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[GMCnet] 4.8 MPG [message #324111] Thu, 21 September 2017 10:16 Go to previous message
glwgmc is currently offline  glwgmc   United States
Messages: 1014
Registered: June 2004
Karma:
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Today's smaller gas class As get around 8 MPG, larger gas jobs around 6. Smaller diesel rigs around 14, larger diesel coaches around 8. Our Prevost Country Coach has a GVW of just under 50,000 pounds. At an open scale in Oregon with full water, half fuel, empty black and gray tanks and loaded for a month long trip we weighed 43,000 pounds with both of us in the coach. We get between 7 and 8 in normal freeway driving at a legal 60 MPH towing a Mini Cooper S Clubman. The lowest I have seen over the last ten or so fuelings (usually done at around 50%) was 6.8 and the highest just under 8. The engine is a 12.7 Detroit Diesel Series 60 DECC 3 with an Allison auto trans that predates the use of DEF.

Our former 1998 Beaver Patroit had a GVW of 32,000 and got 7-8 pulling a Subaru Outback for four years all over North America with a 330 hp Cat.

Both of our GMCs got 8-9 depending on speed, headwinds, altitude and average grade without a tow car and 1 MPG less towing a Fiat Abarth on a tow dolly. One GMC was carbureted the other had FiTech EFI. The EFI rig was a bit better MPG overall but not by much, maybe 0.5 to no more than 1 MPG. Average speed made more difference than anything else. I always estimated about 0.5 +\- MPG for every 5 MPH change.

Jerry

Jerry Work
The Dovetail Joint
Fine furniture designed & hand crafted
in the 1907 former Masonic Temple building
in historic Kerby, OR
http://jerrywork.com
.......
Date: Wed, 20 Sep 2017 16:04:24 -0700
From: John Phillips
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] 4.8 MPG
Message-ID:

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what do the new class A gas MHs get?


On Wed, Sep 20, 2017 at 2:48 PM, Chris Tyler
wrote:

> Just to make you feel better, contemporary [to GMC MH] SOB class As
> usually only got 4-5 mpg routinely
> --
> 76 Glenbrook
>
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> GMCnet mailing list
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Jerry & Sharon Work
78 Royale
Kerby, OR
 
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