Last weeks MPG😂

[Rikadoo]

So last week i did myself a favor, i took myself on a motorhome adventure, i left the bay area heading to Carson city to visit my sis. Stopping in Sacramento to top off my tank before i hit the summit. This route i take which uses I-80 is pretty much a milk run for me, having lived in California most my adult life heading to Nevada to visit family was something i did often using the same route. So when im driving my car im not so worried with MPG as i am with time. However driving my DP its just the opposite, after visiting sis i had planned on extending my week by heading to Klamith falls before i head home. Again filling the tank i checked my milage, same ole story 6.3 MPG, that seems to be the norm, oh well off i go. So taking the route to my new destination i noticed there was alot of straight stretches, my mind went to “oh this should help with my MPG”. Sure enough having concluded my visit i stopped to fuel up. It went to 7.3mpg, i was soooo pleased with myself, having related my driving habits to the different route, flat plains vs mountain driving👍 What a great feeling😎! 
So now i start the trip home Sr139 to I-5 all the while hoping i might be able to eek out some type of perhaps a couple more tenths of fuel milage.
Due to a lack of fuel up spots in my town i decided to stop about 50 miles from home to top off the tank, plus i was anxious to pre view my progress with the fuel milage… Now i knew going over this pass which i had never driven before seem to have more downhill than up however i was kind of oblivious to that fact in part to being “more aleart” cause not knowing the terrain i was very cautious and trying to get some better mpg #’s than the last. OMG😳! 10.7 MPG🙀🙀🙀 i thought i was gonna go hug the front of my RV right there in front of God an all those truckers😂

So you all know MPG is such a elusive beast we all look for, AND yes i know very well that that mountain i just came off was mostly all downhill and in no way reflects a realistic number, but like fishing stories this is one heck of a whopper i will tell around the campfire for a while!!!

I hope all your adventures are as fun and exciting when your getting to use your rig👍👍👍

[Guest Ray Davis]

Great story Rik, what is the saying, never let the facts get in the way!!

[DavidL]

Couple of thoughts, 6.X MPG sounds low. 10.X sounds really high.

How are you measuring MPG?  How many gallons go in the tank (use the fuel stations measurement) divided by how many miles traveled.  Since it's very hard to consistently get the tank to the same degree of "fullness", there is always some inconsistencies.  Several tank fills will round off the issues to get a good approximate.  But then you won't know which driving style made any difference.  I assume the engine controller measures MPG...that is better to track driving technique as it measures near real time.  Compare ECU mileage compared to long haul fuel station measurement to know how accurate the ECU is compared to actual usage.

If the vehicle is running well, and I drive to flow with the traffic, and am not leaking fuel, the mileage is what it is.  The bigger factor is the cost / gallon which we have no control over, so enjoy the trip!

Edited October 24, 2022 by DavidL

[Cubflyer]

18 minutes ago, DavidL said:

How many gallons go in the tank (use the fuel stations measurement) divided by how many miles traveled.  Since it's very hard to consistently get the tank to the same degree of "fullness", there is always some inconsistencies

Rik,

I have found, that the side to side angle of the coach at the fueling station has a larger effect on MPG than hills or things being towed...   I've seen swings like yours running flat lands and the same speeds.  I do a mileage-fuel pumped calculation every fill up and have never gotten two the same in a row... same day, same terrain.

But I LOVED your story!!

Ken

46 minutes ago, Rikadoo said:

MPG is such a elusive beast

 

[96 EVO]

According to my Alladin, my coach has averaged 7.7mpg over it's life.

Edited October 24, 2022 by 96 EVO

[Ivan K]

My ECM was reporting 8.4 MPG average over its lifetime until I realized that rear end ratio was set wrong. Just as wrong tire size input, all make a difference.

[96 EVO]

On our southern migration trips I get 8.0-8.1mpg, which consists of about 4/10ths mountain driving, 6/10ths flatland.

I bought the coach with 30,000mi on it, and it was at 7.6mpg average.

[CLIFF918]

This year I averaged 8.6 round trip Fl to Vt and back towing my 2020 Ranger. 
it is not the mpg but the cost! 
3600 miles/8.6 is about 420 gallons of diesel X $5.59 average  equals roughly 

$2300.00 round trip

if prices don’t come down I doubt I will do that again next year . Maybe some short trips in Fl

 

[TomV48]

Our 2005 HR Ambassador lacks a bunch of fancy electronics so I added a Scan Gauge and set the display to show me Engine Temp, RPM as well as Current MPG next to total MPG for the trip, which turns out to mean, since last time I shut the engine down.   That gauge helps my normally heavy foot stay under some level or control, BUT I NEVER BELIEVE the electronics.   The one in my CRV Toad, lies by about a half a mile per gallon and the one in the 2004 Ford Diesel Truck lies by a full MPG.   SO I just DO THAT MATH  miles/gallons.   I do my "Level Best" to use a fuel bay that looks most level as I pull up.   I take my time and let the foam settle a couple of times squeeze the nozzle lightly until I can see fuel level visually.   I usually fuel after about 500 miles.  All that effort and driving with the lightest touch on the fuel peddle and at About 30,000# pulling another 3900# in and of the CRV , with our Cummins 8.3L,, I have nailed it down on Interstate highways to 8.2 mpg plus or minus .2.  Then I surprise myself on the occasional trip with no Mountain passes and No Continental Divide with an occasional tank at nearly 10 mpg.  

Edited October 24, 2022 by TomV48

[cbr046]

Sometimes I get a very good MPG after filling, like 9.5 - 10.0.  I expect the next fillup to average out the good MPG, but more often than not the next fillup is average.  I have no idea where the good MPG's come from.  I try to average 65 (except for uphills), but 70 isn't unusual.  I also tow a cargo trailer. 

My drives are generally round trip between fillups, or even multiple trips.  No downhill mountain drives I didn't go up first.  Mostly rolling hills. 

- bob

 

[Steven P]

Just to add to this discussion.  Ya gotta take into account if your generator has been running or not and factor that in. My Aladdin Jr says I get about 7.8mpg and I've found that to be the case when I've driven a while w no genny running.  But in south AL, it's hot, so it's rare I'm not running my genny.  In other words, fuel in gal at the pump divided by miles driven is not accurate when the genny is running.  But yes, the genny doesn't use tons of fuel, so it can still be close.  

[jacwjames]

When we first bought the coach I wanted to monitor fuel consumption, our first long trip was to Alaska.  I kept a log of all the expenses including gallon consumed and cost.  When we stopped I usually filled up unless we were in a high cost area at which point I pump enough fuel to get to another location plus a buffer.  I found that calculating fuel mpg between fill ups was all over the place which might have been due to road conditions, speed, wind, and very little generator use.  We did not pull a toad.  But over the long haul we ended up averaging 8.3 mpg over the +14K mile trip.  I was pleased as this was better then we averaged in our 31' Class C. 

We now pull a toad pretty much everywhere and I use a Silverleaf to provide mpg, we average about 7.3 mpg. 

 

[cbr046]

1 hour ago, Steven P said:

But yes, the genny doesn't use tons of fuel, so it can still be close.  

I figure ~0.5 gal / hr for my genny.  I think that's at 1/2 load, but I forget.  There's lots of other factors, like if the AC is running 100%, other loads (hot water?) on the genny, etc.

At 60 mph an added 0.5 gal / hr will move 8.5 mpg back to 7.93 . . . . or just subtract 1/2 mpg.   It's a WAG but still gets you in the park.

- bob

[Chuck B 2004 Windsor]

For us, half the fun of going anywhere was the drive getting there.  Except for passing, going downhill, etc, I never went over the speed limit or 60 mph.  I tried to plan my day drive by not going over 50 miles in distance on must days.  Every where we went it was a 2 timer, the first and last time we went there or added to our come back list.  Every road we traveled was different so I never worried about MPG.  When the tank reached 1/2 empty, I filled it back up.  Therefore I was seldom stressed out at the end of the day driving to reach a pre planned destination.  AND I was able to enjoy the scenery while driving.  

Fast forward to today.  When we go to Hattiesburg, I abide by the speed limit.  Many times when I was first at a traffic light, I am Never the first vehicle off the starting line.  Saved a lot of accidents of getting hit from a vehicle running a yellow or red light.  Many times the vehicle next to me pressed the pedal to the metal when the light turned green only for me catching up with them at the next traffic light.  Stressful driving for them, relaxed driving for me.  

I am 81 years old.  The last traffic ticket of wreck I had was when I was 28 years old.  God willing I will stay that way.  

[Chuck B 2004 Windsor]

OOOPPPS, 300 miles in distance on most days.  Sorry

[TomV48]

300 mpd sounds like me on a good day, but only push that far if on Interstate.   With near hourly "rest stops" between her bladder and mine, that makes for 7 hrs on the road.  We are lazy, slow starters in the morning and DW prefers we be parked by 4:30 pm but absolutely before sunset.

[W7BE_Bob]

The only reliable way to determine MPG is to average it over multiple fill ups. 5 might be OK and probably a minimum. Mine is averaged over years and for any given fillup I see wide variations of MPG. 

My average is 7.9 MPG. Single tank variations from 5.0 to 11.0, 5 tank variations from 6.7 to 10.8.  The variations are due to the shallow cross tank design, variations in driving, not to mention hills, etc. 

For reference: ISL 400, 38,000 lb MH, 5,000 lb Jeep.

But we all know that anyone braging about MPG is lying and sure include me!

[Frank McElroy]

2 hours ago, W7BE_Bob said:

The only reliable way to determine MPG is to average it over multiple fill ups. 5 might be OK and probably a minimum. Mine is averaged over years and for any given fillup I see wide variations of MPG. 

My average is 7.9 MPG. Single tank variations from 5.0 to 11.0, 5 tank variations from 6.7 to 10.8.  The variations are due to the shallow cross tank design, variations in driving, not to mention hills, etc. 

For reference: ISL 400, 38,000 lb MH, 5,000 lb Jeep.

But we all know that anyone braging about MPG is lying and sure include me!

Bob, after 68,000 miles mine is also 7.9 MPG.  I keep a fuel log and the ECM data from the ISL on SilverLeaf matches my overall fuel log once correcting for generator and aquahot use.  Individual trips can vary as it has in the screen shot below.

 

[Rich Cutler]

My old '98 Holiday Rambler, 38' got 10mpg sometimes 11.  Moved up to our 41' Windsor.   With the added weight, 36000lb, it rides like it is not scared of trucks passing and tows the TOAD, full size Traverse, with ease.  We run around 65mph or 63, and run the AC, dash with the overhead ACs.  Have Residential RF18 and Bosh washer and dryer in the rear, so we are no light.  Constant 8MPG regardless.   Generator pulls 1 gal per hr in that 8MPG.  That is how I figure my fuel consumption on the road as I do not trust the gage, especially when it is at 50% or lower.  When I fill up, I can guess pretty much to the gal how much it will take.  I just need to remember to reset the odometer trip meter. learned not to trust the gage after a couple of times loosing the generator fuel feed due to low level.

[pulsarjab]

Out here in the plains of central USA, wind has a big impact on MPG. We have seen 12 MPG traveling through Oklahoma with a 20 MPH tail wind. Head winds have reduced things to 6, and on coming trucks really rocked the boat. Side winds also reduce MPG, probably because with all the weaving and bouncing around we are increasing the straight line distance traveled. Very few travel days without wind.

[amphi_sc]

Using very simple math I tell people that ask me as I'm filling up that on a long trip I'll average 25 mpg.  They look stunned in disbelief. I'll go on and explain "yeah, I drive a hybrid, sometimes I'll average a little more, sometimes a little less".  Really they say, that's just amazing!  I conclude with "yeah, the coach gets 6, to the hybrid toad gets 44 so that averages out to 25....😁. Often more if I'm camped for a while using the car a lot to sightsee."