Freightliner shows "EcoFred" Hybrid motorhome chassis

[Gary RV_Wizard]

By definition, you get zero MPG when you are idling and not moving.

The instantaneous mpg is zero, but the effect on the average mpg is negative, since fuel continues to be consumed while the total miles remains the same. If you spent a half hour driving at, say 20 mpg, followed by a half hour of idling, the average for the hour goes down to something less than 20 mpg. Ergo, one can say the idling mpg was "negative".

Its all a matter of perspective. 

 

[KodiakRV]

...Its all a matter of perspective. 

That's true. So bear in mind that when you are sitting there idling in Ocala, you are really zipping along at 907.5 mph with respect to the center of the earth.  We should all be happy with that kind of gas mileage. 

 

[Gary RV_Wizard]

you are really zipping along at 907.5 mph with respect to the center of the earth.

That why we always hear a breeze blowing through the tops of the towering Sand Pines. 

 

[rjf7g]

I notice Winny says 7%. Most hybrids exhibit their good mileage driving around town where the brake "charger is recapturing energy but mileage drops on the highway where engine has to run to supplement bateriries.

Since most of our RV driving is on the road I wonder what the fuel savings will be under actual conditions.

I am with you...7% doesn't seem like much.  I wonder what the basis is for the estimation.  I also wonder about total cost of ownership over a 10 - 15 year period and the availability of service from qualified technicians with available parts.

 

[Len and Jo]

Really have to wonder if a "hybrid" RV that is driven long distance is cost effective.

Passenger car hybrids make their gain from:

1.  turning the engine OFF when stopped.  No gas used idling
2.  the battery charging when braking.
3.  a smaller gas engine for highway speeds.  the required pick up provided by the gas engine in combination w the electric motor.  most car engine size is controlled by desired pick up and not power required for 60/70 mph cruising.
4.  the Prius  NiMH batteries has been used now for 10-11 years I think.  Granted the vehicle volumes were small 10 years ago and of the million sold to date probably most were build in the last 2-4 years.  U.S. Prius batteries have an 8 year warranty and do appear to be meeting expectations.  To extended battery life (ie: warranty $$$$) Toyota as U.S. software program recharging the NiMH batteries so that battery charge does not drop below 40%.

It would seem that little if any of the above would apply to RV.....except in the advertising and sales area. ;D ;D

 

[Gary RV_Wizard]

Note that Freightliner is not pushing the hybrid concept for motorhome chassis and no attempt was made to show that it can improve fuel economy. The ECO-FRED concept vehicle was done solely to demonstrate that Freightliner Custom Chassis is willing and able to work with motorhome manufacturers to develop alternate technologies.

Diesel-electric (as in RR locomotives) seems like a more likely alternative to me. That's another way to provide ultra high torque on demand while sizing the engine for cruising rather than peak acceleration loads.

 

[ustaxmaster]

It seems that most here are thinking that these RVs are supposed to operate exactly like the Prius. Actually, they are not. The hybrid part of this works as a boost to the ICE (Internal Combustion Engine) with extra power when needed. They would also power the vehicle when in the RV park and you are only doing 10 or 15 mph. Check out this link for a company that does conversions: http://www.salidaconversions.com/index.html

I want one of these RVs. Articles I have read say an increase in mgp from 7 to 47 percent. My research says 10 - 20.