Fuel Economy of your Motorhome

[Musikboy]

This was my maiden voyage in our new Thor Tuscany 40EX this past week. We drove 1000 miles back from Knoxville, TN over the course of 3 days. We were in no rush, we did not pull a toad, we had not used the Gen underway and we didn't restrict our use of dash air, we used it as we needed.

We started with a full tank and then topped off twice. Over the course of 1050 miles, we averaged 9.49 miles per gallon. I was thinking this was about average or even a little low. I had heard that we should get about 10-12 mpg with no toad.

We traveled at 62 mph most of the way, on cruise control a lot of the time. The Cummins ISB 360 hp engine performed well, we sailed up inclines without a strain or slowdown. We have an "exhaust brake" switch on the dash which I used frequently on the down slopes and found it to handle easily anything I encountered.

Over the entire trip we used about 1/4 tank if DEF. I am ordering more from Amazon so I carry a spare. Seems like a pain to fill up at a truck stop.

My question is; What is your mileage when you travel? Do you tow? Do you use your Gen underway? How fast do you go?

Here's the BIG question... What can we do to improve mileage? Do these fuel enhancers work? any other voodoo we can perform to boost economy? What about those $600 "chips" or programs, do they work or do they hurt the engine/transmission? Void warranty? Waste money?

All newbie questions, I realize but just wanted to get a benchmark and see what everyone else is doing.

Thanks!
Mitch

[PDR John]

We'll get anywhere from 5.9 as a low to 8.5 as a high, with over all average at 7.5.

I'm shoving a 44,000 lbs brick down the road at 62 mph, nothing is going to be efficient with that weight and aerodynamics.

I run the genny when it's hot and I want to run the roof ACs. I run the Oasis boiler when it's supper cold and I want more heat.

[jlr44]

Sounds like your are on the right track. For me I went and bought two 5 gallon gas cans and went to a local station and filled them with DEF for $2.13 per gallon. Good luck on your travels

[Musikboy]

Originally Posted by jlr44

Sounds like your are on the right track. For me I went and bought two 5 gallon gas cans and went to a local station and filled them with DEF for $2.13 per gallon. Good luck on your travels

I have to look further, 3 stations so far that pump Diesel don't pump DEF. But that's a great suggestion!

[hawgguy]

I have the 350 engine with a same sized coach, no DEF but I do have the DPF and EGR. You are doing great. 10-12 mpg seems a bit optimistic. I tend to drive a little faster, with the genny on to run the roof airs and with a toad. (33-34,000 lbs at the scales). It seems that I usually have a headwind, weather going east-west or visa-versa (just my luck). I usually see 7-7.5 mpg, maybe more if my wife is driving. I have heard that the engines with DEF are a little more efficient.

[mel s]

Originally Posted by Musikboy

This was my maiden voyage in our new Thor Tuscany 40EX this past week. We drove 1000 miles back from Knoxville, TN over the course of 3 days. We were in no rush, we did not pull a toad, we had not used the Gen underway and we didn't restrict our use of dash air, we used it as we needed.

We started with a full tank and then topped off twice. Over the course of 1050 miles, we averaged 9.49 miles per gallon. I was thinking this was about average or even a little low. I had heard that we should get about 10-12 mpg with no toad.
My question is; What is your mileage when you travel?
All newbie questions, I realize but just wanted to get a benchmark and see what everyone else is doing.
Thanks!
Mitch

Mitch
My coach has averaged 8.5 MPG over the last 105k miles, (towing or not).
That's $37,000+ worth of diesel...(BTW, at today's diesel prices that would be more than $50,000)!
If I could get 9.49 MPG I would be extremely happy.

Mel
35', '96 Safari, (3126 Cat), 132k miles

[NorthernDriv]

DP.......I believe that stands for the Mileage....Darn Poor...!

[Green D]

My first DP was a 275HP 36ft rig it avg 10.5 towing, so i dont think you will see those numbers.
My current MH avg 7.5 towing have seen 8+ on good days but avg 7.5 450HP 43ft

Just enjoy it!
Eric

[terry735001]

i dont know to be happy or sad for me


when i installed the GM350 gas motor in my DP just to get the RV home i was getting on a flat roads 7.5 to 8 MPG and did this for 1200 miles with a rv 33-34,000 lbs as well

[Skip426]

A whole bunch of questions and answers possible you'll get a ton of replies.
Maiden voyage, new coach , the big diesels don't achieve their best power and mileage till they're broken in, @ 25>30k miles.
The chips will void many warranties, engine/ transmission, and even if they do provide the mileage increases they claim could take many YEARS , depending on how much you drive, to provide a financial benefit.
Cat, used to have a pdf. file on their web page when they were still producing on highway engines. " Understanding Coach/RV Performance " should be required reading for every coach owner no matter what engine they have. I have it in print copy , and if I can locate a link I'll post it for you.
Top three ; in order; things that effect fuel mileage, Driver, Route & Speed.

[Skip426]

Found it. Please take the time to read this.

[Scarab0088]

The #1 way to increase MPG is to reduce the speed. While 62 is admirable, going 55 might increase MPG by a measurable amount. Over time you may find your RV's drive-line set-up has a sweet spot for MPG on flat terrain...this varies rig to rig.

The #2 way to increase MPG is reduce weight. The OP was probably at the lightest weight that the RV will ever be, being new. So try to refrain from filling every bin with stuff you might not need. Even to fill the fresh water tank or not can impact the MPG.

The #3 way to increase MPG is speed control on inclines. Going uphill could be done at a lower speed to save fuel...then run down the backside. Most believe the cruise control is your friend, but that is not true when driving in hills or mountains.

Engine chips work, but might void a warrantee. Airflow devices might have some impact, but can be expensive.

Best luck and congrats on the new Coach

[ohhwell]

I think the only problem is with whoever told you you would get 11-12 MPG in a 40' DP.

[ohhwell]

Originally Posted by terry735001

i dont know to be happy or sad for me


when i installed the GM350 gas motor in my DP just to get the RV home i was getting on a flat roads 7.5 to 8 MPG and did this for 1200 miles with a rv 33-34,000 lbs as well

Now that is interesting beyond just the MPG. Do you have a write-up on that process anywhere?