Diesel Question

[B52Guy]

Mine is an '07 HR with a 400 Cummins and it doesn't require DEF or have a particulate filter. My gas mileage is about 8 and I run the generator usually running down the road. I have friends with that use DEF and they tell me their new Cummins is so clean the air coming out is actually cleaner than the air coming in....at least when they drive through LA...so they really feel they are doing their part for clean air.

[DD788Snipe]

Originally Posted by jacwjames

Funny, I know the manager of the local Cummins shop and he is currently looking for used coach and is looking for ~2006-7 model pre DEF type. He commented to me that the restrictions and regulations change so fast that the engine manufacturers really don't have a chance to "Get it Right" before it changes again.

If a piece of equipment didn't get hot enough the filter would be removed and put in a large oven that reached very hot temps to burn the soot out, along with compressed air to purge it.

I guess if I were looking for a new to me coach I would look for one without the DEF requirements and the need for regeneration. I don't think a motorhome is run hard enough, long enough to do a good job at keeping the systems working. Time will tell though.

My friends just bought a 2009 safari cheetah with 37,000mi on it a few months ago and have had nothing but problems with the DPF on the C-9 CAT. CAT got out of the over the road and Marine engine business because of the stringent smog rules imposed by big brother and they couldn't get a system to work all that well. I feel like they left owners out in the cold because they didn't solve the problems that have cropped up with the system on the few OTR engines they produced. Cummins, on the other hand, has had minimal problems. My rig, with a Cummins 370ISL, has no smog equipment and I love it and BTW I've never seen any black exhaust and my tail pipe is very clean so go figure.

[Old Scout]

I wont attempt to be as eloquent as Fire Up was with his explanation of new diesel engine technology but if you think all the "issues" with ULS fuel, DEF, EGR and DFP engines are behind us--I think you are "whistling past the graveyard." The shear technological complexity of these systems drove Cat out of the market--that cannot be dismissed lightly. Based on what I have heard and seen, RV owners will continue to deal with "check engine" lights and de-rated engines from things as miminal as malfunctioning DEF level sensors for sometime to come. Perhaps the engines are getting better--I am just not sure what model year I would declare "safe for prospective owners to come back in the DEF/DPF/EGR water."

[G Schulz]

Idling is something that is very hard on DPF filters. If the motorhome is not being used often it should not be run to lube up all the engine systems. The DPF requires high exhaust temperatures to burn itself clean again. My understanding is that the system won't regenerate itself on a Cat engine if the cruise control is on and also if the exhaust brake is on. No problem with mine yet but it only has 10,000 miles so far.


2009 Safari Cheetah 40'
350 HP Cat
2014 Ford Focus
Air Force One

[Cooperhawk]

I have a friend who is the fleet manager for a large trucking company. They currently have over 800 rigs on the road, mostly Kenworth. He has to keep a large number of older tractors on hand because the newest ones keep conking out over Environmental issues. The company is getting very discouraged with the newer equipment.

I know of another very large trucking company that is buying all the Pre-DEF Mack tractors they can find, refurbishing them, and putting them into service. Again, the newer models are unreliable.

Of course these examples are companies that put a lot more miles on their equipment than motorhomers do. I for one, after seeing the problems some of my friends have had with DEF, will steer clear of units 08 and newer. Too many diesel pickups that have given the owners way too much trouble, and the owners have gone back to gasoline powered vehicles.

[Smitty77]

OK, so I'll jump on the congrats to Scott the Fire Dude, for a great write up. And I feel Old Scout did a solid contribution to Scott's write up too.

While I feel the technology has been, and is, continued to be refined for this round of 'smog regulations' - I just don't know enough about these later engines to have an opinion if they've stabilized.

I personally, feel rapid series of seemingly 'ever changing smog regulations' on diesels has hurt both the OTR and RV industry. And when you her the OTR gang, that effect all of our pocket books. When changes are made in a vacuum by bureaucrats, with very little to none input from the discipline (Cummins, CAT, Detroit, Etc.) they are regulating. And then done so with multiple times over short periods of time. (And the PITA steps, and BIG $$$$ required to design, test, refine, and certify engines - are not to be taken lightly.) We get to where we are now.

Where are we now? Well CAT stepped out of the OTR for almost a decade. Owners have coaches with engines that even the manufactures are having trouble figuring out how to properly maintain/debug. Some have been fixed via multiple ECM upgrades, some maybe improved by the same. But some engines will have problems, and operating issues, for as long as their life cycle (likely a much shorter life cycle then is the norm for bigger diesels) will run.

We shopped for our coach I believe now three large smog rules changes ago. At that time, I targeted higher quality coaches, with engines that were pre 2006, and gave extra points to those without EGR's. The down side, is many of the engines I wanted ISM, Detroit and BIG BLOCK CAT's, were designed for pre ULSD change over. But, most of the bugs had been identified, and sure they still produced less power and lower MPG as a result of the ULSD - I felt they were much more mature in their engine management systems, just due to being around for 7+ years.

I feel anyone looking at a coach built within the series of these change upon change of regulations, should:
1) Check with the appropriate repair shop (Cummins, CAT, Detroit, Et.), and ask them if their are specific years to avoid. And call two or three shops, for opinions.

2) Check with owners of your specific coach, on Owner like forums. (IRV2 has great owner participation!0

3) Check with the Power Garage area for that specific engine. I browse the CAT, and spend lots of time on the Cummins forum. Very solid base of knowledge exits on these boards.

And when doing this, be sure to take the time when looking at a coach, to determine the exact year engine you have. For example, I have a 2004 model year coach, but have a July of 2003 built engine. Very common for large manufactures to have chassis and engines from an earlier year in their coaches.

I also have personally written my representatives at the National, and previous California State level, to voice my disgust with their process of changes. IMO, this should be 50 State only process, and should include strong participation by the engine manufacturers themselves. They should work on and target 5 year cycles of refinements to regulations. This would allow all manufactures to have a voice, and share their expertise, and also provide a reasonable amount of time to prepare for changes. It would also defer the costs out over a more reasonable timeframe. I know for sure, I don't like Executive Orders for anything, and don't want a politician getting 10 mins of good news time sound bits due to "What they're doing for...".

I'm in favor of reasonable changes, and intelligent reductions of pollutants. But the key word their is reasonable.

Buyer beware on specific engine and smog related issues, is a very good thing to add to your shopping for a coach education process!

Best to all,
Smitty

[Steve Ownby]

Originally Posted by Smitty77

OK, so I'll jump on the congrats to Scott the Fire Dude, for a great write up. And I feel Old Scout did a solid contribution to Scott's write up too.



While I feel the technology has been, and is, continued to be refined for this round of 'smog regulations' - I just don't know enough about these later engines to have an opinion if they've stabilized.



I personally, feel rapid series of seemingly 'ever changing smog regulations' on diesels has hurt both the OTR and RV industry. And when you her the OTR gang, that effect all of our pocket books. When changes are made in a vacuum by bureaucrats, with very little to none input from the discipline (Cummins, CAT, Detroit, Etc.) they are regulating. And then done so with multiple times over short periods of time. (And the PITA steps, and BIG $$$$ required to design, test, refine, and certify engines - are not to be taken lightly.) We get to where we are now.



Where are we now? Well CAT stepped out of the OTR for almost a decade. Owners have coaches with engines that even the manufactures are having trouble figuring out how to properly maintain/debug. Some have been fixed via multiple ECM upgrades, some maybe improved by the same. But some engines will have problems, and operating issues, for as long as their life cycle (likely a much shorter life cycle then is the norm for bigger diesels) will run.



We shopped for our coach I believe now three large smog rules changes ago. At that time, I targeted higher quality coaches, with engines that were pre 2006, and gave extra points to those without EGR's. The down side, is many of the engines I wanted ISM, Detroit and BIG BLOCK CAT's, were designed for pre ULSD change over. But, most of the bugs had been identified, and sure they still produced less power and lower MPG as a result of the ULSD - I felt they were much more mature in their engine management systems, just due to being around for 7+ years.



I feel anyone looking at a coach built within the series of these change upon change of regulations, should:

1) Check with the appropriate repair shop (Cummins, CAT, Detroit, Et.), and ask them if their are specific years to avoid. And call two or three shops, for opinions.



2) Check with owners of your specific coach, on Owner like forums. (IRV2 has great owner participation!0



3) Check with the Power Garage area for that specific engine. I browse the CAT, and spend lots of time on the Cummins forum. Very solid base of knowledge exits on these boards.



And when doing this, be sure to take the time when looking at a coach, to determine the exact year engine you have. For example, I have a 2004 model year coach, but have a July of 2003 built engine. Very common for large manufactures to have chassis and engines from an earlier year in their coaches.



I also have personally written my representatives at the National, and previous California State level, to voice my disgust with their process of changes. IMO, this should be 50 State only process, and should include strong participation by the engine manufacturers themselves. They should work on and target 5 year cycles of refinements to regulations. This would allow all manufactures to have a voice, and share their expertise, and also provide a reasonable amount of time to prepare for changes. It would also defer the costs out over a more reasonable timeframe. I know for sure, I don't like Executive Orders for anything, and don't want a politician getting 10 mins of good news time sound bits due to "What they're doing for...".



I'm in favor of reasonable changes, and intelligent reductions of pollutants. But the key word their is reasonable.



Buyer beware on specific engine and smog related issues, is a very good thing to add to your shopping for a coach education process!



Best to all,

Smitty

Truly well reasoned and outstanding post. Thanks Smitty.

2003 coach
Late 2002 Cummins ISM
non EGR
non DPF
non DEF
100 K miles
7.8 lifetime MPG

Runs great on ULSD and Bio
My AquaHot hates Bio below freezing.


Steve Ownby
Full time since '07

[dave&ginny]

You'll find pro's and con's to anything out there if you talk to enough people. As for the tag axles, if you carry or worry about carrying weight then get a tag axle. There is a ride difference and I love mine but not everybody wants one. I personally wanted the extra braking and load capacity.

As for the newer diesels......although I was against the exhaust fluid. When I'm warming up my diesel I don't have to worry about the neighbors smelling the old diesel exhaust anymore and so far mine has been worry free.

[road dogs]

I have read in several different forums that the new gen diesel trucks with DEF, DPF etc will not likely make the 300K-700K miles that the pre emissions motors would. I don't know if this applies to the bigger MH diesels or if it even holds true. Since the newer emissions stuff is still fairly recent, it remains to be seen. I'm going to hang on to my antique truck as long as I can. Anyway, I like the smell of old school diesel exhaust.....

[DD788Snipe]

Originally Posted by Smitty77

OK, so I'll jump on the congrats to Scott the Fire Dude, for a great write up. And I feel Old Scout did a solid contribution to Scott's write up too.

While I feel the technology has been, and is, continued to be refined for this round of 'smog regulations' - I just don't know enough about these later engines to have an opinion if they've stabilized.

I personally, feel rapid series of seemingly 'ever changing smog regulations' on diesels has hurt both the OTR and RV industry. And when you her the OTR gang, that effect all of our pocket books. When changes are made in a vacuum by bureaucrats, with very little to none input from the discipline (Cummins, CAT, Detroit, Etc.) they are regulating. And then done so with multiple times over short periods of time. (And the PITA steps, and BIG $$$$ required to design, test, refine, and certify engines - are not to be taken lightly.) We get to where we are now.

Where are we now? Well CAT stepped out of the OTR for almost a decade. Owners have coaches with engines that even the manufactures are having trouble figuring out how to properly maintain/debug. Some have been fixed via multiple ECM upgrades, some maybe improved by the same. But some engines will have problems, and operating issues, for as long as their life cycle (likely a much shorter life cycle then is the norm for bigger diesels) will run.

We shopped for our coach I believe now three large smog rules changes ago. At that time, I targeted higher quality coaches, with engines that were pre 2006, and gave extra points to those without EGR's. The down side, is many of the engines I wanted ISM, Detroit and BIG BLOCK CAT's, were designed for pre ULSD change over. But, most of the bugs had been identified, and sure they still produced less power and lower MPG as a result of the ULSD - I felt they were much more mature in their engine management systems, just due to being around for 7+ years.

I feel anyone looking at a coach built within the series of these change upon change of regulations, should:
1) Check with the appropriate repair shop (Cummins, CAT, Detroit, Et.), and ask them if their are specific years to avoid. And call two or three shops, for opinions.

2) Check with owners of your specific coach, on Owner like forums. (IRV2 has great owner participation!0

3) Check with the Power Garage area for that specific engine. I browse the CAT, and spend lots of time on the Cummins forum. Very solid base of knowledge exits on these boards.

And when doing this, be sure to take the time when looking at a coach, to determine the exact year engine you have. For example, I have a 2004 model year coach, but have a July of 2003 built engine. Very common for large manufactures to have chassis and engines from an earlier year in their coaches.

I also have personally written my representatives at the National, and previous California State level, to voice my disgust with their process of changes. IMO, this should be 50 State only process, and should include strong participation by the engine manufacturers themselves. They should work on and target 5 year cycles of refinements to regulations. This would allow all manufactures to have a voice, and share their expertise, and also provide a reasonable amount of time to prepare for changes. It would also defer the costs out over a more reasonable timeframe. I know for sure, I don't like Executive Orders for anything, and don't want a politician getting 10 mins of good news time sound bits due to "What they're doing for...".

I'm in favor of reasonable changes, and intelligent reductions of pollutants. But the key word their is reasonable.

Buyer beware on specific engine and smog related issues, is a very good thing to add to your shopping for a coach education process!

Best to all,
Smitty

Great post again Smitty. I definitely love the previous California residency statement. I too hope to be able to say that soon. Don't get me started but you hit the nail squarely on the head. Politicians will destroy an industry in order to garner votes and especially money from special interest groups and care nothing about the cost to the industry or it's customers, then throw them to the wolves. California is notorious for being run that way. I purchased my coach because 1. DW liked the FP and 2. It was pre 2007 smog. (I truly love the smell of burnt diesel folks). I put maybe 3000mi on my rig a year not 100,000 like OTR trucks as do most of us RVers. In the big picture the amout of smog that RV contribute to smog is very minimal at best.

[jondrew55]

Originally Posted by Pops90gt

We are considering a larger MH an I was told that in the last few years the diesel motors have had problems. He didn't specify which MH had them. So has anybody out there has any problems.
Also what are the advantage or disadvantage of a double rear axle.
Thanks

So Pops90gt, do you think you got your question answered?

I have a newer diesel MH and like it a lot.

[Pops90gt]

Thanks for all the response, I still have a lot of homework. Been looking at higher end MH's. Entegra, Phaeton, Charleston, etc. Also checking warranties, millage, towing plus the floor plan. The wife wants more counter space. So it maybe while.
Thanks Again

[EZDZIT]

Smitty, maybe your lobbying paid off!


We bought our coach new out of state in 2012. Please see signature. Before purchase, I was concerned that it might not meet California air quality standards but I found that the motor has a metal tag stating it does meet California standards. And, it passed a required inspection by California DMV prior to licensing. I believe that all of the new generation motorhome diesels are now 50 state qualified.

[Mainuh]

Interesting article here (2013) on what's going on in the commercial trucking world with respect to newer DPF-DEF vs the older "less regulated" versions: Gliders

I visited with a local older MCI bus conversion owner last week and he was explaining all about the Gliders which are becoming more and more prevalent. I wonder if anyone yet has re-fitted a newer coach with an older power plant and transmission combo.