Trailer Mod Drawing to Scale

[aerohead]

We're building up a comprehensive database for the EcoBoost F-150.It's great!
By the time you're back from Florida we'll know a great deal about EcoBoost-RV travel trailer aero/mpg.

[aerostealth]

I posted a new blog at evworld.com today. You can find it under my name John Gilkison in the commentary section. The title is TrailerTopia.

[aerohead]

I used some rolling resistance values from CATERPILLAR's online 'UNDERSTANDING TRACTOR-TRAILER PERFORMANCE' and estimated a BSFC of 0.537 for the naked F-150.
Using this BSFC,I used the towing mpgs to reverse-engineer the road loads necessary to explain the difference.
I came up with 3.72-hp rolling resistance penalty for the loaded trailer, and 14.364-hp additional aero losses.
Using the frontal area of the pickup as a reference,the aerodynamic loading of the trailer/Kubota tractor combination creates a tax on the F-150 equivalent to raising it's drag to Cd 0.691,up from Cd 0.34 for the solo Aerolid combo.
From Caterpillar,the rolling force coefficient for the set of 4-tires,and any powertrain friction,at 55-mph is 0.00802205,based on the all-up weight of the truck.
I used the same coefficient to estimate the trailer R-R load.
If any members want to run the numbers as well,Based upon AeroStealth's values,it would be good to have a second set of eyes on this.
I feel like quite the neophyte when it comes to trailers.
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PS @ Cd 0.691 and 36-sq-ft we get CdA 24.876 sq-ft.
If we consider APEX's 62-sq-ft frontal area as the reference for the 'rig',then to get 14.5 mpg towing APEX at 55-mph,the Cd of the F-150/trailer combo would need to be no greater than Cd 0.401? (A little better than a NASCAR 2-car draft)

[aerostealth]

Some back of the envelope calculations tells me we could be looking at between 15 mpg and 16 mpg and a Cd of .39 down from .601. I used 13.6 mpg as a baseline for the truck and trailer with the modified Aerolid. I should have a baseline for a empty bed towing the trailer tomorrow. I would just love to see 15 mpg period.

[aerostealth]

My naked bed towing test this morning point to 10 mpg at 62 mph for Apex behind the Ford XLT. The result average of 11.6 mpg for my tow rig with the aerolid flared out looks to be a 13.8% improvement already. Additional mods to the trailer itself look to be low hanging fruit.