"Big rigs will have to slash fuel consumption by 23 percent".

[gone-ot]

...any bets as to *how soon* the engine/cabin designs of 18-wheelers will start looking more "egg-shaped" for better aero?

[drv2die]

aero isnt always an option for some truckers. you try driving one of those fiberglass front end trucks through the woods to get to the loader, you will never make and then when it rains and you get stuck the skidder has to have something to drag you out by. my family has been in the logging buisness my entire life. i remember being 14 and running the knuckle boom.when i turned 16 i was on the saw. dont think we dont think about economy that truck has never seen over 60 mph. but that doesnt mean that those otr guys do need updated trucks.

[p38fln]

*everything* i've said is based off OTR trucks - i've not been around off road equipment enough to have an opinion on that one

[redneck]

Aero improvments on vocational vehicles are useless.

However...

It would be interesting though, to see someone aero mod a Garbage truck...

>

[BHarvey]

Saw one today that had full moons, side skirts on the trailer, and a pretty large boat tail.

The air behind it was much quieter.

Looked very cool!

[oil pan 4]

Originally Posted by redneck

I doubt a 23% reduction across the board is possible. Dump trucks,Cement mixers,log trucks and Heavy equipment haulers will always use more fuel. Bad aero, heavy loads and short hauls on secondary roads with lots of stops, just eats fuel.

Also, open flat bed trailers with their constantly changing load configurations.

>

It was:
23% for big rigs
10% for what I understood to be 3/4 and 1 ton gas pickup trucks
15% for diesel pickup trucks
9% for Dump trucks,Cement mixers, delivery vans, fire trucks, trash trucks and everything that has little to no "standard".

[user removed]

This chart is a projection from the EPA hydraulic hybrid research in 2006 for a Class 2b truck.

The fuel economy increases by over 300%.

This was a cooperative program with Ford, Eaton, the Govt, and the University of Michigan. Not what you would call a bunch of ignorant Morons.

regards
Mech

[p38fln]

The hydraulic systems are awesome from what I've heard - they're hybrids without all the mess of batteries Excellent for trash haulers

[Clev]

Could the hydraulic accumulators also be used to supply power to the existing hydraulics, i.e. compactors, liftgates, etc? Listening to an idling diesel rev up just to compress some trash really grinds my gears.

[user removed]

The 2006 EPA work concluded that there was the need for "clean sheet of paper" design for a hydraulic pump motor that would replace the bent axis design used in their modeling and prototypes. They had a 3800 pound test mule that got 80 MPG average and the converted a Ford SUV as well as a group of UPS delivery vehicles to HH configuration.

The INNAS Hydrid shows a direct comparison between conventional and HH configuration. They also address the issue of lower efficiency in hydraulic drives compared to gears, which is offset by limiting engine operation to only the sweet spot of BSFC, since the drive is from the accumulator instead of the engine directly.

One of the problems with the EPA design that was addressed in the INNAS version was to put the drives in the wheels themselves. EPA's version drove the differential in the same manner as the propeller shaft. This meant that pump RPM was 3.5 times higher than direct in wheel drives.

Even with all the flaws the wheel to wheel efficiency was closing in on 80%, while electric regeneration involves many more steps and cumulative losses as well as the fact that you simply can not put current back in a battery at anything approaching the rate it can be applied.

Another point to understand is the configuration of an electric motor and battery for charging the accumulator. This eliminates the expensive controller from the equation since all you need is an on and off operational tactic for accumulator replenishment. This may be the final configuration since battery longevity can be enhanced by gradually discharging the battery instead of many cycles of draining and recharging when the battery attempts to become the capacitive storage of every system energy fluctuation.

Time will tell if the hydraulic option becomes a practical solution. Understanding that a single 60-0 stop wastes the energy that could drive the vehicle .7 mile makes it easier to comprehend that like the 1 st generation Insight, it's not a long range battery that you need, it's one of sufficient capacity to store and release one full braking or acceleration event.

regards
Mech