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Topic: I need to get better fuel milage. Maybe the H... (Read 791 times) previous topic - next topic
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I need to get better fuel milage. Maybe the H...

Yahoo Message Number: 94492
Fuel mileage can be difficult to get a handle on. First, things like the generator, aqua hot, will use fuel if running, winds, elevation changes, etc can affect it as well.
The next big thing is to check the odometer to be sure it is accurate. Your GPS can be sued to determine this. Use the trip computer function of the GPS.
The next thing to consider, if you are relying on a Silverleaf or such, is it recording the real mileage. Be sure it is accurate. If it is under recording miles it will show reduced MPG.

We all know driving habits, terrain etc will also affext it.

Mikee

Re: I need to get better fuel milage. Maybe the H...

Reply #1 –
Yahoo Message Number: 94496
On the transmission shift pad there is a button in the upper right corner that says mode. When you push it a light will come on and switch the trans to either performance or economy mode. Now here is the tricky part. One mode is the default and one is selected when the light comes on. It can be programmed either way, there should be a label next to the light that says perf or econ. That is the mode when the light comes on, if there is no label then you have to drive in each mode to determine which is which. In the economy mode it will shift earlier and hold the gear longer for slightly improved mileage. In perf mode it will shift later and downshift wuicker to keep the engine closer to the HP RPM range. In the economy mode it tends to stay closer to the torque RPM range.
The economy mode works well for most driving conditions. The perf mode is better for hills or heavy towing.

Mikee

Re: I need to get better fuel milage. Maybe the H...

Reply #2 –
Yahoo Message Number: 94497
I would like to hear of a good way to test the CAC for leaks. I'm getting low 7's for mileage and have up to 32lbs boost pressure according to the Silverleaf.

Tom R

2006 Intrigue 12057
400 ISL

Re: I need to get better fuel milage. Maybe the H...

Reply #3 –
Yahoo Message Number: 94498
If you are getting 32 lbs that's very good. In my case there was just enough leak to effect the midrange performance and yet not effect the full out put of the turbo. So that meant I could go up hills at full power but when I was cruising, I was not doing so efficiently. They remove the hose from the accessible side of the charge air cooler and plug it . Then they go in from the top and disconnect the pipe and and plug it with a rubber fitting with a pressure gauge and air fitting. They charge the CAC and it has to hold a certain pressure for 60 seconds, mine failed at 40 seconds on the Allure. The Intrigue for only 10 seconds. When Dave Remington at OMC sprayed the bottom of the CAC radiator with liquid soap the radiator looked like Lawrence Welk's bubble machine. But truthfully I found the Fan controller effected the fuel milage more than the CAC.

One snide remark if I may, All Cummins people know we don't have a Cat, but but not a dog either, and that we get over 1 mpg better milage than an equivalent Cat. ISL vs C-9. ISX 12 vs C-13 and the 600 ISX vs the 600 Cat. I wanted at ISM in my Intrigue, but all I could get at the time was a C-12. so I stuck with the ISL. I'm glad I did, it gets me anywhere I want to go. It won't keep up with a 45" Magna and a 600 or 650, but it will keep up with a 45' Affinity or Magna with a C-13 or a Prevost with a Detroit.
TWI 2004 Intrigue 11731

Re: I need to get better fuel milage. Maybe the H...

Reply #4 –
Yahoo Message Number: 94499
If you are getting 32 psi of boost and that is the max for your engine it is not leaking. You may just want to tighten, check the clamps.

Mikee
 

Re: I need to get better fuel milage. Maybe the H...

Reply #5 –
Yahoo Message Number: 94506
Tom, first climb into your engine box with flashlight and look carefully at you exhaust manifold, look for any "black soot lines" top then under coach look at the bottom of exhaust manifold.. the ISL's are famous for cracked exhaust manifolds.
Second follow your CAC Piping at each clamp tighten them all the way to the exhaust tip and again look for any "black soot lines" that's an for sure indication of a leak. But if the CAC itself is leaking it may be hard to detect without the actual pressure test.

Mike 03 Allure 1st Ave. #30898