Fuel Mileage

[Mex-Busnut]

Somebody on here a while back claimed he was getting 13 MPG on his bus: 6 mpg going, and 7 mpg coming back!

[Hard Headed Ken]

Brown will pull your leg Ken lol,he may get 10 Hal gets over 9 mpg with a 625 hp 14L series 60 with larger and heavier Eagle than Eric and Hal won't pull your leg

Eric's my friend and he knows I'm kidding around with him. I just want everyone else to know.

My gearing is almost the same as Eric's, I'm 1400 RPM at 70 MPH. It seems you should be able to get 10 MPG with that gearing. I believe Eric, I got to get mine there. 

Uncle Ned adds his city and highway together for his total MPG

Ken

[robertglines1]

If mine turns out over 7.5 I'll be happy  8+ very   and everything over that gravy. 60 series 10sp auto shift  4:56 gears 315 80R 22.5 tires. 430hp-470hpcruise   Bob

[Ericbsc]

Clifford, you have to keep in mind that Ken is running a 14l, not a 12.7. I've been called a lot of things!!LOL I always say I don't care what you call me as long as you call me at quiting time and payday!! I know I can get over 10 mpg, because like Ken, I have checked it manually. It is pretty hard to check manually. You can vary the full tank by 3-5 gal. just by stuffing a little more in the tank. I'm not going to say that it is not possible to get 12-13 mpg with a 40k rig, but I would think that you would have to check it going down hill, in netural, and not over 35 mph.!! Matter of fact I may try it!!! Bett you I will get over 15 mpg Clifford!

[luvrbus]

I don't doubt you Brown running the flat lands along the coast but the 14L has always gotten better fuel mileage than the 12.7  so I don't know why Ken is not as good as you but I bet he gets there lol he may need to add a drop box what you think

We will wait till Wayne gets his Eagle and 14L on the road he tells me he going to be 10+ also I do know the 14L will average about a mpg better in a H-45 than the 12.7

Let's not forget Boomer with his 45 ft Eagle and Cummins he is around 9 to 10 mpg he has been for years, really you are the only one I know that get that mileage with the setup so you did something right most Eagles are in the 7 to 8 mpg


good luck

[wayne]

I read these MPG threads every time they come up and everyone has different theories on how this works. I have tried a lot of them over the years and my tried experience is always the same.  My heavy trucks loaded at 168,000 lbs running  Cats which I think are the worst for fuel mileage get 4.8mpg at 69mph. If I slow them down to 55mph on cruise it will jump up to 6mpg. My light trucks loaded at 80,000lbs running Cummins (which I have had the best luck with for fuel mileage) get 7.4 at 70 mph. If I slow them down to 55mph on cruise they jump up to 8.5mpg.

I had this thread on my mind this morning when I drove to pick up my daughter from soccer camp. I drove 185 miles round trip all highway with my 09 Ford F150 (5.4 gas engine). The best the truck has ever done for me on the trip computer is 17.2mpg but I drive between 70-80 probably average 75mph. Today I set the cruise at 55 mph (felt like I was sitting still) but for the first time ever the trip computer reached 18mpg. I dont know where it would end up on a longer trip.

Reality is 55mph seems to be the magic number. The new technology has enabled us to get way better fuel mileage even at higher speeds but does not change the wind drag coefficient, atmospheric aerodynamics, and friction. On the days I want to cruise at 70mph I do, but the days I want to save fuel and count the gallons I just slow down a little and cruise.   I have no idea what fuel mileage my bus is going to get, 1994 8V92TA with a world 6spd. I plan on finding out toward the end of this year when I think it will be finished but I don't have any experience with these 2 strokes so this will be a learning curve for me

[luvrbus]

Wayne, the DDEC 8v92 with a World transmission will do fine you will be in the 7 to 8 mph range at least the ones I been around do you don't see that setup often but when you do they work as good as a 60 series

[wayne]

anywhere around that would make my day, 8 would be fantastic

[luvrbus]

Don Fairchild did some tweaking on his 8v92 with that setup he gets around 9 towing a 1 ton Chev dually a heavy sucker

good luck

[mikelutestanski]

HELLO;   Just finished a 3500 mile trip with the bus.  Ran 60 most of the time except one stretch from evansville to chattanooga  (70 + except thru cities).  We are running  a mechanical L10 @310hp with a B400R 6 speed computer tranny with a 4.625 rear end.. Mci 7 bus is at 36000 plus towing a saturn 
    Fuel mileage for one set of mileage was 3681 miles / 453.3 for 8.12 mpg.   Another set all during the trip was 2819/ 360 for 7.83mpg...  Any genny time is included.. We spent 12 days at non camping spots (flying J NS Wally world).
     Left florida went to pittsburgh then west thru michigan, ohio, indiana, back to NC  to florida.  Some eastern mountain driving in west Virginia including fancy gap.  i ran in 5th most of the time.
    We tried the slower version of a vacation driving 200 or so miles per day on state roads @ 60   except for the IN to TN run.
   THe bus ran well.  Had to replace a new sams battery obtained before we left.  It dropped to 10.5 volts soon after stopping each day. Replaced it in muskegan michigan sams. 
   Changed a starter At Bob Glines in evansville but it was acting up before i left.  Turned out to be a bad bushing. I thought it was the battery but not so.
     Anyway a good trip after all.  We were going to ALaska but medical reasons cut that off and ended up doing a midwest tour.   
    Attended the back to the bricks rally in Clio michigan.  had a great time; met some fine bus people . Thanks to Ed Roelle and company for a fine rally.
   Many thanks to Bob Glines and Tom Mason ( white eagle)  to allow us to stay and visit.  We did the museum tours and the local sights .    USS silversides sub and LST at muskegon MI.   Also another LST at evansville IN
       Regards and happy bussin   mike

[lvmci]

Wayne, does the 09 5.4 ltr ford still spit out spark plugs, like my 97 F250 5.4 does, lvmci...

[wayne]

Mine does'nt spit them out but they will break when attempting to remove them. I did break one last month because a coil went bad and the book suggests replacing the plug with coil.  Ford even makes a tool for the spark plug removal with instructions on how to break them off properly. I heard getting the plugs changed at the dealer is a $800 bill.

[Ericbsc]

Alright Clifford!! you have forced my hand!!LOL This is a pic of my silverleaf as of ten minutes ago. The figures I quoted earlier are individual trip sets. This shows the total miles, avg speed . This includes a hundred trips across town and around the block during the debug process.  Three trips are included in this. Charleston, SC, Chatanooga, TN, and Nasheville, TN. The 10 mpg trip was the only one which I did not pull a trailer. It is 20' x 8.5' . We carry two harley full size touring bikes in it. During the trips taken I rest my case and leave my fate to the jury!!

[Ericbsc]

I almost forgot: The Charleston trip is probably the only time I have kept it under 65mph. Most of the time I run 65-70. The bus weighs in at 41,700 lbs. The trailer is app. 6k lbs, and the bikes weigh about 1k each. When I had the 8v-71 I kept the pedal to the metal to stay above 60. Worst was 5.1 mpg, and best was 6.5.

[rv_safetyman]

Eric, not doubting your mileage, but I have to point out the SillverLeaf can give false fuel data.  In truth, it is not SilverLeaf as such, but the information given to the VMSpc.

I have found that the mileage numbers tend to be pretty good if the DDEC ECM is set correctly for the tire size and rear end ratio.  However, the fuel used is a complicated calculation based on injector calibration and pulse width for each cylinder firing.  If you think of that complexity, it is mind boggling.  For example, one set of the same part number injectors is slightly different from the next.  In a perfect world, the ECM would be set for a new set of injectors.  Next, there are three injectors firing per revolution and if the pulse width is off ever so slightly, that affects what the engine thinks it has used in fuel.

To give you a feeling, I set an odometer just for fuel.  Each time I fuel up, I zero the gauge.  My generator and AquaHot come off a separate tank.  For my first engine, when I pulled in to fuel, the fuel used and fuel filled agreed almost every time to within a gallon or two and it bounce on each side of the VMSpc reading.  My "new" engine almost always seems to read low on fuel usage on the VMSpc.  On the SilverLeaf, you can program a correction, but I have not done that.  Over the past 160 gallons, it looks like I could be off by 10 gallons (guess - have not had a chance to check). 

I talked to Ken today when I was on the road.  I gave him a hard time  .  My trip odometer (about 160 miles) read over 10MPG and my fuel odometer (about 30 miles) read 12.6.  I know that neither are correct.  I have slowed down a bit on the past few trips (about 65MPH vs 68MPH) and am pulling a PT Cruiser on a dolly (as opposed to my 9K service truck) and the VMSpc shows a bit over 9MPG.  While I have not spent a lot of time going over my fuel records, I suspect the real number is closer to 8.5 or a bit lower.

If your fuel used agrees with fuel filled, then your are indeed getting great mileage.

Jim