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RustyJC · 10-15-2008, 06:23 AM

See HERE.

Rusty

RustyJC · 10-15-2008, 06:23 AM

See HERE.

Rusty

DriVer · 10-15-2008, 07:22 AM

Thanks Rusty!

We might even see Navistar and Workhorse announce a Hybrid RV Chassis in the not too distant future. It will all depend on how it could be integrated into an RV chassis and then cost vs performance.

This sounds like an exciting prospect for RVs going green(er)!

Jestme13 · 10-15-2008, 11:56 AM

This sounds very doable for the RV industry. The UFO would be a perfect candidate with all that pass through storage for the battery packs.

I wonder why no one is looking at diesel electric combinations, like locomotives. Imagine a small Kabota driving a strong alternator or generator.

Gary RVRoamer · 10-18-2008, 06:52 PM

Unfortunately Hybrids aren't of much value in long haul (over the road) driving and that mostly what RVs do. Note that these new Navistars are intended for city delivery applications, i.e. short haul, stop and go.

But with the amount of fuel large trucks consume, sooner or later some genius will come up with a way to power large engines with less expensive fuel. Or at least a fuel that is in larger supply than petroleum.

porscheracer · 10-18-2008, 07:34 PM

As RV Roamer indicated, hybrids are pretty useless as predominantly on-highway vehicles. The problem is: to push a conventional 40' Class A down the road at 60 MPH takes approximately 175 constant horsepower. This is out of the realm of current, affordable, hybrid units.

The hybrids perform well in city driving by harnessing otherwise unused power while the vehicle is operated at well under load maximums - idling through traffic and such. Thet's why hybrids get phenomenal city mileage, but essentially unimproved highway mileage over their conventional counterparts.

Diesel electric locomotives (trains) use the electric motors as a transmission - not because of efficiency. There is an efficiency loss in both the generator and the motor (totaling ~30%). They would actually get better economy if they could come up with a direct drive system.

RustyJC · 10-18-2008, 08:18 PM

Agreed - the hybrid system doesn't offer much for flatland highway applications, but it is green technology that's making its way into the heavy vehicle marketplace.

Where it could have some value is in mountain driving where the electric motor could provide bonus power on the uphills and the regenerative braking could recharge the batteries on the downhills.

Rusty

porscheracer · 10-18-2008, 09:39 PM

Rusty . . . yup!

I was thinking about that very concept about 3 weeks ago when we were paddling around Colorado. Actually, about a 100HP motor / generator doing nothing but regenerative braking and power - with a huge battery pack! Maybe a 50HP attached to each FRONT wheel - rudimentary 4WD, even!!

RustyJC · 10-19-2008, 03:07 AM

OK, here are some musings of an old, broken-down mechanical engineer over his morning coffee...

Building on the discussion over mountain driving, what a hybrid package could do is allow the use of a smaller diesel engine that might (depending on the BSFC curves) deliver some fuel economy advantage. Instead of a 450 HP diesel engine that's using only, say, 250 HP during steady-state cruise, a coach could use a 300 HP diesel and a 150 HP electric motor/generator to achieve somewhat equivalent performance (the weight of the motor and battery packs would be a disadvantage here) in the mountains while perhaps offering improved fuel economy in the flatlands. That might be worth some mathematical modeling by the engine and chassis manufacturers...

Rusty

DriVer · 10-19-2008, 03:37 PM

I was at my Saturn dealer a couple of days ago and my saleman said to wait for a "Dual Stage Hybrid" like a Chevrolet Volt.

Plug in your motorhome at night to recharge the batteries ????

Jestme13 · 10-20-2008, 07:19 PM

Rusty, your idea is teetering on my thoughts about a diesel electric combo, (locomotive style) use power through a common Transmission, or, use direct drive motors on all wheels. There are a ton of approachs that deserve more thought. We justn need to shift the current paradyme.

Bob (WA0MQE) · 01-11-2009, 02:06 AM

Does anyone remember the article in Popular Mechanics, or Popular Science back in the 60's where they stripped all the running gear out of a Army 6X6 truck and in place of the transmission they installed a generator and then 6 electric motors, one on each wheel. The original 6-cylinder engine powered the generator. Of course they didn't mention miles per gallon, because back them fuel was cheap.

It may or may not have made any difference in mileage but it sure had power and really good traction.

Also, regarding the hybrid issue in reference to large trucks or motorhomes... on recharging the batteries you could turn a large portion of the roof on these vehicles into a really good solar array to help recharge the batteries. You wouldn't need separate house batteries either, just a regulator to adjust the voltage to the coach needs.