cummins mileage?

[Big Butt]

I have a 2010 Winnebago Journey 40 L with 360 cummings engine. What type of mileage should I expect? I use cruise set at 62 mph? Getting about 7 MPG

thanks

[MSHappyCampers]

Our MH has the Cummins ISC350 engine and we get about 8 MPG average. BTW, there's no "g" in Cummins! Very common mistake. I see it all the time.

[Big Butt]

thank you I should have listen to spell check. How are some people getting 10 to 12 mpg with a 400?

[GaryKD]

Their not getting that mileage. For the most part there is much more to these stories than is being told.

I'm traveling with about 37.5K lbs. of total weight. ISC 330 is the power plant. I travel at 60 MPH and average 7.5 MPG. Things can vary due to wind, terrain, speed and other items.

[doc]

Gary is right. We are heavy and have a 425 Cummins. Eight mpg would be pretty darn good overall. More like 7 to 7.5 and again it could be better but more often worse. It is amazing (to me at least) how much a tail or head wind will change mileage

[danes-on-tour]

Originally Posted by Big Butt

How are some people getting 10 to 12 mpg with a 400?

We have an ISL 400 engine, and we have once managed an average of 10 MPG on a tank, but we average around 8.5 MPG.

There are a few factors that comes into play when we say 10 MPG:

1: The way we measure is that we fill the tank up completely, and then check how many miles we have done since the last fuel stop. Then we do our math using these numbers. This is not a "safe" way of doing this, because it will very much depend on how the MH was positioned when we made our fuel stop. If the MH is leaning away from the fuel pump we get more fuel into the tank, as opposed to when we are leaning towards the pump. Big difference in how many gallons we can cram into the MH.

2: The time we made 10 MPG we drove around 600 miles across lovely Texas, and we had a fantastic strong tail wind all the way/day. This makes a HUGE difference to our MPG calculation.

3: We had Cummins fit the Horton fan to our engine. We believe that this add positively to our MPG calculation - not a lot, but some.

One factor, from which you can't benefit, is the overall weight of the MH. I am sure that it must make a difference if the MH is close to empty as opposed to ours which is close to full loading capacity.

Another factor is your toad. If you are not towing, I am sure this will increase your MPG.

For the above mentioned reasons, I can not completely dismiss that you could reach 12 MPG once "in a blue moon", but if you said that this was around your average with a toad and fully loaded, I would expect to see your nose grow (Pinocchio ) as and when you told me.

[Skip426]

Originally Posted by Big Butt

. How are some people getting 10 to 12 mpg with a 400?

As other posters have said , you need to add the word " claiming " to the high MPG numbers.
Quick story. An RVing buddy ; Chevy lover ; always claimed he , with his 8.1, 3/4 ton 4X4, was getting 2mpg better than my 8 L V-10 Dodge 3/4 ton 4x4 towing. Caught him one day, we filled up the night before at the same station, drove till noon, the next day with our 5ers , never out sight of one and other. Filled at the same station when we stopped for lunch. I took 2L,( 1/2 gal ) more than he did and my trailer weighed 3,000lbs more.
Fuel economy never came up in conversation after that.

[YC1]

Originally Posted by Big Butt

thank you I should have listen to spell check. How are some people getting 10 to 12 mpg with a 400?

They, er, well , extend the truth a bit?

I have a 400 isl pushing 500 hp. I get 8.5 and sometimes better if on flat land.

[Cat320]

With our 400 ISL, we average 8...big tail wind 9, big head wind 7.

[JMonroe]

Originally Posted by Big Butt

... How are some people getting 10 to 12 mpg with a 400?

They're not. The claimed mpg goes up in direct proportion the number of drinks consumed or the amount of time spent around the campfire.

From what I've seen reported, 7 to 9 would be "normal" for that combination. Terrain, weather and driving style are all major factors in your actual results as is the state of maintenance and tune.

[stuhly]

Are you people insinuating that an RVer would be less than truthful about fuel mileage? For shame, for shame.

[YC1]

Originally Posted by stuhly

Are you people insinuating that an RVer would be less than truthful about fuel mileage? For shame, for shame.

I would never insinuate that. But I suspect a lot of us are fisherman!

[powerboatr]

We have the ISC 360
and we are HEAVY at every trip, pulling the truck on the hauler trailer
in the range of 37-39K some trips we are 41k, depends on how many trinkets the grandchild acquires on the trip

i run 63-64 with cruise except in hilly areas
we recently returned from a long over 2600 mile trip to northern wyo back to north east texas
had lots of wind one way
had rain
had HOT days, had weird traffic
averaged out to 7.5 for the entire trip
some days i got 8 + and some days i got 4 or less for some legs
Trip 2603 miles/343.6 gallons = 7.5 mpg that entry is from my data logging excel spreadsheet
this includes many hours of genny usage, (32 to be exact)
its been true since we purchased this puppy in 2009
i plan each trip at 7 mpg and go from there for legs and fuel stops

[ARTWERKE]

You might get 10 mpg. driving west to east across Texas, it's downhill with a tail wind.