2011 Prius to get full boat tail w/ faired trailer - Fuel Economy, Hypermiling, EcoModding News and Forum

aerohead · 03-31-2011, 06:58 PM

(Admin note: this thread originally started in http://ecomodder.com/forum/showthrea...-t-7839-3.html )

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An old college chum drove down from Colorado Springs in his new Prius for a day visit and 23-mile off-road bike ride below Lake Ray Roberts.Then a bunch of Tex-Mex to destroy any health benefits of our ride!
He liked the trailer concept and is going to do one for his Prius.
Harbor Freight Tools sells the same trailer I have at the same price I paid in 1986!
My friend will use the next step up the food chain,with larger wheels and radial trailer tires.
He has a THULE receiver-hitch bike rack already which will make for sturdy,safe towing.
We have the same engineering degree and perhaps he'll have some different and creative 'solutions' to the gap-fillers.
It'll be fun! Maybe low 60s mpg in straight interstate highway motoring.

MetroMPG · 03-31-2011, 07:01 PM

Hi Phil -

That sounds like fun. Any chance you can encourage him to document his project here?

With the Prius already being a bit of a poster child for contemporary aero efficiency, I can guarantee that tweaking one with an aero trailer would attract a lot of eyeballs & show people that even the "good" contemporary designs have potential for improvement.

Darin

aerohead · 03-31-2011, 07:19 PM

Quote:

Originally Posted by MetroMPG

Hi Phil -

That sounds like fun. Any chance you can encourage him to document his project here?

With the Prius already being a bit of a poster child for contemporary aero efficiency, I can guarantee that tweaking one with an aero trailer would attract a lot of eyeballs & show people that even the "good" contemporary designs have potential for improvement.

Darin

Darin,I've had him check out EcoModder.com so he's acquainted.
The nature of his endeavor may have to remain shrouded in a bit of mystery as it may entail more than one trailer ( if you get my drift).
But I'll ask.It would be good, and we could all commiserate together!
Cd 0.25-to- Cd 0.125 has an alluring aroma.

Varn · 04-04-2011, 12:12 AM

I would want to run the same wheels on both car and trailer. Depending on the aerodynamics adding two more wheels might add more drag than the trailer solves, particularly if the vehicle has good aero to start with.

He might try using zote foam as a connection of his panels. This was implemented by an artist friend of mine. I have used it on recumbent bicycles and it may work well as a trailing edge of a motor vehicle. It could be attached to the car and overlapped to the trailer. I doubt if an overlap is of much importance when going from larger to smaller.

aerohead · 04-11-2011, 02:48 PM

Quote:

Originally Posted by Varn

I would want to run the same wheels on both car and trailer. Depending on the aerodynamics adding two more wheels might add more drag than the trailer solves, particularly if the vehicle has good aero to start with.

He might try using zote foam as a connection of his panels. This was implemented by an artist friend of mine. I have used it on recumbent bicycles and it may work well as a trailing edge of a motor vehicle. It could be attached to the car and overlapped to the trailer. I doubt if an overlap is of much importance when going from larger to smaller.

I'm pretty confident that we can overshadow the extra R-R of the tires/wheel-bearings with the Cd reduction.
When I pulled the original 2-wheel trailer to California empty,and back loaded with a 1/4-ton of batteries along with all my other gear,I only took a 2-mpg penalty with the CRX,dropping from 52,to 50 mpg running 1,000 lbs over curb weight.That was without any gap-fillers between car and trailer,no 'underside',and zero wheel fairings.
I don't know yet if I can 'add' mpg,but I think it would be easy to net out at zero loss.
The T-100 should be less sensitive to a weight addition than the CRX and the Prius trailer could be constructed at no more than 200-lbs total weight.
Appreciate the Zote foam info,I'm sure my friend will be looking at all the posts and can value from the data.Thanks!

aerohead · 04-16-2011, 05:00 PM

Just checked my email.My friend Gary says sharing the Prius trailer build on EcoModder.com is okay and he'll want to lean on as many of us as necessary.
Gary is going to do a 'shorty',only long enough to complete the 'Template' boat-tail without any consideration for carrying capacity.
He does regular I-25 runs between Colorado Springs and Denver and is indicating around 54 mpg with the naked car.So that will be the figure to beat.
I've been working 7-day weeks since November and have some savings built up to finance my return to the Viking project for World of Speed in Sept..