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Old 07-03-2013, 01:24 PM   #15
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Originally Posted by 336muffin View Post
Air filter
...or a pin hole leak in a fuel line.

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DD 500
Pulling a Honda CRV
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Old 07-03-2013, 04:43 PM   #16
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Originally Posted by talrogers View Post
I have a 40 ft. Safari Zanzibar powered by a 370 Cummins deisel. My last milage calc. was 4.7 mpg. What should I expect to get? What should I look at first?
Air filter is the first thing I would check. Also tire pressure. CAC could do that to you. Have you owned the coach long. If so, what was your mileage before this. Let us know a little more about your coach ad how long you have had it. good luck..

2003 Newmar Kountry Star 3905, Freightliner XC chassis with CAT 330. Winnie the black lab, pretty Airbus captain wife, retired airline pilot with 11 grandkids. UH-1 pilot (Huey) U.S. Army 1967-1983. RVN 68-69. Northern Idaho my summer home.
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Old 07-04-2013, 05:22 AM   #17
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Im with Engineer Mike on this... get the boost checked. Even a pressure loss of 5psi will drastically reduce the MPG while you may not "feel" that power loss if you're not working it too hard. Have you noticed a big drop in power? When you take it in have them check injectors (contribution) and pressure on the rail as well - just 1 or two damaged injectors can ruin MPG quick, fast and in a hurry. Have you pulled the oil dipstick lately to see oil level? Bad injectors can fail and wash the cylinders down quickly. In rare cases it begins to collect in the oil pan thus raising the oil level on the stick....
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Old 07-04-2013, 10:00 AM   #18
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One additional item is, how are you calculating the fuel mileage? Are you taking it off the computer or doing it yourself after each fill.
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Old 07-04-2013, 05:51 PM   #19
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I have traveled from Washington State to Key West, FL and back the past four years, and I get a consistent 8 MPG on my CAT 350. I am pulling a CRV and set the cruise on 60 MPH. Dick
Bev & Dick and Fuzzy the cat
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Old 07-12-2013, 01:49 PM   #20
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Several things come to mind. Air filters clogged up a bit, the way you drive, the speed you drive,weight, and tire pressure. I get between 7-8 towing a Grand Cherokee.
Tony & Ruth........... FMCA#F416727
Newmar Dutch Star 4320, Spartan MM Chassis, Cat C9, Jeep Grand Cherokee,with Hemi, hooked up with a Blue Ox Aventa LX, and Brake Buddy.
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Old 07-16-2013, 04:20 PM   #21
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High speed will = reduced fuel milage, generator will be about .5-1 gallon/hr, diesel heating system will impact your milage too. Going down the road with a Cummigs ISL400 we get about 7-8 mpg however when I'm running my utilities It drops to about 5-5.5 mpg. Calculated at fill ups.
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Old 07-16-2013, 05:11 PM   #22
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Is the Zanzibar new to you ? With mileage figures that far from normal , it sounds more like a calculation problem ..

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