanked 452 Times in 319 Posts
Mounting an accessory to fill the wake of one of the least aero economy cars in decades doesn't count. Besides, hitch mounting makes it a trailer

It's more akin to how when I load an open vehicle I try to distribute the load so it forms a kamm back.
__________________






  Reply With Quote
Old 12-20-2017, 09:04 PM   #6 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 27,561
Thanks: 7,736
Thanked 8,554 Times in 7,041 Posts
Doesn't count?



I agree the New Beetle shares the old Beetles biggest problem. The old Beetle used the inward falling vortexes to gain engine cooling.
__________________
.
.
Without freedom of speech we wouldn't know who all the idiots are. -- anonymous poster

____________________
  Reply With Quote
Old 12-20-2017, 10:53 PM   #7 (permalink)
It's all about Diesel
 
cRiPpLe_rOoStEr's Avatar
 
Join Date: Oct 2012
Location: Porto Alegre, Rio Grande do Sul, Brazil
Posts: 12,548
Thanks: 0
Thanked 1,622 Times in 1,447 Posts
While going through a toll road where the additional axle(s) in a trailer would mean a higher cost, I'd try a roof rack with an air deflector (similar to the ones fitted on the rooftop of certain trucks with a box van body) in front of it to smooth out the air flow.
  Reply With Quote
Old 12-20-2017, 11:45 PM   #8 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 27,561
Thanks: 7,736
Thanked 8,554 Times in 7,041 Posts
Quote:
Besides, hitch mounting makes it a trailer
Here's a single-wheel trailer that folds and folds up against the tailgate of a pickup truck:



Plus a half-tonneau and Coanda nozzles on the twin stacks.
__________________
.
.
Without freedom of speech we wouldn't know who all the idiots are. -- anonymous poster

____________________
  Reply With Quote
The Following 2 Users Say Thank You to freebeard For This Useful Post:
aerohead (01-13-2018), Xist (12-21-2017)
Old 12-21-2017, 07:49 AM   #9 (permalink)
Rat Racer
 
Fat Charlie's Avatar
 
Join Date: May 2011
Location: Route 16
Posts: 4,150

Al the Third, year four - '13 Honda Fit Base
Team Honda
90 day: 42.9 mpg (US)
Thanks: 1,784
Thanked 1,922 Times in 1,246 Posts
It depends on the load.
__________________

Quote:
Originally Posted by sheepdog44 View Post
Transmission type Efficiency
Manual neutral engine off.100% @MPG <----- Fun Fact.
Manual 1:1 gear ratio .......98%
CVT belt ............................88%
Automatic .........................86%

  Reply With Quote
Old 12-22-2017, 10:47 PM   #10 (permalink)
It's all about Diesel
 
cRiPpLe_rOoStEr's Avatar
 
Join Date: Oct 2012
Location: Porto Alegre, Rio Grande do Sul, Brazil
Posts: 12,548
Thanks: 0
Thanked 1,622 Times in 1,447 Posts
Quote:
Originally Posted by Fat Charlie View Post
It depends on the load.
It's also worth to remind that certain loads which could be safely moved with a trailer might exceed the payload rating when a roof rack is used instead.

  Reply With Quote
Reply  Post New Thread


Tags
roof rack, trailer

Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com