wind drag/weight conversion
I hope this doesn't stir anything up. I heard an interesting comparison idea from a friend the other day. He said with a truck pulling a trailer. For every foot the trailer extends above the roof l...
Forum Discussion
A person that delivers rv trailers has posted numerous times, the WORST mpg trailer is a ball mount with corrugated aluminum sides. THe same trailer with smooth fiberglass sides weighing upwards of 700 lbs more, will net better mpgs. Not much, but better. Still worst than a front bedroom slide 5w, not as good as a non front bedroom slide 5w, nor as good as an airstream! ANY trailer with the aluminum siding is worst than its heavier counterpart with smooth fiberglass walls.
Also, back in 92 when I bought my TT, on the wall of the dealer, was a poster showing what Ford's recommendations were at the time. Generally speaking max trailer with a 460 was 10K lbs "IF" the trailer had less than 80 sq ft of frontal area. from 81-100, you were to lose 2500 lbs, or max trailer of 7500, 101-120 was reduced another 2500 lbs to 5000 max. And it was not recommended you tow a trailer etc over 120 sq ft.
While a lot of folks will not keep frontal area, or its ease of going thru the air as a factor in towing performance, it should be a factor just as weight is. Tow ratings are generally speaking, performance ratings, ie will it pull the load up a 12% grade as in the J2087 specs in first gear. WIll it hold at least 35mph on a 5% grade in 100F temps with AC on and no overheating etc. If you are like me, and pull 20-25% grades locally frequent enough that 12% grades are a ho hum grade, I will be stalled out on some of these grades at gcwr! as the spec is not stiff/high enough for how and where I tow at. So I do use some forumulas to make sure what ever light duty truck I buy since my first stall out on a 20=% grade at 12K with a 16K gcwr 1 ton/454/th400 trans/4.10 gears. Since that time in 1991, I have yet to trust a manufacture gcwr to get me to where I need to go! My 96 6.5td with a measly 12500 gcwr, could pull 20K up a 30% grade. The 05 dmax, all of 25% at 20K! so less grade. BUT, the dmax at 20K on a 4% grade would be doing some 20 mph more than the 6.5 due to more HP. But the torque multiplication with the NV4500 was better than the allison behind the dmax. Hence why the one went up a steeper grade at slower speeds.
More than one way to look at what is a good tow rig.
marty
Also, back in 92 when I bought my TT, on the wall of the dealer, was a poster showing what Ford's recommendations were at the time. Generally speaking max trailer with a 460 was 10K lbs "IF" the trailer had less than 80 sq ft of frontal area. from 81-100, you were to lose 2500 lbs, or max trailer of 7500, 101-120 was reduced another 2500 lbs to 5000 max. And it was not recommended you tow a trailer etc over 120 sq ft.
While a lot of folks will not keep frontal area, or its ease of going thru the air as a factor in towing performance, it should be a factor just as weight is. Tow ratings are generally speaking, performance ratings, ie will it pull the load up a 12% grade as in the J2087 specs in first gear. WIll it hold at least 35mph on a 5% grade in 100F temps with AC on and no overheating etc. If you are like me, and pull 20-25% grades locally frequent enough that 12% grades are a ho hum grade, I will be stalled out on some of these grades at gcwr! as the spec is not stiff/high enough for how and where I tow at. So I do use some forumulas to make sure what ever light duty truck I buy since my first stall out on a 20=% grade at 12K with a 16K gcwr 1 ton/454/th400 trans/4.10 gears. Since that time in 1991, I have yet to trust a manufacture gcwr to get me to where I need to go! My 96 6.5td with a measly 12500 gcwr, could pull 20K up a 30% grade. The 05 dmax, all of 25% at 20K! so less grade. BUT, the dmax at 20K on a 4% grade would be doing some 20 mph more than the 6.5 due to more HP. But the torque multiplication with the NV4500 was better than the allison behind the dmax. Hence why the one went up a steeper grade at slower speeds.
More than one way to look at what is a good tow rig.
marty
