BCM Community

Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Len Silva on June 18, 2007, 10:57:13 AM

Title: Fuel economy (again)
Post by: Len Silva on June 18, 2007, 10:57:13 AM
I know, I know, If you have to ask, you can't afford it!
None the less, fuel economy is an issue for me.
I have done a seat of the pants study of various coaches, gathering info from several sources over the years.

The overall mileage champ seems to be the 6-71 Crowns at 11-12 MPG. Unfortunately, they are very rare on the right coast.
Next the 4104/4106 at 10-11
I don't know if the MCI 5-X comes in at the same economy as the GM 41's.

In the 40 footers, I would guess that the two axle GM's are tops.

Next is the Eagle which some folks claim 10 MPG

Then the tag axle MCI's and Prevost at 6-7.

A friend who worked as an engineer at Eagle, told me that they actually did wind tunnel tests in the early 70's.  He said that the Eagles have a very slight taper in the last 10 feet or so and that was the result of their studies and accounts for the high mileage.

I'm looking for any info to add to my data and to collect info on mileage from you guys.

Make, model, engine/trans, driving habits etc.

When fuel was a buck a gallon, it wasn't that big a deal.  At three bucks, difference between best and worst on a 3000 mile trip could approch $7-800.00, not an insignificant amount to me.

Len
Title: Re: Fuel economy (again)
Post by: belfert on June 18, 2007, 01:19:57 PM
Choosing a bus for fuel economy is best done when the shell is purchased.  Unless you travel extensively, you likely will never recover the cost of changing shells strictly for MPG.  It would take a lot of trips saving $700 to buy another shell unless you get one realy cheap and don't spend much converting it.

I did purchase my shell for economy, but I may have been better off spending half as much on an older MCI.  I'd probably be $10,000 ahead which would buy a lot of fuel at 5 or 6 MPG instead of 8 or 9 MPG I get now.

People keep buying new efficient vehicles specifically to save on gas, but they are often spending more on the new vehicle than gas for the old car.  It certainly makes sense to get a fuel efficient car if you planned to replace your vehicle anyhow.
Title: Re: Fuel economy (again)
Post by: prevost82 on June 18, 2007, 02:14:50 PM
I doubt that anyone is getting 10 MPG with 2 stroke Detroit in a 40 ft shell without a 5 tail wind. When I was in Mexico last year I headed back to the border with a 35 ft MCI 5 with a new 6V92TA DDEC/ B500 tranny and I'm running a 8V92TA Mech. / 6 speed standard, we were running around 55 to 60 MPH on flat ground and at the end of each day we would fill up. We were shocked when I was only burning 15 to 20 bucks more on a 400 mile day.

I think speed and terrain make the biggest difference, not the shell. And the guys with the small engines getting 10 to 11 would think they were standing still on some of the long grades there on the west coast ... that's where I burn the most fuel ... but I also not going up that grade for a day and a half. :-)
Ron
Title: Re: Fuel economy (again)
Post by: lostagain on June 18, 2007, 04:43:50 PM
1957 Courier 96, 35 foot, 23000 lbs, 4-71 DD, 5 speed Spicer, my foot to the floor the whole time, 60 mph max, 15 Cdn mpg ( 13 US).
This year is turboed, noticebly more power  ;D, right foot still to the floor, but haven't done a long trip yet to see about milage... I'll let you know for better or worse. 
Title: Re: Fuel economy (again)
Post by: prevost82 on June 18, 2007, 05:21:38 PM
JC ... I'm just a couple of hills away from you in Merritt. It's no wonder your right foot is nailed to the floor, with a 4-71 in the Rockys ^^^ ;D ;)
Title: Re: Fuel economy (again)
Post by: Stan on June 18, 2007, 05:30:07 PM
Until Grayline bought Brewster's. all the sight seeing buses in Banff and Jasper National Parks were Couriers with a 4-71. On the grade going North from the Icefields, I moved over to let a new Brewster MC-9 go by and he got beside me but couldn't pass my 4-71 (free breathing with N-70s).
Title: Re: Fuel economy (again)
Post by: NJT 5573 on June 18, 2007, 07:02:38 PM
Mikes 102 C3 in this months magazine sure looks good to me. Series 50, 1991, $26,000, WOW
Title: Re: Fuel economy (again)
Post by: lostagain on June 18, 2007, 07:11:04 PM
My Courier 96 is an old Brewster bus (no 9), that I used to drive in the seventies. We had 6 or 8 of them then. They got sold in '77. I love mine mostly because of the nostalgia factor 8). It is a great classic bus if you remember them. Just an ugly old thing if you don't :'(
Title: Re: Fuel economy (again)
Post by: TomC on June 18, 2007, 11:06:09 PM
NJT- IMHO- that 102C3 with the Series 50 is THEE perfect setup for a conversion.  Most likely 10mpg with the same power as a 6V-92TA.  I almost wish I was starting on a new bus-I would have bought it by now.  I think you'll see the recent 40ft'rs coming up for sale for relatively cheap since everyone in the commercial bus business wants 45ft'rs.  Good Luck, TomC
Title: Re: Fuel economy (again)
Post by: buswarrior on June 19, 2007, 09:06:40 AM
Hello

Trouble with fuel mileage calculations is the validity of the data.

How full was the tank before?

How accurate is the odometer?

How accurate is the fuel pump?

How much drive to how much idle?

Generator, Aquahot, Webasto, Espar, etc consumption?

The odometer is a little devil for the math, if it is reading wrong.

Appearances in my MC8 are: 6 USmpg, 8V71/HT740 70 mph interstate blast Toronto-Arcadia return

happy coaching!
buswarrior
Title: Re: Fuel economy (again)
Post by: scottwms on June 19, 2007, 11:12:42 AM
My 4103 conversion got 11 cruising down hwy 99 from Ripon Flying J to Bakersfield Flying J. I have the 6-71 and spicer.
Title: Re: Fuel economy (again)
Post by: bobofthenorth on June 19, 2007, 01:28:22 PM
BW hit it on the head.  Single fill MPG is meaningless.  Unless you keep multiple tank records (ie. EVERY tank you buy gets recorded) then you really don't know your MPG.  Having kept record of every drop of fuel burned over the last 3 years I can say with confidence that I get:
- 6.3 MPG (Canuck gallon) at 110 km towing/Aquahot combined
- 8.5 MPG if I slow to 80 km

8-92 with 10 spd Roadranger, geared for 1700 RPM at 110 km.

Title: Re: Fuel economy (again)
Post by: norcal_kyle on June 19, 2007, 01:43:13 PM
my Eagle 10 w/ 24.5" wheels and a 350hp 6v92TA/740 gets 8-9mpg on the highway, and around 6, sometimes 7mpg in the city and on hills. the best i have ever seen on my rig was averaging at exactly 10mpg on a trip from sacramento, ca to seattle, wa a few months ago. the stretch of road was from sacramento up I-5 north till just past shasta, right before you hit the mountains. its not 12mpg(i wish, haha) but i think its pretty good for a machine that weighs almost 20 tons. lol.
Title: Re: Fuel economy (again)
Post by: JackConrad on June 19, 2007, 02:03:37 PM
When we first started converting our MC-8, (empty shell with sleeping bags and a Coleman stove) we were getting 7-7.5 MPG. After the conversion was finished, we are getting 6-6.5. This trip we are trying something different. Since we are on no time schedule, we are traveling on non interstate highways at 55-60 MPH, instead of 70-75 on the interstates. We have not had to fill up yet, so I do not how much difference, if any, this will make. We will proably go fill up sometime in the next week or two while we are at friends on the NV/VA border. I will post the results when we do. Although 1 tank full will not be a real accurate indicator, it should show an indication of any difference.  Jack
Title: Re: Fuel economy (again)
Post by: scottwms on June 19, 2007, 02:12:05 PM
meaningless?  full tank to full tank, miles using gps.
Title: Re: Fuel economy (again)
Post by: Dallas on June 19, 2007, 02:20:09 PM
When I ran my trucks, I didn't much worry about tank to tank fuel mileage, except in a passing manner.
What was important was the quarterly fuel mileage and the yearly fuel mileage.
There are too many variables in terrain and even in fuel bought from one fuel stop to the next.

Of course this was in trucks that ran 100,000 to 200,000 miles a year.

Using the quarterly fuel mileages I could tell what kind of driver I had behind the wheel, how much "Cowboying" he did, and even if he had a habit of going off route by very much.
Using yearly mileage I could decide how much fuel bonus to pay based on as little as 1/10 mpg.

Since we aren't running hard and long with our buses, the yearly may not mean much, but the average over a number of trips certainly will.

Dallas

                      GO BUSSING!
Title: Re: Fuel economy (again)
Post by: Gary '79 5C on June 19, 2007, 03:00:35 PM
Jack,
I think that you and a few others hit it on the head, with the speed factor. I am not retired and ahve a 5C w/ 6V92TA large injectors. I run at 70 from NJ to FLA. 1200 miles @ 6.7 mpg. I need to start earlier and drive longer legs all at 60 MPH. I think that is really a big factor. I understand hills and mountains out west will detract from milage. But speed is a killer as well.
P.S. I have a 4 spd auto Allison, but nowhere near the mileage of the Eagle 10 NorKal is running. I must be 5,000 lbs lighter as well.

Good Luck All, from NJ with $ 2.52 / gal.

Gary
Title: Re: Fuel economy (again)
Post by: JimC on June 19, 2007, 07:15:10 PM
I have a 4106 with 8V71 and a 730 automatic trans. I averaged 7.6 mpg last year, with two trips getting 8.1 . As Jack said, it depends on how much of a hurry I am in more than anything else.
Jim