What does 11,000 lbs of towing capacity mean?

Taco wrote:
I would guess that the trucks no longer have a frontal area deduction because power is no longer a limiting factor in towing performance. In 92 a 454 or 460 probably made 230 horse a diesel made probably 180 or so. Now a base v6 makes 300 horse and a respectable towing engine is 350 to 400+. The limiting factor now has more to do with payload, stopping power, and stability than horsepower.

BUT< the new specs include a max frontal area of 60 or 80 sq ft to get the tow ratings. SO, with this in mind, if you are over this amount, one needs a deduct in the ratings no matter how little you think it may be. 3 sq ft of frontal area wind resistance is equal to the same HP as if adding an additional 1000 lbs of wt to a rig. No matter how much HP you have today vs yesterdays trucks, this same deduct is needed off of the total max trailer one can pull to keep the same performance.

I noticed this one time when I pulled a small trackhoe from Seattle to Ellensburg and back. I got 1-2 mpg more with the trackhoe at about 70Sq ft of frontal area and 15K lbs vs my TT at 15K and 90sq ft. I was able to pull the hills one gear taller and 5-7 mph faster. Yeah it was a 185/385TD, but none the less, I was faster. I noticed some of the same difference with my dmax between trailers also. If Fleets of Class 8 trucks are doing things with aerodynamics to get better mpg etc to there fleets, it effects us also. ALtho their savings are in the hundreds if not millions of dollars a year if they can get a .1-.3 mpg saving.

Marty

Marty