Following in the footsteps of others here I have decided to build an aerodynamic cover for my 2009 GMC Sierra. The truck has a 4.8L engine, automatic transmission and 4wd. Current HWY average is 20-21 mpg US.
Highway cruising speed is consistently 105 km/h and terrain is varied on my weekly round trip that totals 550km. This is a 225km one way trip from my hometown to work.
The idea for the aerolid is following along design that Bajascoob used. I bought 100' of 1/2" tubing for $29.00 CAD and will try using some leftover 6mil vapour barrier plastic that I have.
Total costs so far:
1/2" EMT $29
1/2" EMT bender $50 (Gotta have the right tools
)
Angle indicator $22
The basic layout will be similar to Bajascoob's unless there have been any inherent faults with that design so far. A basic tapering down and in towards the tailgate will offer a rudimentary "boat tail" to the lid. I plan to have it hinge up at the front like a solid tonneau if a good strong design comes together.
So far it looks like I'll have a 12 degree slope from cab to tailgate. I'll have to hump it a little just after the cab to prevent a sharp angle change and cause airflow separation. Here are some pics of what I've started with.
