Road Horse Power

[aerostealth]

It is what you think you know that ain't so that can be the biggest obstacle to knowledge. I for one have no problems with traveling on the interstate highways at the posted speeds all day long. The truck is very stable at highway speeds, the fuel economy is good with aero and the engine is just loafing. In fact I would maintain that higher speeds put the engine in a more efficient place meaning a little more load.

[slowmover]

I understand you believe you have a point to make. And that skill somehow compensates. I agree that better aero helps. But doesn't overcome the deficiencies of a pickup truck. Cars will skid and spin around well above the point where trucks roll over. Which is why the DPS Tahoes are lowered so dramatically. And why the operators have to exert such care at high speeds. (Their words to me). Keeping risk to a minimum is the only avenue worth exploring, long term. All other approaches have a higher cost. Driving skill arguments are a dead end.

Pickup trucks are about payload. It is their reason for being. Towing an especially large load compared to a car is second. They are a failure for passenger transport unless we include vans as to seat mpg.

Questions about payload, axle and tire loads, etc may not be exactly to your vision, but they are nevertheless central to what is a pickup truck. On that, with your truck and with or without your trailer, are the trade offs understood by others to arrive at a more satisfactory average annual mpg. It isn't merely highway versus city (better said as steady state versus stop and go), but working versus empty. How well is it justified if only for fuel expense (becomes the question)?

Empty miles don't pay. The cheaper they are, the better, granted. Things tend to come down to the percent of each. One can read the experiments of others with this known. As with climate and terrain past truck spec. Comparisons. Your mpg appears to be just above mine at 55 and at 65. Today's turbodiesel 1T trucks are grossly overpowered with a stratospheric initial cost and no longer desirable from a mpg standpoint versus work performed. But my comparison is made to yours when my truck is solo and loaded to 87% of gross.

So, how to compare? Would a replacement gasser 1/2T truck with aero aids skew the empty miles high enough for me to warrant the change? Etc. My travel trailer is heavy, but aero. A half ton can do it. But how well becomes the salient point when all miles are considered. A grey area.

I'm not alone in approaching pickups from the standpoint of commercial considerations. It separates the wheat from the chaff. And it isn't meant to be a wet blanket. On the contrary, it -- your truck, solo and towing -- can be powerful evidence of how to make a particular kind of pickup truck work more favorably. Shining a light on the grey areas is what is being asked.

Weights, loads, and steady state mpg as you accumulate miles will be greatly appreciated. And skillful use of a certified Cat Scale is your friend as to reducing road horsepower as you iron things out.

Thanks for your consideration.

[freebeard]

Just a car guy : Not enough Dodge; too much Ram

[aerostealth]

My truck with full aero kit and me in it plus about 100 lbs of travel gear weighed 6,360 lbs. The front axle weighed 3,420 lbs. This means 53% of the weight was on the front axle and 47% of the weight was on the rear axle. This hardly qualifies as overly light in the rear or front heavy. A lot of cars do not do this good.

[aerostealth]

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.

[slowmover]

Ah, lovely Monahans. If an all too large white 579 Pete with all too much power and a bigh aluminum tanker blows you a kiss in passing, you can think on my 4.6-mpg average for that round trip from Corpus Christi.

Agree about the Aerolid. Tried to get a new owner of an EcoDiesel Ram interested. He already has a '69 Chevy smallblock truck for fun. And is proud of his solo and Airstream towing mpg. But, no, looks are too far out. Just think how cool a riveted aluminum bed topper with basic aero lines would look while towing that travel trailer.

[slowmover]

I

Originally Posted by aerostealth

. . . In Texas there is a stretch of turnpike where the posted limit is 85 MPH and we could easily test 90 MPH out. A 100 MPH test would be nice to start forming a good graph curve. We think the engine would be in a very efficient place at 120 MPH but my current tires and limiter would not allow me to reach that speed. P.S. At 85 MPH my RPMs were 2,050.

IH10 is better than IH20 for this. Far less traffic and better road surfaces.
There are also some bad stretches between Gillespie County and Fort Stockton as to crosswinds. I'll try and make notes of the longer, better sections per mile markers next time. The final ten miles westbound into Fort Stockton from MM 270 on a downhill, to the 259B exit for Monahans is almost absolutely flat.

Try the high octane coffee there at the Flying J.

You might also consider a CB radio. A roof mounted Larsen NMO 27 or Wilson 5000 antenna, and a Cobra 29 with bigger finals by Clays Radio Shop in San Antonio (X582, at the Petro) with a Roadking 56 mike will get you heard. A Cobra 500 DSP external speaker will aid greatly. You can also mail order something a little nicer from BELLs CB (schottky mods).

I can easily converse 10 miles or better if the other operator has a decent radio out west of JNunction. And hear farther. Which matters if knowing what Joe Law is about at that moment.

Folks have next no idea how useful is a CB. A clean, no noise install using amateur radio guidelines (and covering underside of that Aerolid with McMaster-Carr sourced copper foil, would make a great rig) and it's an altogether different beast than what us oldsters remember from the 1970s.

From Ozona west can be a pretty good concentration of LEO usually working as task forces. Not many smokey reports these days, but you'll usually get an answer as this stretch can feature drivers out at the edge of their legal hours.

[aerostealth]

Just installed this cheap wheel cover on my spare. I tried a larger cover yesterday and the air ripped it off in one mile. It is just a test as I need a more durable material then poster board.

[freebeard]

I had a few people who criticized how my truck looks by comparing it to a Pontiac Aztec.

You should swap your taillights side to side and turn them upside down. You'd probably only need to cut and swap a square foot of sheet metal to do it.