What's worse for FE: a little trailer, or roof racks?

[MetroMPG]

I added to my personal flotilla on the weekend: picked up a(nother) little sailboat - a proa, kind of like this one:



It all comes apart, so I brougt it home on the roof of the Blackfly. (City driving, so the FE aero hit was small.)

The reason I got it is because it's relatively portable, and I would be able to take it to different places next summer.

So the question: I already know that my car takes a massive FE hit with anything on the roof, so what I'm wondering is whether I'd be better off getting a small trailer to pull it behind the car.

It'd be mostly in the car's wake, which is better for FE, but there's added rolling resistance, and weight.

Anyone care to speculate what would be best?

[Matt Timion]

my guess is that the trailer is better than the roof rack. THe weight won't be as much of an issue (IMHO). You can also always fab up a very aerodynamic cover for the trailer.

[MetroMPG]

I thought of the hatch mod - Xfi had a vinyl window installed in his hatch with a zipper to remove it. (Mostly for ventilation - but it would work for pass-through cargo too)

The only problem is the longest hull is 14 feet. That's almost longer than the car, and a long way to stick out! I'd be whacking pedestrians off the sidewalk when turning left

[Silveredwings]

Originally Posted by MetroMPG

The only problem is the longest hull is 14 feet. That's almost longer than the car, and a long way to stick out! I'd be whacking pedestrians off the sidewalk when turning left

...and that's ... bad, right?

[zpiloto]

I kinda remember going over this before when you did the roof rack test. The trailer would win out. You would have the benefit of the car blocking some air. You could even design the trailer as a boat tail extension. To bad you don't have a sun roof, if the wind was right you could Codfish to the lake

[kps]

I think you misunderstood what people meant by adding a boat-tail.

[MetroMPG]

KPS wins the groan prize for this thread!

[kps]

Actually, we expect nothing less than a fully enclosed tapered trailer with flexible skirts joining it smoothly to the back of the car. That, and the ability to raise the sail when the winds are favorable.

[GasSavers_TomO]

I would have to agree that the trailer would be less of a hit to FE. you could even try to find the lightest trailer that would fit your needs, aerodynamically mod it for better air flow and maybe even add some LRR tires and pack the bearings in synthetic oil instead of grease. Be sure to use LED trailer lights as well, it'll help save on battery life if you plan on trying to drive around with the alt. belt off.

hmm...I think I smell another scientific A-B-A experiment coming this way from MetroMPG!

[GasSavers_Ryland]

I'm all for the trailer idea, I'm pretty sure that you can get some nice 60psi moped tires that are speed rated at over 80mph, for how long you want to make it I would go with two wheels for stability, I talked to a guy who has a trailer for pulling behind a motorcycle that he pulls behind his TDI gulf, and I think he saw about a 4mpg decreas, but could dubble his cargo carrying capasity.