Higher MPG For Big Trucks

 

to go 100 miles, the 8mpg vehicle uses 12.5 gallons of fuel. The 10mpg uses 10. That saves 2.5 gallons and is a 20%

improvement over 8mpg.
The 25mpg vehicle uses 4 gallons, while the 50mpg uses only 2. Sure, that’s a 100% improvement, but it only saves 2 gallons.

Diminishing returns; it’s better to make the worst merely bad than it is to make the already great become magnificent.

1. Those 8 MPG tractors are still quite an improvement over the 4 MPG tractors they had back in the 60s. In the early 90s, 8 MPG was considered “fair to good”, you didn’t start getting a “fuel economy bonus” until you got over 12. I don’t know how much that’s changed in nearly 20 years, but I’ll guarantee you trucking companies are not ignoring it.

   For the record, Freightliner and Volvo have partial wheel fairings. For that matter, the Volvo in your picture has a fuel tank fairing. For the gap between the tractor and trailer, the problem is keeping whatever airfoil measure you choose out of the way when the driver is “jackin and backin” the trailer into a hole. If you see a trailer with a slight dome on the windward face, that’s what that dome is for.

   As for the compressor for the “virtual airfoil” using the Coanda effect, on a tractor at least that’s easy. The compressor is already there, for the air brakes.

   Posted by GrumpyOldFart       11/25/2009  at  10:37 PM  



2. The big part of the problem of having a fairing between the tractor and trailer is jackknifing. Not the act of a complete uncontrolled jackknife, but an extremely tight turn. Sometimes, the tolerances can be inches between the trailer and tractor, it’s especially bad when you have to turn hard on an uneven surface.
   I do know a lot of companies would love to save some money, a lot comes down to the old bottom dollar in the industry. The big question will be ‘how much does it cost vs savings we would realize’. A lot of people don’t realize that big trucks have big prices.
   A Toyota fairing may cost 6-700 for a decent quality fairing, how much for a vehicle that is 48 or 53 feet long (the 2 most popular trailer lengths) not to mention 20 feet of tractor.. Retrofitting would probably be godawful expensive.
   Most tractors now have tank fairings, and more than a few have more aerodynamic bodies, and are being made of lighter materials, since, as it has been noted, it is more economical, but the lighter materials have the trade-off of for durability and price. Which do you think will last better on an average team truck’s 150-200k miles a year? A steel brace, or an aluminum or plastic or steel brace? There are a lot of roads in this country that make a washboard look smooth, and even with a good pre-trip, the most observant driver can miss something like a cracked support.
   It’s safety versus cost.

   Just a bit of input..

   Bill

   Posted by Doctor DETH       11/26/2009  at  02:39 AM  



3. What about a device that carries 100 times that of a truck and gives 2 or 3 mpg? that would need a truck to give 200 mpg to compete, this it an old idea called a train, runs on low friction steel wheels, etc, etc. As trucks worldwide use more fuel than cars (according to UN and EU stats so probably lies) get the effin trucks off the roads and on to trains.

   Posted by Chris Edwards       11/26/2009  at  08:29 PM  



4. Trains definitely have their uses, but they can’t go everywhere.

   When I was a teenager in Higgins’ Station, OH, the trains still ran through the town.

   I lived on a farm three miles out of town and used to walk the tracks into town to visit friends. Got a little dangerous at times, depending on where we (usually my sisters were with me) were in the train came…

   Trains hadn’t actually made a stop at Higgin’s Station since before I was born. The old train depot was a mini-museum. Nowadays, even the train tracks are gone, turned into a bike path.

   Don’t bother looking up Higgin’s Station, it hadn’t been called that since before I was born either. The only place you’d find that name is on the old depot, and the bar in the dying business section of town.

   Still gonna need trucks to get goods from train depots out to the hinterlands like Higgin’s Station.

   Posted by Christopher       11/29/2009  at  01:12 PM  



5. Christopher, put the rails back, we have this dumb sight here in Ontario, pretty cycle paths and heavy trucks roaring up and down the highway.When I was young I lived in west London (UK) there was a huge depot nearby (and another 5 miles nearer the city) there the goods were tran-shipped to local deliver articulated trucks, hauled by special scammel 3 wheeled tractor units to navigate the small tight streets. This system was very good, but was killed off because of the unions supported thieving from the loads. It was all gone in the 1970s. given time the powers that be will discover the use of railways and spend vast sums of taxpayers money to re instal them.

   Posted by Chris Edwards       11/29/2009  at  05:21 PM  

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