Roof rack better or worse than a small trailer?
 

http://ecomodder.com/forum/attachmen...1&d=1513808961

For fuel economy. What do you think?

I think I can't see it.

Why not both?

http://ecomodder.com/forum/member-fr...2-100-1065.jpg

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.

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.

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.

Doesn't count? :confused:

http://ecomodder.com/forum/member-fr...17-1-47-18.png

I agree the New Beetle shares the old Beetles biggest problem. The old Beetle used the inward falling vortexes to gain engine cooling.

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.
http://1.bp.blogspot.com/-_mIJohZWhO.../photo8882.jpg

Here's a single-wheel trailer that folds and folds up against the tailgate of a pickup truck:

http://ecomodder.com/forum/member-fr...ckup-truck.png

Plus a half-tonneau and Coanda nozzles on the twin stacks.

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.