Class A Fuel Mileage

[RFYeager]

I am trying to find out the average fuel mileage for the new Tiffin Allegro Red 34 Diesel. It has the 340hp Cummins with the Allison 2500 transmission. However, it only has 660lb.ft. of torque (probably due to the gearing of the Allison 2500). I tow a Grand Cherokee, which is approximately 4200 lbs. Just trying to make general comparisons when I go to look at buying a new (or different) RV.

I thought that wouldn't it be great if there was a forum or some type of chart where members can post their fuel mileage experience? I understand that everyone's driving styles are different, at different elevations, at different temperatures, etc. I'm just talking about a general average.

For example, I have a 2007 Fleetwood 38V with a CAT 300hp diesel and a Allison 3000 transmission. I get on average (towing my GC) 7.2 mpg. without the Toad, 7.7mpg. These numbers are driving with my cruise control set at 62mph.

[RFYeager]

dubdub07 wrote:

mowermech wrote:
IMO, if you are worried about fuel economy you probably should not be thinking about a motorhome of any type or size!

Ad nauseam. There are great opinions out there! This is not one of them. Telling someone not to worry about their MPGs is like telling McDonalds not to worry about the cost of a 7 cent cup. Why worry about cents when you make billions? It all most certainly matters in the end, but then again we already covered this quote; ad nauseam. Obviously the OP doesn't "IMO" your attitude on MPG, or they would not have asked....

Thanks...exactly. Thank you to all who posted. My question wasn't which motorhome gets the best fuel mileage, what I was really fishing for was that the Tiffin Red 34 has a 340HP Cummins but yet only has 660lb.ft. of torque. My guess is that the loss in torque would be made up in fuel mileage. Additionally, with the Allison 2500 transmission, the Tiffin Red 34 only has a tow capacity of 5000lbs.

I was just looking to see what others are getting for fuel mileage with the engine, transmission, torque, etc. set up that they have.

I will definitely look for a Tiffin forum and see what the trade offs are. I may even call Tiffin and see if the Red 34 comes with a Allison 3000 instead of the 2500. Thanks again.

[dubdub07]

mowermech wrote:
IMO, if you are worried about fuel economy you probably should not be thinking about a motorhome of any type or size!

Ad nauseam. There are great opinions out there! This is not one of them. Telling someone not to worry about their MPGs is like telling McDonalds not to worry about the cost of a 7 cent cup. Why worry about cents when you make billions? It all most certainly matters in the end, but then again we already covered this quote; ad nauseam. Obviously the OP doesn't "IMO" your attitude on MPG, or they would not have asked....

[Snomas]

I just got 7.6 mpg going from Albuquerque to San Diego towing 4800# Explorer and cruse set on 65 mph most of the way. I have gotten as high as 9.9 and as low as 6.6 depending on terrain, wind, and speed. Sometimes the tank doesn't seem to fill all the way, maybe due to air causing back up in tank!

[mowermech]

IMO, if you are worried about fuel economy you probably should not be thinking about a motorhome of any type or size!
Long ago, I kept a Log Book in every rig, and religiously entered every bit of gas and oil the rig consumed. I still keep one in the motorhome, but it is for a record of where we have been more than to record the non-existent "fuel economy".
As previously stated, when it gets down to 1/2 tank, I start thinking about where to fill it and where to spend the night.

[wny_pat1]

Sure is quite a benefit to having a old 6BT mechanical 5.9 Cummins - getting a consistant 10+ mpg in the motorhome with toad behind it.

[DaveKirby]

7.5 on my C7 cat towing a cherocar, 8.5 with a tailwind going downhill 😉

[Executive45]

My 'average' is a conservative 19.5 MPG combined city and freeway driving.....Dennis


Eight for the coach and 31 for the toad...it's all in how you word it. see how I slipped the word 'combined' in there..?...:B.....D

[chili_s_trip]

dubdub07 wrote:
tinkerer, same here! We have found that there are a lot of different factors when rolling down the road. The nice thing about the big diesels is the the +/- is relatively small no matter what you are towing. I haven't seen as low as 5.5, but a strong headwind going uphill gave me 6. Normal conditions, we stay right in the mid 7s. My truck pulling a FW stayed between 9-10. So when we did the math, the 2.5 mpg difference didn't equate to much and having 100 gallons of diesel vs 34 is huge! I like not fueling unless I want to!

For those that keep feelin the need to pipe in and ask why, I too want to ask why? If you think the OP doesn't deserve your response, don't give it! Ever get a check in the mail for 17 cents? The accounting always matters and if someone owes you 17 cents, they will pay postage, print and paper, just to get it to you because the books must be right. Same thing when figuring costs on RVing, everything matters and I agree with the OP and I DO track my mileage. If you start getting 5 and always got 8, something is wrong! I think it is important to know all the costs. It is smart. Why post otherwise basicially telling the OP they are silly for wanting to know?

X2

Why! To brag that cost doesn't mater to them. Whoopty do!
A few people on this forum are on a fixed income and watch costs very closely. I track mileage with scan gauge and adjust speed to maximize mpg. I feel good about the $300+/yr I save. Thanks.
Jack H

[dubdub07]

tinkerer, same here! We have found that there are a lot of different factors when rolling down the road. The nice thing about the big diesels is the the +/- is relatively small no matter what you are towing. I haven't seen as low as 5.5, but a strong headwind going uphill gave me 6. Normal conditions, we stay right in the mid 7s. My truck pulling a FW stayed between 9-10. So when we did the math, the 2.5 mpg difference didn't equate to much and having 100 gallons of diesel vs 34 is huge! I like not fueling unless I want to!

For those that keep feelin the need to pipe in and ask why, I too want to ask why? If you think the OP doesn't deserve your response, don't give it! Ever get a check in the mail for 17 cents? The accounting always matters and if someone owes you 17 cents, they will pay postage, print and paper, just to get it to you because the books must be right. Same thing when figuring costs on RVing, everything matters and I agree with the OP and I DO track my mileage. If you start getting 5 and always got 8, something is wrong! I think it is important to know all the costs. It is smart. Why post otherwise basicially telling the OP they are silly for wanting to know?

[tinkerer]

There are so many variables to motor home mileage that it it isn't even funny. With my Discovery with a 330 Cat I got 11.5 driving 75 mph. Sounds good, but I failed to mention that this was with a great tail wind and going down in elevation. So I could brag that I get 11 mpg driving 75 mph. But in reality I usually get 7- 8.5 mpg pulling a 20 ft car trailer at 65 mph. I have gotten as low as 5.5 bucking a severe head wind. But most people don't like to talk about those days. I traveled with a person with a F150 Ford with a 5.4 pulling a 27 ft toy hauler and he could barely get 6 mpg. Usually people with F150's brag they get 20 mpg. But pulling a load takes;) BTU's and BTU's take fuel!;)

[workhardplayha1]

Is there a mystery RV out there that gets good mileage? I think you can look at any Class-A, B, or C, any travel trailer or 5th wheel and expect to get anywhere from 7-10 MPG with very few exceptions. If the difference of 3 MPG is going to break the bank perhaps an RV is not for you?

[randallb]

Our 08 HR 34SBD with the 340/660 hooked to a 2500 got 9.8 on its last trip. It is 745 miles from my house to Lazy Days in Seffner. I sold it to them. The RV was empty except for me and 3 days of food. Filled the tank, hit the road and the fuel gauge was pegged on empty when I pulled in. It was so empty when I was sitting at the light at the top of the off ramp I was hoping that it would not run out of fuel. I really stressed when I missed the turn in to the sales area and had to turn around at the CG. With our trailer and car on the back (3000#) we usually got around 9.
Randy

[nbargolf]

Steady 8 mpg towing a Honda crv. 40 ft 360 isc cummins rolling condo. Not great but much better than 6 in our previous 34 ft with a v10. We really don't think about the mileage, it's part of the life we love and stay 1-3 months here then there then anywhere we want.

[LennyH]

Let me just say this, If your concerns are about Fuel mileage, You should have consisted that before starting Rv’ing, With that said Lets just say 65% of the cost of your RV Travels Will be Fuel. 😞

Happy Camping

LennyH

[DeWat]

Mr.Mark wrote:

Just curious, why would your ISL have only 380 hp? Our ISL has 425 hp.

For comparison to the OP, we weigh just over 40,000 lbs. and have averaged about 7.0-7.2 mpg over 65,000 miles pulling a 3,400 lb. toad. I like going about 60 mph.

MM.

What I have heard (but not confirmed) is that Cummins has dropped the ISC rather than recertifying it to the EPA standards for the new model year. So now they have "toned down" ISLs to replace the no longer manufactured ISC.

What I do know is that for 2014, all 40 foot and under Phaetons have the 380HP ISL as standard. The good thing about that is for $$$$$$$, you can now flash your 380HP ISL up to 450HP (not for me). This is already being "exploited" by dealers who are offering higher HP Phaetons brand new off the floor (Tiffin Phaeton Mountain Tamer Edition Class A Diesel Motorhomes).

So to put this back in topic area, I haven't had my Phaeton in any of the western mountains yet, but I'm extremely happy with the performance of my 380HP in the eastern mountains. I'm am not about to pay $2,500 - $3,000 just to flash my ISL so I can get better, but unneeded HP, and pour more $$$ out the tailpipe.