I had a few people who criticized how my truck looks by comparing it to a Pontiac Aztec. We were at Sam's Club and I happened to park beside one so I took a picture for your edification. There is no way the air can follow the rear end roof slope of the Aztec but it can on my truck. I find it strange that some people are so hung up on looks enough to totally discount performance.
My brothers son is working on putting a 1966 Chevy truck back on the road. They have dropped a 327 Cubic Inch V-8 engine in it and changed the transmission to a 3 speed auto with overdrive. While I applaud the gear changes I just had to ask my brother just how much HP could that engine put out?
He told me 350 HP. I explained to him I had a 213 Cubic Inch V-6 that could put out 365 HP and it was mated to a 6 speed auto. What Rob may not understand about his new wonder truck is that it has a Cd of around 0.5.
On my truck doing 80 mph it takes about 30 HP to overcome rolling resistance and 48 HP total to do 80 mph. The remaining 48-30 = 18 HP is overcoming drag. MY truck naked (Cd=0.402) needs 64 HP to do 80 MPH so it is then requiring 34 HP to overcome drag. In other words my Herndon Aeroshell which reduces the Cd to 0.34 has reduced my HP requirements to do 80 mph to overcome aerodynamic drag by about 48%.
We will have some warm weather data for you all in April when I meet Phil at Monahans SP. I do find it interesting how completely unaware people really are about the real forces that are affecting the mileage in their vehicles.