Fuel Mileage

luvrbus · September 09, 2012, 07:22:07 PM

You beat me to it Jim I wasn't going to give Eric a real bad time but I know how far off the SliverLeaf and Pro/Driver can get the only true measurement monitor is the FloScan used on planes and in the marine world Davenport has one in his Eagle but they are pricey

According to my DD scholar the 12.7 will not get as good of mileage as the 14.L and the DD15 beats both so size is not a problem seems like the more L the better the mileage fwiw

Ed Brenner · September 09, 2012, 07:35:17 PM

Eric will have a second shot at his mileage figures. I am re-powering with exactly the same setup as him. To the letter, he has gotten all the parts for me so far, engine trans , ecm, trans computer same rear end ratio,tires.

If I don't get his mileage, he has aggreed to pay the difference in fuel !!!!

Jury might be out for a while, just started this project, and as Eric says "WHILE WERE AT IT"

Glad this is my only project in the works. ( when I'M done the " T " bucket and trike will be in a trailer behind ) and me and the wife are going to take on the west coast mountains!!
ED

Ericbsc · September 10, 2012, 05:45:45 AM

I have checked the mpg manually also. It is pretty hard to do because with a 150 gal. capicity, it is always possible to shove in a few extra gallons!!LOL This makes i look better. I was running the generator a few times also which must be accounted for. I am sure Jim knows more about the silverleaf and its accuracy than anyone here. If it is wrong I would appreciate it if he WOULD NOT TELLL ME!!! If I don't know it I am still getting 9 mpg!!LOL

muldoonman · September 10, 2012, 06:18:47 AM

Just got back yesterday from the beach (Surfside Tx.) Averaged 5.4 running 65 on cruise and pulling ford Edge. Silver 8v92 TA with 5 speed auto. Weight slip says 42000 lbs. Haven't weighed it since i've owned it. need to, that sounds heavy. 350 mile trip.

rusty · September 10, 2012, 06:47:59 AM

You 60 seires guys are raising the bar. When I started my 15 I told someone I wanted to get the mileage over 10 and I heard you can't get that kind of milage with a 45 footer. Well thats all it took to tell me I can't do something. The following is a list of things I have done to my Eagle to help get over 10 MPG's. 1) remove the dropbox and replace with a T-Drive rearend. 2) used a manual trnsmission Eaton 10 speed autoshift. 3) Tires with a lower rolling resentence, 4 super singles in the rear. 4) a 14L 60 seires turned up a little. 5) a two speed fan 6) Remove all the junk from the roof ( I will still have stuff on the roof just hide it). 7) make the body as smooth as possible. 7) proper gearing ( with a T-Drive that will not be a problem. The thing that is not going to help is wieght, My Dad always told me I build things to strong. He is correct, But I have a few tricks to reduce the wieght from here on.

Wayne

luvrbus · September 10, 2012, 06:55:27 AM

Yep Wayne I told you that lol even with a EGR 14L I still think you will get close but you still have to account for the EGR fuel

rv_safetyman · September 10, 2012, 07:20:05 AM

Eric, look at it this way: The DDEC ECM fuel usage reporting error may be in favor a even higher mileage

I wanted to make sure that folks understand that the fuel usage data is accurately recorded/reported by SilverLeaf, ProDriver, etc. The error (if any) occurs withing the DDEC ECM. As noted, it is a calculated value based on injector calibration and pulse width timing. SilverLeaf provides a calibration adjustment feature to account for a ECM reporting error if one exists.

Eric, since you have verified the mileage via the hand calculation method, I will believe your numbers

I am amazed at the work Ken is doing to "modify" the data tables in his ECM. He and I talk about it and it just boggles my mind. I think he will get a handle on it and get some great results.

Jim

muldoonman · September 10, 2012, 07:35:07 AM

Are the electronic fuel mileage calculators accurate? Hand method to me is the only way to get it down. On a couple hundred gallons if you fill and miss one or two it gonna make that much difference. We didn't buy these big puppies for fuel mileage anywho! My Dad once told me to never trust someone that tells you there incredible fuel mileage. I'm happy as a peach with 5 mpg. Those ragheads overseas need to make a living too! NOT!

luvrbus · September 10, 2012, 07:48:37 AM

You can do anything you chose but a series 60 engine making the same hp, same torque at the same rpm they are going to use the same amount of fuel the 14L will do the same hp,same torque with less fuel because of the size is my understanding without the EGR

My friend at Arrow has 300 buses with Volvo,Detroit and Cummins engines the best mileage comes from his Setras with the DD13 and the T10 Allison transmission they are 9 +mpg the rest are in the low 8's fwiw he racks up more miles in a month than most converted coaches do in a year and keeps a very close watch on fuel

His are all modern day coaches design for less drag not the boxes of the past

Ericbsc · September 10, 2012, 08:10:46 AM

I think with the 10-13 speed autoshift setup like Ken and Wayne are doing it will get even better. I still the trick is to keep the series 60 between 1300 and 1600 at average highway speeds. I am sure it would pull just as good a 1100 rpms according to the tourque chart. I can't do that as the 4000 series allison needs around 1250 rpms to oil properly at highway speeds. Shouldn't be a problem with the autoshift.

luvrbus · September 10, 2012, 08:18:32 AM

Eric the T10 is a 10 speed transmission Allison and a great one at that a lot better that auto shifts of the past it will just be a while before you can find one used I drove both the autoshift and T10 the auto shift is not in the same league as the T10 lol

rusty · September 10, 2012, 08:22:57 AM

I know some say the automatic transmissions in lockup or overdrive do not use any more energy ( fuel ) than the manual Transmissions. The 740 in my 05 while in lockup in 4th gear still puts out heat and heat is only produced by fuel. Thus I will go with an Eaton Autoshift 10 speed.

Wayne

robertglines1 · September 10, 2012, 05:47:21 PM

I'm listening; Just hoping for around 8. Still shooting for under 40 thousand rolling. Not quiet as scientific as some of you guys ,but I do learn. Bob

Hard Headed Ken · September 10, 2012, 06:01:21 PM

Quote from: robertglines1 on September 10, 2012, 05:47:21 PM
I'm listening; Just hoping for around 8. Still shooting for under 40 thousand rolling. Not quiet as scientific as some of you guys ,but I do learn. Bob

Bob,
Have you run the numbers for your gearing setup? I think with a 4.56 diff and a .74 top gear you going to be kinda high in the RPM range for the best fuel mileage, plus your bottom 3 gears or so will not be very useful.

Ken

robertglines1 · September 10, 2012, 06:30:39 PM

Bottom 3 are about useless . maybe pull stumps. The 4:56 is the highest of the two I had access too. The other was 4:88. So was a math thing. Should climb hills great! I'm probably a 70 mph driver most of the time on the interstate. The 4:56 is the one that actually came out of the XLE origianally and found it's way back home. Fairly sure I got the numbers correct. At the time I reasoned The entertainer coaches were higher geared and was the correct choice. This was before I really got into thinking about the numbers. Might make some future adjustments as $ allow. What gears do you suggest that will fit my case? I need to look and see again if I have A or B Eaton. I have forgotten. Bob