Quote:
Originally Posted by NeilBlanchard
A little weight makes a very small difference, and aero matters at slower speeds than you think. A truck has higher drag than an average car, and average cars hit 50% of the load from aero drag at <30MPH.
Pretty much everybody drive at least 30MPH much of the time - so aero matters to everybody, much of the time.
|
Aero matters to steady state driving. Hardly at all to stop and go in most metro areas. Point taken, but route efficiency, engine idle time and vehicle mechanical condition trump aero in nearly all ways. For most purposes, and for most persons.
Certainly, though, aero "help" is needed more with a pickup. Right to the point it begins interfering with ability to do work. When it becomes counterproductive.
I was passed this afternoon by a cherry late 1990s Dodge one ton, standard cab with a HD steel contractor pack (tailgate removed, HD doors; exterior access doors on sides) and a low profile roof rack. Again, HD. All painted body color. Premium tires on stock wheels. Nothing out of line. Far from what I'd see forty or fifty years ago that contractors would make for themselves. This was close and compact in engineering. "Aero", by any definition. Government or utility contractor quality. The best.
That mans' main gains would be from replacing body bushings, steering shaft and the rest of the front end to eliminate the steering slop I know it has. That truck is old. Rubber rots. Pickups need perfect steering more than aero (in about 90% of cases. It's the noise in the numbers nearly every time).
That, and route optimization plus engine idle discipline is about all that's needed otherwise.
The "beauty" of aero is when all else is like new. And use scrutinized like a businessman. (No more runs to the convenience store at ten pm). Only then.
Without such a background -- or use confined to highways -- aero is too slippery for non steady state, low speed driving to determine results. I'm not going to argue Zenos Paradox, but if we on the one hand want to see some ABA testing, then elimination of variables still come first.
I love the work, no question. Want something for mine. And this thread shows a beauty. I'd like to meet the owner, to shake his hand and sincerely compliment his work in person (which is how I read the "below sixty mph advantage; as part of a compliment). The thread is lovely inspiration. Would be a boon to society far more than beards, tattoos and tee shirts to see dozens of such bed covers in a day.
But I could take an otherwise identical truck and install the above contractor pack with full size ladder rack and produce better mileage than with an aerolid. If "use" isn't quantified by any owner of any project (ability to do work part of that), then aero below 60-mph is fairly without meaning. Let me set the definitions of "work" (there is no other reason for a pickup) and my engineered "aero" contractor package will kick ass over an ordinary pickup with an aerolid.
It won't take much to win.
At the end of the calendar year this aerolid "should" show a percentage improvement to the annual average mpg. Assuming records exist. And no other changes are made. No repairs. No change to tire design. Not to routing. Not to driving style. Not to idle discipline. Not to work performed, etc. (Not likely, in other words).
The effect of aero improvement won't be separated (recognizable) at low, non steady state speeds. I can easily believe improvements to crosswind handling, etc. "Seems easier to drive". ("Feelingz")
Quantifying it is something else.
.