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Topic: Diesel fuel mileage (Read 2897 times) previous topic - next topic
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Re: Mileage

Reply #25 –
Yahoo Message Number: 35690
I have 1998 CC Magna with a Detroit Diesel Series 40 engine with an Allison 3060 transmission. I pull a Honda CRV and average 60 to 65 mph.
I get between 7.5 and 8.0 mpg depending on the terrain and wind.

Bob
CC 5489

Quote from: dsrosey2003

Re: Mileage

Reply #26 –
Yahoo Message Number: 57051
Hi David,

We get 6.5 to 8.5 on our 2004 SOB with a ISL 400-2 Cummins on a 37,600 GVWR. Depends on hills, head winds, and did you know, one will get a mile per gallon better average going from west to east because of the prevailing west to east winds. Checked that out with 5 crossings of the fruited plains.
I set the cruise at 60 mph unless the speed limit is less. Been told that for every 5 mph over 55 mph, one Generally looses 1 mpg. At my age, the only time I get in a hurry is on the way to the potty.

Chuck & Mary B

Laughlin, NV

Shelby Dog, Miss Kitty, Mr Lucky Cat

Mileage

Reply #27 –
Yahoo Message Number: 97726
I just proved, somewhat empirically, the old adage that if you go slow, you pay less. Tried two tankfuls (about 750 miles each) over I 40 through Tennessee, Arkansas, and part of Oklahoma. The terrain was similar, i.e. no big mountain ranges to cross. Pretty much the same climactic conditions, i.e. wind, temperature, etc. Set cruise at 64 for one tankful and 62 for the other. 6.1 mpg at 64 mph and 6.9 mpg at 62 mph. Obviously, this isn't a very scientific test, but I tried to keep things about equal with my driving.
This translates to a 13% improvement which then translates to about $50 saved on a $400 tank of diesel. Since I'm not in a particular hurry, I think I will continue to operate at 60-62 mph. Amazed at the coaches that fly by me at 70-75mph!

Dave Glen

'06 Magna 6591

Re: Mileage

Reply #28 –
Yahoo Message Number: 97727
Dave,

I agree with slow down and save money. I have averaged 7.00 mph for over 46,000 miles. Been all over the country. Flat lands to many mountains. Cat C-9 not the best mileage getter to begin with.


Jock Vargo

2005 Inspire
51428

Re: Mileage

Reply #29 –
Yahoo Message Number: 97728
Dave,

Nice of you to share your experiment with us. I have for a number of years set the speed control at 62 while towing our Honda and running the generator. I have averaged just under 8 mpg (Cat C10). I actually find it peaceful at the slower speeds watching the frenzy. You may some day read my book in the making "Life in the Right Hand Lane". Puns and political incorrectness in abundance.

Tom & Patty Crews
2000 Magna - 5764
2005 Honda Pilot

Re: Mileage

Reply #30 –
Yahoo Message Number: 97729
Dave

We have just put 5k on our coach and experienced some of the same differences based on speed and with the addition of improvements using "Economy" and Cruise Control gave us ranges from 6.2 to 7.4 mpg. I have frequently forgot to push the Economy and later did the calculation for MPG and realized the difference. Thanks for you post. Larry & Linda 2003 CC Magna #6279

Re: Mileage

Reply #31 –
Yahoo Message Number: 97730
My cruise stays on 64-65 mph. Ocassionally, faster if I get trapped. My C-9 always gets about 7 mph no matter! Just had the valve lash adjustment done & they were somewhat out of spec so I interested in seeing how that helps mph....
D Jean
CC81072
 

Mileage

Reply #32 –
Yahoo Message Number: 97735
Dave, Yes, the slower speed really works. Once we were traveling with Friends that would not ever drive faster that 55 mph. I got 10 mpg on flat level highway terrain, verses the normal 8.5-9 mpg I get at 62 mph for the same road conditions. According to Cummins techs, the 62 mph (about 1,600 engine RPM) is the maximum efficiently speed for my 8.3/ISC Engine.. The problem at 55 mpg is staying focused on the road, going that slow tends to allow my eyes to wonder too much.. I also noted an increase in fuel mileage at about 100K miles on the engine.. Once again the Cummin Techs, Said "Yep, that is typical"..
Lee Casebeer x 36 ft. '01 Intrigue with 147K