I had a quick drive though the Ozarks today and got to thinking about Air Hybrids and how easy they would be to build into a pickup...

Heck, you don't even have to modify the engine... just add a pneumatic motor/compressor externally to start with and then integrate it in the next big round of changes. It could act just like a Jacobs brake and completely disconnect when not in use... when you downshift and tap the brakes, the pneumatics kick in as a compressor and fills the tank... When you have enough pressure, the pneumatics run as a motor in parallel with the engine and boost fuel mileage.

I was also thinking that if used on a semi, this would cause quite a few of those "no engine brake" signs to start falling, and allow drivers to use their rigs like they are meant to... since the compressed air is not released to the atmosphere, neither is the sound of the rapid decompression when the braking valve opens.

 

I'm not 100% sure, but I think on a stock engine, it would work poor because of the compression stroke.

Maybe it would be better to use an external pump....the engine also can only pump to a certain pressure-

Only problem is that a pump behind the transmission is going to work not as nice.

 

They have been making and selling E450 hybrids with as small as 158” wheelbase that have the traction motor between the transmission and the rear axle. A small shaft from the transmission to the traction motor and another shaft from the traction motor to the axle. Fuel economy improvement ~39%

On my 99 F250SD, I figure there is greater than 7' between the back of the transmission and the rear differential (assuming I read the tape measure correct in the dark). You could fit two 55 gal drums in that space.

 

Thats a pretty large system, and it looks like it's meant for slower stop and go traffic, like a bus route.

 

I was sitting here thinking about all of this PHEV stuff and had a thought. I have a 99 F250SD 2 valve 5.4L V8 with 260 hp. Moreover, I have towed a 9000 lb. trailer load of hay at highway speeds with it. My combined truck and trailer load of hay puts me in the GVWR range of these medium duty vehicles. Now convert 260 hp to kilowatts. The conversion if I remember correctly is 1 horsepower = 0.746 kilowatt. So, I get 194 kilowatts.

The E450 balance hybrid system uses a 100 kilowatt motor. Therefore, an induction motor (the traction motor) of twice the power used in the E450 hybrids, 200 kilowatts, would give a bit more horsepower than my 2 valve 5.4L V8. Oh, you also get the torque benefit of the electric motor. Now if you only want to go 30 mph full electric you would not need 260 hp (assuming light acceleration). Stomp on it and the 6.7L diesel gets a horsepower and torque boost by electric assist.

Hey, but I am just speculating on all of this based on my knowledge of what has been developed, produced, and is under development. I could be totally wrong on this the PHEV system for the F550. It may have very little in common with the balance hybrid electric system. ---Fun to discuss nonetheless---

 

Interesting yes.

I think we're still a far ways from seeing mass produced hybrid super duty trucks though.

 

I was in Seattle this year, and took a Prius as taxi from the airport to the hotel. The driver said that he had over 300,000 miles on it, original battery, and still got over 50 MPG.

 

I seem to recall that early-on, Toyota set up some kind of battery exchange program. I think they were also refurbishing used Priuses (Prii?) with new batteries, and reselling them. Maybe that's not necessary anymore.

 

300,000 miles on taxi is about 3 years, batteries should last 7 or more.
But why that should matter for average Joe making 12,000 miles a year?

 

The engine braking can pump just couple hundreds psi, what doesn't store much energy unless you have like 1000 gallons tank.
The air starters/emergency supply operate with like 3000-5000 psi. Totally different animal and safety issues.

 

Posted by mistake, sorry.