Question about Country Coach w/ Cat C9 3mpg & low power

[twojayhawks]

I won't add any more speculation on what is wrong but I will agree there is certainly something wrong. Unless you pushed a sustained 40 mph headwind 3 mpg spells investigation and quickly. Here's to it turning out to be a small inexpensive issue!

[0phantom0]

UPDATE:
The RV shop has had the coach for about 2 weeks. They replaced (when I say replaced I actually mean PLACED since the old exhaust was rusted and mostly fallen off) from the muffler on back. There were so many holes in the exhaust I was probably getting some back pressure due to uneven flow.
They said the trans fluid was not Transynd but regular fluid. Strange because my last receipt from prior owner was done 2 yrs ago at Caterpillar. But the price was only ~$300 so there's no way they used Transynd. So they replaced that.
They also replaced all the filters, especially fuel filters. Said it was disgusting from sitting for 18 months.
Lastly they found a *fuel leak* at the top of the engine. Had to go in from the coach side. It was a quick release fitting that was leaking. They said it was only dripping not really streaming but I suspect that it could have been dumping a lot of fuel. Probably while driving it 300 miles it shifted and reseated a bit. I suspect that's one of the main causes for the low fuel economy. Sure I probably lost 1-2 from the exhaust and 1-2 from the fuel filter but to get 3mpg WITHOUT TOAD it makes sense it was dumping raw fuel.
I haven't driven the coach yet but I'll update to see if those items fixed the issue.

[Cat320]

Originally Posted by Mr_D

Note that I never said it was an average, I said the VMS showed that on the flat and level, no wind conditions.

Mine does the same thing...that's not a true MPG. Run a couple of FULL tanks through, and do the MPG with a #2 pencil. That's your accurate MPG.

[Gary RVRoamer]

A 3 mpg you should be seeing clouds of smoke behind you, from unburnt fuel passing through the engine and into the exhaust. If not, it must be leaking out somewhere (which seems a more likely explanation). I'd start checking fuel lines and filters for leaks.

That coach has a larger engine and better tranny, but it also weighs a whole bunch more, roughly 10k more. Performance is pretty much determined by the weight/Hp ratio and both coaches are probably around 100 lbs/hp.

Per the brochure, the biggest 99 Bounder Diesel maxed out at 24,850. The CC Inspire specs out at more like 33,200.

[2 Stroker]

I had the same fuel leak on top of the motor dripping off the bell housing. Had to pull the mirrors and lift the floor to reach it. Country Coach did use a quick release fitting that is used in air lines. It is a 1/2" plastic return line to the tank coming off of the back of the head, used a compression fitting for a replacement.
2 stroker

[0phantom0]

Originally Posted by 2 Stroker

I had the same fuel leak on top of the motor dripping off the bell housing. Had to pull the mirrors and lift the floor to reach it. Country Coach did use a quick release fitting that is used in air lines. It is a 1/2" plastic return line to the tank coming off of the back of the head, used a compression fitting for a replacement.
2 stroker

Yes thats the fitting thats leaking. I think thats the main culprit. Probably losing 1-2 mpg for the fuel filter, exhaust, etc but losing the rest just dumping it off that fitting