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Dec 3 07 12:00 AM

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We have a TT now and it will be at least a couple of years but I can see us moving up at somepoint and a Class A is definetly a possability at some point. We've noticed a HUGE price jump when looking at class A's when you go from a "cheaper" gasoline version and then jump to a diesel pusher class A. Most of the newer ones we've seen seem to all use a Ford V10 powerplant with OD and all that and most offer the Chevy 8.1 gas motor as an option. Curious what kind of gas mileage these things woudl get with the V10 gas motor in a 32-36 foot class A Bus size RV? What about the diesels in this size range?

2003 Jay-Flight 27BH travel trailer
1994 Red Chevy 4 door long bed 6.5TD Dually Tow Rig

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#1 [url]

Dec 3 07 12:25 AM

I did a little research and I may have answered my own question. For the most part it seems the V10 gas coach's tend to average around 6.5-7 mpg while the larger, heavier, nicer, more expensive diesel pusher coaches average around the 8.5 to low 9's. While the diesels do offer ammenities and comfort advantages (while driving) compared to a front engine gaser, most "experts" seem to agree that a gas powered motor home should be at the top of your short list in the 35 foot and shorter class unless your really pickey or really have a taste for the higher end luxury and price tags. For 2 mpg difference, looks like gas is the way to go in my mind.

2003 Jay-Flight 27BH travel trailer
1994 Red Chevy 4 door long bed 6.5TD Dually Tow Rig

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jasoncarder

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#2 [url]

Dec 3 07 11:27 AM

My in-laws have a 2007 34-foot Holiday Rambler diesel pusher, and they average 12 mpg (and that's towing a vehicle behind them). From what I've read, a comparable front-mounted gas engine would average around 6 mpg. On top of that, the diesel engine will probably just be getting broken in when the gas engine hits the end of its useful life. If I were in the market for a Class A, I would have to be able to test drive a gas engine before I even considered one. I imagine that a 34 foot bus towing a small car with even a V10 gas engine (much less the GM 8.1) would struggle in the terrain around here. I've never driven my father-in-law's "A" (nor do I want to), but I've been behind him, and he could easily maintain 75 mph on the interstate if he wanted to (he doesn't, FWIW). I guess my point is that there is a reason why gas-engine-powered Class A's are less expensive than their diesel counterparts.

Jason, Erin, William (born 10/09), and Rosie the 50-lb lap dog
2004 GMC Sierra
2000 Bantam Trail-Lite B-17 Hybrid
Gray, TN

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#3 [url]

Dec 4 07 12:39 AM

Hotrod, one of the major things that will effect fuel mileage is how fast a person drives. I am sure you already know that. I read an article in one of the RV magazines once that showed how the wind resistance changes as speed is increased. The resistance changed tremendously once 55 mph was reached as the speed went higher. At one point, the resistance squared in only 5 mph difference. I try to drive in the low 60s even on the interstates. I have a 35 foot class A that has the Cummins 5.9 liter and it is turbo charged with the Allison 542 transmission. The 542 is not as fuel efficient as the later model Allison 2000 and 3000 series transmissions. I average getting 11 mpg with mine on trips. It would not get that if I drove at 70 mph and did stop and go driving. One thing about a gas engine in a larger class A is with the gearing, the engine works really hard and runs at higher rpms than in smaller vehicles. I have seen in some forums that people say that the engines in a larger class A gas motorhome probably will not last much beyond 50,000 miles. I have no idea if that is a true statement. One thing that you normally find in a diesel powered class A is more weight carry capacity, is heavier built and stronger brakes than in a gas powered class A. One the big differences to me is the rear engine powered motorhome is much quieter in the front than a front engine powered motorhome. We had a gas powered class C once and we got lots of heat and noise from the engine and I assume that would be the case with a gas powered front engine class A also. By the way, they have built rear engined gas powered motorhomes in the past. I don't know if anyone is currently doing that or not. Another factor, a used diesel motorhome has a higher resell value than a gas powered one. I hope my explanation is not too fuzzy.

Here is some discussion about fuel mileage in a forum where some of the motorhomes are really heavy ones.
http://www.rv.net/forum/index.cfm/fuseacti...43.cfm#20550243

Located in Church Hill, TN
I have been RVing/camping in some form since about 1966.
13 Nights spent camping in 2009 so far
82 Nights spent camping in 2008

2003 Dodge 3500 Cummins Turbo Diesel
2005 Lance 1181
35J Bounder Cummins TD motorhome

To learn about Truck Campers go to:
http://www.truckcampermagazine.com

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#4 [url]

Dec 5 07 8:53 AM

Thanks guys for the info. RV.net is where I looked also and saw so many responses to form the averages I listed above. Of course there are differences with some getting 2 mpg better than anyone else simingly. A guy here at work has a 34' V10 Class A and says he gets 10mpg with it.

I agree the diesel has to be better overall for many other reasons, but in a fuel mileage comparison there really seems to be very little difference between gas and diesel. I'm really not too concerned about longevity as most coach's will never see 100K miles on them anyway. They just aren't driven that much unless you are a full timer. I figure 5K miles a year would be a very high average for one, at least in my use.

I've noticed the mpg increase with my TT when I drive 55-60mph vrs 70mph. Definetly makes a big difference.

2003 Jay-Flight 27BH travel trailer
1994 Red Chevy 4 door long bed 6.5TD Dually Tow Rig

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#5 [url]

Dec 5 07 11:54 PM

Actually Hotrod there really is a big difference it mpg in diesel and gas given that everything else is the same. By that mean if weights are close, speeds are close etc. the diesel will get much better mpg unless something major is wrong. Some people with the big diesel motorhomes state that they are getting 7 to 8 mpg. But if you take into account they are moving 30 to 40 thousand pounds, that shows a big difference if compared to a motorhome weighing say 18,000 pounds. Another thing is I have seen people use one tank for MPG data. That just can't be done. Every fillup should be taken into account and an overall mpg rate be determined. A few fillups just won't give you accurate results. I have heard some wild claims about fuel mileage. Sometimes I think people might be using a crooked pencil to figure their mileage.

Located in Church Hill, TN
I have been RVing/camping in some form since about 1966.
13 Nights spent camping in 2009 so far
82 Nights spent camping in 2008

2003 Dodge 3500 Cummins Turbo Diesel
2005 Lance 1181
35J Bounder Cummins TD motorhome

To learn about Truck Campers go to:
http://www.truckcampermagazine.com

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#6 [url]

Aug 24 09 12:45 AM

We have a 35 ft. National Sea Breeze. I have a ScanGauge II and it says I get around 7.5 towing my Saturn Vue. I get 8.2 not towing. Mountains make a lot of difference. Towing from Kodak to Catrhage heading to Defeated Creek we get 7.5 towing, and from Kodak to Hot Springs, NC which is only 58 miles from the house it drops to 6.5 towing.
Just made a trip from Kodak to Flagstaff AZ and averaged 7.9 acording to the gauge.
I stay around 62 and very, very seldom go over 65 (Saturn Limit on Towing with Automatic Trans in the Vue).
Good luck.

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#7 [url]

Aug 24 09 9:31 AM

QUOTE (DakotaD @ August 23, 2009 11:45 pm)
We have a 35 ft. National Sea Breeze. I have a ScanGauge II and it says I get around 7.5 towing my Saturn Vue. I get 8.2 not towing. Mountains make a lot of difference. Towing from Kodak to Catrhage heading to Defeated Creek we get 7.5 towing, and from Kodak to Hot Springs, NC which is only 58 miles from the house it drops to 6.5 towing.
Just made a trip from Kodak to Flagstaff AZ and averaged 7.9 acording to the gauge.
I stay around 62 and very, very seldom go over 65 (Saturn Limit on Towing with Automatic Trans in the Vue).
Good luck.

That seems to be pretty good mileage towing. I assuming the low mileage to Hot Springs was going through Newport, with the traffic lights.

Coolbreeze1

Coolbreeze1

05 Chev. Dually 3500
08 Crossroads Cruiser 5th wheel

Nights Camped in 09......16
Nights Camped in 10......18
Nights Camped in 11......3

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#8 [url]

Aug 24 09 10:50 PM

One option you might want to consier is a FRED(FRont Engine Diesel). Tiffin motorhomes out of Alabama I know builds them. They use a 6.7 Cummins I believe mated to an Allison tranny. They do cost more than a gas, but less than a pusher.

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2008 Jayco Designer 35RLTS
2012 Ford F-350 DRW King Ranch

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