mpg of new gas motorhomes

Started by cosmic, February 14, 2013, 08:16 PM

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Oz

It topped here in Pennsylvania at $3.05 US gallon shortly after tge election.  It's around $2.95 now.
1969 D22, 2 x 1974 D24 Indians, 1977 27' Itasca

Schmitti

I have a dream  W% .... ääääähm that would be a dream for us Europeans with these gasoline prices  :)rotflmao

Thomas
Understeer is when you see the tree, if you'll take. Oversteer is when you only hear him on impact.

Oz

I imagine so, Thomas. I imagine so. 
1969 D22, 2 x 1974 D24 Indians, 1977 27' Itasca

eXodus

I had test driven the Thor Vegas (2014-today)

And confirmed with other boards that this small 25-27ft Motorhome with the Ford V10 averages about 8.5-10mpg.

If you want to get more then 10mpg with an RV - get a Diesel. Or a Class B on a Transit Chassis with a Turbo Gasoline Engine.


RVSTEVE

So basically Thomas is saying if a liter of gasoline costs 1.45 Euros in Europe, which would equal $6.64 per gallon (1.45 Euros into dollars = $1.75406 x 3.7854 liters for 1 gallon).
LP gas in Europe per liter is 64 cents according to Thomas, which would be $2.42 a gallon (64 x 3.7854 for 1 gallon).

The drop in mpg switching to LP gas as fuel from gasoline as fuel for his Chevy 454 is 17% (9.4mpg - 7.8mpg =1.6 mpg drop or 17%),  which would mean that if he was was paying $6.64 a gallon for gasoline considering the LP fuel switch, his cost per gallon should be compared to  $5.52 a gallon figuring the mpg drop. So even with the mpg drop figured in, it looks like LP gas being used as fuel for a motorhome will decrease fuel costs by a little more than half in Europe.

Here in the U.S LP gas currently costs on the average $2.30 a gallon and considering gasoline prices are reaching for the $3.00 a gallon markif one uses the lower octane, the cost of the LP conversion may not be worth it yet in the U.S.  The savings on internal engine parts life being greatly extended by the much cleaner LP fuel, as fleet owners will attest to, along with environmental reason might be cause for making the switch. I guess how many miles one puts on their rig will be the determining factor, and how much one would have to pay for the conversion. Myself, I am going to look into making the conversion and be duel fuel. Thank you Thomas for bringing up LP gas  as an alternative.              Steve

eXodus

LP conversion has a few more benefits.


I had a LPG car in Germany, you could basically triple the miles between oil changes - so clean looked it.

LP does not go bad as Gasoline does,  which is interesting for RVs which are potential long parked.

With a LP conversion you increase your total range - LP + Gas tank. Further you expand your options of finding fuel.

You can use it in place of propane for the RV appliances.  (research that one to be safe)  so one tank to do it all :)


RVSTEVE

Yes those are good points to consider, especially increasing ones range between fuel stops with the addition of an LP tank. Myself being a person of limited financial resources, the $6,000 price tag for equipment and labor for the LP conversion  (http://www.runpropane.com) would be prohibitive.

For those that can shell out $6,000, the U.S. government will cover 50% of the costs of the conversion of any vehicle that will retrofit an alternative fuel system on their vehicle by giving  a tax credit in the year the installation was made (https://afdc.energy.gov/laws/4547), thereby dropping the investment to $3,000. Not sure if that will help anyone retired and living on a fixed income paying little taxes.

Considering all the benefits discussed, the LP gas conversion alternative should be good news to many who own an RV.                 

Steve

eXodus

That sounds high.
I saw conversion for $ 3-4k

Yet you need to drive lot for this to make sense.
Propane got expensive the last 2 years
North of 10.000 miles a year or have really bad mpg in the 5 range.




RVSTEVE

The price I quoted was from: http://www.runpropane.com/Bi-Fuel_Cars_Trucks_FAQ.html

"The cost of a system will vary depending on the vehicle and tank you choose.
A system on a 4 cylinder vehicle with a small trunk/bed located tank will run about $4000 installed. While a system on a 8 cylinder vehicle will run in the neighborhood of about $6000.00 with a standard tank."

They are probably referring to newer vehicles. If your vehicle is fuel injected and has lots of electronics the installation is probably in this range but may be on the higher side. They were the only ones online giving prices. Our classic RV's with carburetors should be significantly  cheaper to have duel fuel systems retrofitted.

Just came across this kit for DIY'ers:  https://www.propaneconversionparts.com/inc/sdetail/620/623  for $875, not including the under the chassis tank, which would probably double the price. Things are looking up for LP conversion.       Steve

TerryH

Prices in BC are gas  +- $1.50 Cdn/litre  propane +- $0.70 Cdn/litre.
Engine component cost for dual fuel conversion are considerably less for carbureted  engines than for TBI or injected engines.
For carbureted the conversion is quite simple to do yourself. Not so for injected.
Something to consider is your clearance between the air filter and hood/doghouse. With a carb engine you are adding components between the carb and air filter. The vaporiser is stand alone and usually not problematic.
With injected timing changes between the fuels is computer controlled, with carb it is manual.
When I had my shop I had 4 carbureted service trucks running dual and 2 gas only. Engine service and maintenance costs ran approx. 45% less for the dual fuel engines, all 6 were GM 350ci.
I would have them run on gas for 15 minutes per propane fill up, so I never bothered with timing changes. Primary reason for running on gas was to lubricate the rubber carb components. Propane is far drier than gas.
Further to consider is the wet weight of the tank when looking for a mounting location.
Also, at least here the fill an valve access door for the tank cannot be locking.
I believe there are state laws in some US states regarding using some tunnels if you run on propane.
It is not our abilities that show what we truly are - it is our choices.
Albus Dumbledore

RVSTEVE

Terry, Lots of good information there and your rig is propane powered. Very cool. When you travel where do you usually fill up with propane? Did you see cost savings in traveling on propane besides engine maintenance, which by itself is worth it in my book?                Thanks, Steve

RVSTEVE

Is your tank mounted underneath? Also, would be building an extended welded platform on the back of the rig with 3-100lb. tanks protected by a welded cage and heavy duty bumper be reasonable?  I happen to have 3 good 100lb. tanks so I could save a lot of money if I could use them for propane storage.              Steve

TerryH

Cost savings - absolutely. Speaking of the carbureted vehicles, better performance, starting and overall running.. I personally never experienced less power or mileage between gas and LPG.
As for my MH which is TBI, same thing.
As for tank filling, today it is not a problem here at least. Most stations offer gas, diesel and propane.  15 years ago was far different, given the nozzle required and the metering required for vehicle filling. Not sure of US availability.
As for tanks and locations of, I have a 80lb horizontal tank forward left. To utilize 3 - 100lb tanks (vertical or horizontal?) including both the tank and rack weight? I am not the right person to offer an opinion.
Regarding the very real limitations of factory installed hitches I would strongly recommend you search here for articles posted by Rick1985 on hitch concerns.
It is not our abilities that show what we truly are - it is our choices.
Albus Dumbledore

eXodus

When I had my LPG car - is was fuel injected. And that one got 20% less mpg on propane.

I think with a carbureted vehicle - those things already do not get the most out of Gasoline. So switching to MPG doesn't make a large difference.

Schmitti

Oh woe, the states seem to have a lot more to do here
We rebuilt our Thor with injection system ourselves. All parts, including the control unit, lambda probe, lines and 200l tank cost around € 2000. By the way, the tank is attached under the car. With LPG the engine needs about 5l more to 100KM - which is not really bad. LPG is still very cheap in Europe. The engine performance hardly decreases. This is only minimally noticeable in very steep mountain roads. Here are a few pictures to look at:






Thomas
Understeer is when you see the tree, if you'll take. Oversteer is when you only hear him on impact.

eXodus

Nice installation!  Schöne arbeit!

What is that metal shield on top of the engine?  Just a deflector or a different intake?

I don't drive my RV far enough for me to make sense for something like this here in the US.
Going about 5000 miles  8000km a year - @ 10mpg -  23-25L/100km 

So I'm only burning through 1900L of Fuel.  And for 20% savings you get around here on fuel price, I could just drive slower :P

But your 454 needs probably what ? 30+ L/100km ?

Schmitti

Thanks :)
The aluminum sheet is simply chosen for easier assembly. All 8 nozzles are mounted on one level instead of all of them being mounted individually. Accordingly, only a simplification of assembly  ;)
The 454 only needs the 30L with LPG. On gasoline, at a constant 95KmH "only" 24L. The conversion paid off in our prices and our performance in the first year.

Thomas
Understeer is when you see the tree, if you'll take. Oversteer is when you only hear him on impact.

udidwht

Quote from: RVSTEVE on April 25, 2021, 02:08 AM
So basically Thomas is saying if a liter of gasoline costs 1.45 Euros in Europe, which would equal $6.64 per gallon (1.45 Euros into dollars = $1.75406 x 3.7854 liters for 1 gallon).
LP gas in Europe per liter is 64 cents according to Thomas, which would be $2.42 a gallon (64 x 3.7854 for 1 gallon).

The drop in mpg switching to LP gas as fuel from gasoline as fuel for his Chevy 454 is 17% (9.4mpg - 7.8mpg =1.6 mpg drop or 17%),  which would mean that if he was was paying $6.64 a gallon for gasoline considering the LP fuel switch, his cost per gallon should be compared to  $5.52 a gallon figuring the mpg drop. So even with the mpg drop figured in, it looks like LP gas being used as fuel for a motorhome will decrease fuel costs by a little more than half in Europe.

Here in the U.S LP gas currently costs on the average $2.30 a gallon and considering gasoline prices are reaching for the $3.00 a gallon markif one uses the lower octane, the cost of the LP conversion may not be worth it yet in the U.S.  The savings on internal engine parts life being greatly extended by the much cleaner LP fuel, as fleet owners will attest to, along with environmental reason might be cause for making the switch. I guess how many miles one puts on their rig will be the determining factor, and how much one would have to pay for the conversion. Myself, I am going to look into making the conversion and be duel fuel. Thank you Thomas for bringing up LP gas  as an alternative.              Steve

In reality a peak tune 454 TBI RV will get between 7.5 and 8.5 mpg (US). If one is getting 10+ they aren't factoring in a lot of downhill/tailwind time with the foot out of it.
1994 Fleetwood Southwind Storm 28ft
P30 454 TBI w/4L80E VIN#1GBJP37N4R3314754
78,XXX US as of 8/2/23

Oz

No political comments, period.  This is clearly stated in the community rules along with any and all contoversial social topics.

We are here to share the vintage RV experience.
Anyone wanting to express their opinions on contoversial, social  topics... facebook definitely is the place for you.

1969 D22, 2 x 1974 D24 Indians, 1977 27' Itasca