Hi guys, my dad has a journey motorhome with the cummins 275. He used to get about 14 mpg and is down to about 10 now with only 45k on the clock. Does the computer on this beast adapt to the driver like some do? Any ideas on how to get better milage and performance from it?

 

I think that he should check all of his filters first. There is noreason for the mileage to decrease.

If the filters don't help, perhaps the timing has slipped. Is there any white smoke?

 

He replaced all of the filters recently and there is no white smoke. The MH is almost brand new. He drives alot because he's a pro dog handler. I told him that they usually increase milage as they break in. I read a thread someplace about adaptive memory in some of the computers where they adjust themselves to the driving conditions. Don't know if that could be a factor. I'll tell him to unplug the battery for awhile and check his milage going home against the milage coming here. Guess that'll tell me if it's a puter issue.

 

Is this the 275hp ISB? We have run into alot of problems with fuel mileage complaints. Here is a list of the most common found problems.

Dirty Fuel Filter

Dirty Air Filter: I dont know why, but it seems that owners dont change the filters on motorhomes like they should.

Weak Lift Pump: Many have been traced back to a weak lift pump. The downside is that most of the time when you catch the weak lift pump, it has already done damage to the VP44. More times than not, we have changed the lift pump due to low psi. Only for the coach to come back in a month or so needing a VP44.

 

Yes, it is the ISB. Would the edge ez chip work on the ISB? Or is there a better chip on the market for the ISB? The filters have all been changed so I'll have him check the lift pump.

 

Quite a few folks around me have been complaining of poorer mileage, both gas and diesel, lately.
My feeling is the oil companies rather than raise prices are watering down the fuel.

 

Yes, Im sure the EZ would work fine, but would not have any positive effect on fuel mileage.

 

Spunbearing, you are a man after my own heart "fuel mileage is bad ... will an EZ fit on it"

Gotta love these Cummins people!

 

hehe well personally I think that 10 mpg is pretty darn good for a 32 ft motorhome. But my dad is *complaining* because he was getting better milage with his gasser and a banks kit. He was getting 14 mpg before though on the cummins. He was getting close to 20 with his gasser.

 

20 MPG with a gas motorhome??? Was it a tiny Toyota???

 

I hate to do it, but I'm going to have to hit the BS button on that one.

 

It was a vectra with a V-8 and a banks kit. He averaged 18 -19 mpg.

 

Look on the bright side. That same motorhome with a 3126 will only avg. 7-8mpg. Where did he go when he got 14mpg? Was the terrain the same as when he was getting 7-8? Was he driving into the wind?

 

probably just driving down the cuesta grade.

 

Well he bought it new a year and a half ago and put 45,000 miles on it. He lives in the mojave desert and drives all over showing dogs. He said he was getting 14 mpg from the time it was new until just recently. I thought that they were supposed to get better milage as they broke in. Maybe his lift pump is going out? He'll have to put a guage on it.