fuel economy difference in cargo shipment
fuel economy difference in cargo shipment
(OP)
Currently, I have a project that researchs methods to save fuel, mainly the practicality of using existing cars on the road to help with logistics in a region. So assuming 40000 lbs of cargo need to be shipped from point A to B (100miles). One can either use a single truck to ship this via one trip, or alternatively, one can divide up the load and ship them via cars that are planned to go from A to B (like a carpool). Since the cars are already going from A to B in the first place, the fuel required is merely the additional fuel the car will use in carrying the cargo.
I know that a 10% increase in rolling friction (dependent on weight)results in roughly a 2% increase in fuel consumption for a typical car. Assuming the car gets 27 mpg and weighs 3200lb (typical), carrying 320lbs (10% increase in weight, so roughly 10% increase in rolling friction) will result in around 2% increase in fuel burn. At 27mpg, 100 miles will burn 3.7 gallons, so 2% of that is 0.074 gallon.
0.074 gallon is the additional fuel the car used in carrying 320lb for 100 miles.
40000/320 = 125, so we multiply 0.074 by 125 = 9.25 gallons, which is the fuel that 125 cars will use in carrying the total 40k lbs.
On the other hand, a semi will get loaded to the max with 40000lb and gets around 6 mpg. 100 miles will use up 16.7 gallons of fuel.
So the first method is significantly more efficient. If the cargo has less density, the difference will be more prevalent. I merely plugged in common values to arrive at my conclusion. This is assuming the car do not have to deviate from its course to reach the drop off point.
I would like to know if there are any good literatures and sources on the situation I've just talked about because I'd like to get some good sources to back my results up. Thanks
I know that a 10% increase in rolling friction (dependent on weight)results in roughly a 2% increase in fuel consumption for a typical car. Assuming the car gets 27 mpg and weighs 3200lb (typical), carrying 320lbs (10% increase in weight, so roughly 10% increase in rolling friction) will result in around 2% increase in fuel burn. At 27mpg, 100 miles will burn 3.7 gallons, so 2% of that is 0.074 gallon.
0.074 gallon is the additional fuel the car used in carrying 320lb for 100 miles.
40000/320 = 125, so we multiply 0.074 by 125 = 9.25 gallons, which is the fuel that 125 cars will use in carrying the total 40k lbs.
On the other hand, a semi will get loaded to the max with 40000lb and gets around 6 mpg. 100 miles will use up 16.7 gallons of fuel.
So the first method is significantly more efficient. If the cargo has less density, the difference will be more prevalent. I merely plugged in common values to arrive at my conclusion. This is assuming the car do not have to deviate from its course to reach the drop off point.
I would like to know if there are any good literatures and sources on the situation I've just talked about because I'd like to get some good sources to back my results up. Thanks





RE: fuel economy difference in cargo shipment
> a single truck has a single start and possibly a single stop. If it is a single stop, then ALL of your cars need to go that same stop, regardless of whether it was really convenient or not. This adds to the cost and traffic congestion at both ends. If not, then a massive shipping and tracking system is required to plan how the product will be delivered to each of its final destinations.
> loading of cars is very manually intensive labor, compared to using forklifts to load a truck. Ditto for unloading. This adds significant amounts of labor cost.
> the more something is handled, the more likely it is sustain damage. Manual loading and unloading would statistically increase the amount of unusable product, also raising the cost.
> it's unlikely all 125 cars will all arrive and leave at the same time. This further increases the labor and holding costs, since both ends must now spend time waiting for each car to arrive to load and unload. Additional manpower and utility costs would be incurred.
TTFN
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RE: fuel economy difference in cargo shipment
RE: fuel economy difference in cargo shipment
Such a system might actually be feasible for some long haul by loading semi trailers onto trains. It would reduce fuel usage and reduce double handling and poor point to point delivery typical of train transport if a loaded trailer could simply be driven on and off from the closest rail yard to the despatch/destination points.
hht
Do your own homework. We are not a free tutoring service.
Regards
Pat
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RE: fuel economy difference in cargo shipment
Ultimately, the intent of any fuel savings project is to reduce cost. Otherwise, the solution is bicycle messengers (0 fuel usage, ideal solution.)
"Good sources to back your results up."... I'd be careful with your terminology there, these are calculations, not results. Make sure you keep the logistics in perspective, and don't mix up calculations with conclusions/results. Also be careful with statements such as "the first method is significantly more efficient."Fuel efficient," arguable; what if the delivery truck happened to be going back and forth anyway? "Get the job done" efficient, I don't mean to be harsh but that is laughable.
If all you want to do is play a numbers game, I don't think anyone is going to object to your original post. If that's the case, feel free to use my bike messenger idea.
RE: fuel economy difference in cargo shipment
I drive a vehicle that uses about 5 gallons of fuel to travel somewhere around 100 miles, loaded or not (22 mpg in winter without A/C).
And you are going to travel 125 cars that 100 miles on a grand total of 9.25 gallons?
Wow.... I better get one of those cars.
rmw
RE: fuel economy difference in cargo shipment
RE: fuel economy difference in cargo shipment
the 9.25 gallons was the theoretical increase in fuel consumption related with a 10% increase in rolling friction.
None of this considers the increased fuel required to accelerate as well as the increased wear on brakes/clutch for hauling the added weight.
RE: fuel economy difference in cargo shipment
- Steve
RE: fuel economy difference in cargo shipment
Also a larger depot with more docks would be required to accommodate the much higher traffic flow in that area.
Regards
Pat
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RE: fuel economy difference in cargo shipment
RE: fuel economy difference in cargo shipment
We have an expression here "at that price it must have fallen of the back of a truck" which implies the driver arranged for it to fall into hands not intended by the consignor. While the odds might change, I don't think theft of goods in transit is restricted to casual drivers.
Regards
Pat
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RE: fuel economy difference in cargo shipment
RE: fuel economy difference in cargo shipment
rmw
RE: fuel economy difference in cargo shipment
- Steve
RE: fuel economy difference in cargo shipment
Regards
Pat
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RE: fuel economy difference in cargo shipment
TTFN
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RE: fuel economy difference in cargo shipment
Most freight in the US goes via hub and spoke routing, but many carriers can and do plan more creative routes, where a given truck never actually stops in a depot, and the freight may never leave its original container/trailer until it hits its delivery dock. Even UPS and Fedex use a hub/spoke system, though their hubs are typically located near airports to support express shipments; they also ship along planned routes as above, and it seems to be random whether different freight will be routed through their hubs or not (based on watching the tracking progress online). At the same time, we can ship freight as far as Oregon and it goes essentially point to point; the carrier plans a local pickup route in Seattle, and the truck (once loaded) hauls down the interstate, dropping stuff en route. Our local UPS driver can/does drop things between us and the local hub - but I think he is smarter than the average brown truck driver. We also ship nearly full containers, and these essentially move from our dock to the shipping dock, as far away as Houston. Mind you, the container (trailer) may have 3 or 4 tractor changes from here to there, as it moves though the shipper's hubs en route. So...I think it's a mix.
RE: fuel economy difference in cargo shipment
- Steve
RE: fuel economy difference in cargo shipment
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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.
RE: fuel economy difference in cargo shipment
It's now a new idea. I shipped an exhaust system to Alaska a few years ago via 'demurred freight', which basically traveled on carriers with otherwise wasted capacity, at their convenience. Took six-ish weeks from SoFla, but it was in the winter when the customer's boats weren't busy, so there was no rush, and it saved a ton of money for them.
Mike Halloran
Pembroke Pines, FL, USA