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Discussion Starter #1
Between Fergus Falls and St. Paul i had the idea of logging who was on the road. What type of vehicle, that is. So i gave up the wheel of the pri, and had a 3rd passenger call off vehicle type as I put checks on a sheet of paper.

It was about 3-4PM and i logged just under 1000 vehicles over 3 different stretches of road. We quit when we ran out of paper, and it was just as well as we were near Minneapolis and traffic was too thick to continue.

Categories were

1. Car
2. Minivan
3. Pickup
4. SUV
5. "big truck". about 90% of these were Semis, the rest were construction trucks and motorhomes.


The results were

round------first-second-third ---- overall --- assumed highway mileage (avg)
Cars-------61--99--150----310---28
Minivan----28--30--56-----114---22
Pickup-----23--41--73-----137---16
SUV--------39--54--94-----187---18
"big truck"-34--40--59-----133---6
Total-------185-264-432---881


The "six" is based on asking some semi drivers what mileage they got. None are official estimates.

If we assume each vehicle was traveling 100 miles, we can sort of make a >very, very< informal estimate of who's burnign oil. (100 miles can't apply, probably, to the "big trucks" who probably drive 700 miles (their legal limit) per day most days)

cars = 31,000 miles = 1107 gallons
Minivans = 11,400 miles = 518 gallons
Pickups = 13,700 miles = 856 gallons
SUVs = 18,700 miles = 1039 gallons
big trucks = 13,300 miles = 2217 gallons



So, if the average big truck traveled the same distance as the average car, then 39% of the overall oil is burned by big trucks hauling stuff for business and so forth.

If the average big truck traveled twice as far as the average car, then 56% of the oil goes into big trucks.

If the average big truck traveled 3x as far, then 65% goes into those things...?


Now, clearly, the interstate in a non-urban area will have a higher concentration of big trucks hauling things than a city, and a very high % of gas is probably burned in a city, but this painfully informal experiment does seem to imply that the fuel economy of large trucks is a big cog in reducing oil use and CO2 generated on our roads.



Typical semi's are turbo-diesels, which is pretty good for highway mileage as evidenced by VW and all, but maybe they could devise some sort of Semi-Ius. :D

Considering how big of a deal fuel costs must be to truckers, maybe that is an actively pursued thing, as higher mileage with the trucks would almost have to be a HUGE competitive advantage.
 

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Discussion Starter #3
mrv said:
what, no motorcyclists out and about?
:D

there were a handful, but we didn't count them as we didn't have room on the paper and then just said fugget it. There couldn't have been 20 total, and they probably get better mileage than anything, so i think thats an acceptable compromise.
 

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Vehicle Survey

I think your estimates on semi's are probably off. I have some in-laws that are long haul truckers, and they average 200,000 miles per year combined, as team drivers in one tractor. And, their fuel consumption is around 4.5 to 5.0 mpg, depending on the load and type of country they are driving in.

They buy a new tractor about every 2.5 years just before the 500,000 mile warranty runs out.
 

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I bet semi drivers would greatly appreciate a synergy drive system if it could be practically developed for the truck. They have to go through so many gear shifts to get to speed.
 

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Discussion Starter #6
Re: Vehicle Survey

Phoenix said:
I think your estimates on semi's are probably off. I have some in-laws that are long haul truckers, and they average 200,000 miles per year combined, as team drivers in one tractor. And, their fuel consumption is around 4.5 to 5.0 mpg, depending on the load and type of country they are driving in.

They buy a new tractor about every 2.5 years just before the 500,000 mile warranty runs out.

500,000 mile warranty would make me all warm and fuzzy inside... but not if i had to drive 200,000 miles a yaer. :?:

So you offer that 5 would be a better estimate of mileage, which would only increase the percent of oil used by trucks, i guess. They must use an overwhelming percentage of diesel fuel. Not that they can stop, trucking is a completely necessary part of the economy. Maybe if fuel costs keep going a new element of shipping will spring up to organize LTL and TL shipments on trains. Maybe trains aren't more economical than trucks... i don't know too much about the shipping industry.
 

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Discussion Starter #7
DanMan32 said:
I bet semi drivers would greatly appreciate a synergy drive system if it could be practically developed for the truck. They have to go through so many gear shifts to get to speed.
i agree. if i was a semi-manufacturer, i'd be 24/7 on the fuel economy issue and, if i successfully got say 7 instead of 5, i'd be talking about it everywhere.

200,000 miles per Phoenix's post at 5mpg = 40,000 gallons of fuel = $125 (and growing) dollars. At 7MPG that would be only 28,500 gallons or ~$90k. $35k/year for 2mpg??? I'd take that. :lol: :lol:
 

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Semi Fuel Consumption

I don't know if there is much they can do about improving mpg. Semi's aren't very aerodynamic, and rolling resistance is pretty high when the entire rig weights about 70,000 pounds. Maybe solid steel tires (as in train wheels)?

We see a lot of trailers on trains going through Phoenix, so I think that is an alternative that is already being exploited. But, trains don't always go where you want to, like buses and airplanes.
 

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Re: Semi Fuel Consumption

Phoenix said:
I don't know if there is much they can do about improving mpg. Semi's aren't very aerodynamic ....
I remember seeing a news thing about this many years ago. There are ways to improve the aerodynamics of the tractor trailers, but often it isn't seen as a costworthy action or too much work... Such things as putting an upward sloping metal ramp-like thing above the cab of the truck to the height of the top of the box trailer is the main one I see out there on trucks. Other ideas I saw on that news show I haven't seen as often, which are similar ramp-like things connecting all around the cab of the truck over the gaps leading to the box trailer, and also some tapering shrouds at the back of the box trailer (almost a torpedo looking end rather than a big square end) to help with the trailing airflow...
 

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Even if synergy drive didn't improve FE, which I am sure it would, it could reduce driving fatigue since there is no shifting involved.

Trains may not go directly to the destination or located at the source, but would work for long haul runs, then have regional/local trucking pick up the slack, just like highways don't go exactly where you want to go, but smaller roads fill in the gaps.
I brought this concept up to someone, and they reminded me that cargo planes are often used for long hauls. I don't know which is more economical when considering both energy and time: train, plane or truck.
 

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Discussion Starter #11
A quick summary of hybrids -vs- "same car' non-hybrids

city/highway/curb weight/drag

Camry 4 cylinder: 24/33/3373/.28
Camry hybrid: 40/38/3680/.27

So, the hybrid is a bit heavier. Which matters to a car, but even 5000 pounds of batteries in a Semi are probably a moot point (except for the fact that they'd eat into cargo capacity, i guess, which is maybe a very big deal)

Highlander: 19/35/3604/0.34
Highlander hybrid: 33/28/4070/0.34


Civic: 30/38/2740
Civic with Auto: 30/40/2804
Civic Hybrid: 49/51/2869

Accord:
Accord hybrid:

Vue: 22/27
Vue hybrid: 27/32



OK, im' out of time. I have alot of reading to do on how these different hybrid systems work. But it seems at least somewhat reasonable that a mileage improvement (for highway, as i suspect only highway is rleevant to Semis) could be had w/le batteries.

I bet somebody is working on this as we type.
 

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There is a resurgence now in short-haul shipping via waterway and using smaller intermediary trucks (like those D-C Sprinters ) to deliver vice all double-rigged semis...

That would work well on the coasts and new rivers, at least
 

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Hummius said:
Between Fergus Falls and St. Paul i had the idea of logging who was on the road. What type of vehicle, that is. So i gave up the wheel of the pri, and had a 3rd passenger call off vehicle type as I put checks on a sheet of paper.

.
You didn't give Prius its own count? You might have counted me, as you went right through my neighborhood.
 

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Discussion Starter #15
Hep said:
Hummius said:
Between Fergus Falls and St. Paul i had the idea of logging who was on the road. What type of vehicle, that is. So i gave up the wheel of the pri, and had a 3rd passenger call off vehicle type as I put checks on a sheet of paper.

.
You didn't give Prius its own count? You might have counted me, as you went right through my neighborhood.
i didn't count pri, but there were 3 or 4.

I am often on that road between fargo and st paul, going one direction or the other.
 
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