8.1 MPG on 37' Gasser

[MetalGator]

We recently purchased a 2018 Miramar 35.3. It has the Ford V10 with the 6 speed transmission. I finally remembered to hit the trip odometer when I fueled on a recent trip. When I fueled again, I manually checked my mileage. On the 200+ mile trip, I got 8.1 MPG while towing our Jeep Wrangler. I was not running the generator and I was driving about 65-67 mph on flat terrain. The engine has just over 3000 miles on it. I was pleasantly surprised at this. I thought I would get 6.5-7mpg. I don't worry about milage but thought this was pretty good. When I used to tow my 30' trailer I would only get about 9.5-10mpg in the truck.

Burch

[gutfelt]

If a person has to resort to worrying about fuel costs and staying in wallmart parking lots etc they really ought not to have a RV

[tropical36]

Coffee Grinder wrote:
We have a 35’ F3 V10 and rarely hit 8 mpg maybe with a tail wind. We drive 65-68 @ 2400 RPM’s. I would love to know how to get to 10 mpg

As already said and indicated, slow down to where it just stays in top gear OD. Saves on other things, as well and sometimes your life, even though, you may never see 10mph.
You're driving a rolling motel there, not a sports car.
Lastly, when you're running low on cash for fuel, stay at a Walmart, which does wonders for managing fuel costs. Buy your fuel and other necessities from them during your stay, for even more savings.

[Mr_Mark1]

Coffee Grinder wrote:
We have a 35’ F3 V10 and rarely hit 8 mpg maybe with a tail wind. We drive 65-68 @ 2400 RPM’s. I would love to know how to get to 10 mpg

Slow that baby down!!! Run 55-60 and see what you average.

MM.

[Coffee_Grinder]

We have a 35’ F3 V10 and rarely hit 8 mpg maybe with a tail wind. We drive 65-68 @ 2400 RPM’s. I would love to know how to get to 10 mpg

[gutfelt]

high weight and low torque = low fuel mileage also the real new ones have like 6-1 gear ratios

[Gjac]

gutfelt wrote:

MrWizard wrote:

gutfelt wrote:

Gjac wrote:
You really need more than one fill up to see what your real MPG will be, but 8.1 MPG is a good start.

flat ground 8.1 towing is great when you hit the west mountain passes it will be 6.1 ;; mileage wont increase as more miles added as some like to think
that's old school mentality

I think it does
But not because of engine break in
It increases because as you become accustomed to driving the RV your driving habits adjust, and that increases efficiency

agreed driver habits can effect fuel mileage as does speed

I think driver habits makes the biggest difference in MPG also. Over the years I installed Thorley Headers, FF muffler,CAI, advanced timing from 4 to 9 degrees BTDC and saw increase in performance but no increase in MPG. I installed an old vacuum gauge I had in my garage and the MPG average increased from 8.5 to 8.7 MPG. Driving at 60 MPH increasing speed when approaching a hill and decreasing throttle as you climb the hill to keep from downshifting all help a little. I know from watching the vacuum gauge when it will down shift and also know better fuel mileage occurs when vacuum is over 10 in of Hg. I still don't no why these newer MH of similar size, 6 speed transmissions and newer engines don't do better than 8 MPG.

[ThomBoles]

We have done a bit over 10K miles since June from Florida up to Ohio then west to Washington, south to San Diego and back through the center of the US. Over that distance I have an average of 6.8 mpg. Not great by any means. We've got the V10 with 5-star but only the 5-speed. I wish we had that one more gear to drop the rpm's at speed. We try to keep the mph in the 65 range as well.

[gutfelt]

MrWizard wrote:

gutfelt wrote:

Gjac wrote:
You really need more than one fill up to see what your real MPG will be, but 8.1 MPG is a good start.

flat ground 8.1 towing is great when you hit the west mountain passes it will be 6.1 ;; mileage wont increase as more miles added as some like to think
that's old school mentality

I think it does
But not because of engine break in
It increases because as you become accustomed to driving the RV your driving habits adjust, and that increases efficiency

agreed driver habits can effect fuel mileage as does speed

[MrWizard]

gutfelt wrote:

Gjac wrote:
You really need more than one fill up to see what your real MPG will be, but 8.1 MPG is a good start.

flat ground 8.1 towing is great when you hit the west mountain passes it will be 6.1 ;; mileage wont increase as more miles added as some like to think
that's old school mentality

I think it does
But not because of engine break in
It increases because as you become accustomed to driving the RV your driving habits adjust, and that increases efficiency

[edm3rd]

mmccray100

"It shows instant Mpg and average mpg, but resets when the engine is shut down."

Actually all that is reset is "Current Average MPG and Instant MPG" which is since last time engine was turned off. The ScanGauge still retains average mpg for today, previous day, and for the tank.

[Matt_Colie]

Burch,

As an many decade automotive engineer and long time RVer, I am going to suggest two things that may be no more valuable than any other free advice.

First, make the habit of writing the mileage on every fuel receipt. Then later, you can roll them into a spreadsheet and get good answers. This will also help if you plan to keep the coach a long time. At some point the engine will need attention, and the jump in fuel rate will convince you.

Second, buy a Scan Gauge. They are a simple install and well worth it and if you use it to watch your driving, you can figure out what you are doing that is not doing you any good.

Matt

[Lwiddis]

75 in a MH towing a Jeep for a personal emergency. Sorry I don’t buy it.

[Mr_Mark1]

Burch,


It will be interesting to see what changes you will have when everything 'seats' in the engine. I kept all of our fuel receipts with our trip mileage and gallons used. It really gives you a feel for your coach's performance.

Safe travels,
MM.

[Jayco-noslide]

I'd say that's good. Would be even better at 60 MPH and with a lighter dinghy. I do better with our 30 footer towing a Chevy Sonic but not much.

[mmccray100]

I've got a '99 Winn 34'with the Ford V-10 and tow a Kia Soul on a dolly. I have problems filling the tank, I guess due to some restriction in the filler tube. I've only been able to actually fill it up on a few occasions. Usually the pump till shut off well before full, so I have to play with it to get as much as possible before I give up. Since I can't reliably fill it, I bought a Scan Gauge. It shows instant Mpg and average mpg, but resets when the engine is shut down. Depending on the terrain, I've seen the instant mpg as low as 1.9, and the average as high as 12-13. My overall average for the 2+ years I've had it is about 7. I've got the 3 speed + overdrive. I would assume the newer 6 speed would get better average.