What's the difference between Cummins diesel and Cat diesel.

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15 razor xp

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-Looking into buying a DP motorhome for the purpose  going full time RV's. Been looking at 37ft. to 40ft. ,notice some have Cummins and others have Cat diesel. What are the differences -  as far as drive ability, reliability, if any. Looking at MH between 2000 - 2006  year's.
 
Cummins get slightly better fuel mileage.  That's not enough to steer me in either direction.  Both are pretty bulletproof if you take care of them.

Cat dropped out of the over road business several years ago.

I've been driving a Cat C7 for 6 years and haven't had a single problem.  For me the only difficult part of maintaining it is changing the secondary fuel filter.  Messy job that has to be done from under the bed of our motorhome.  I.e. Don't spill a single drop of diesel fuel!
 
Cummins has 'sleeved' cylinders which can result in erosion, see here. The big CATs on our boat have no such issue, but CAT's recall for issues leaves something to be desired.
 
There is no difference that would lead you to choose one motorhome over the other because of the engine brand. Forget engine brand and focus on more important matters, like suitability of floor plan, state of maintenance, tire age & condition, etc.
 
you will find out the difference between Cat and Cummins when you need replacement parts.
 
Most Cat's in motorhomes have the rear mounted radiators that can be problematic if not cared for often.>>>D  ( Don.t take me too serious, I have many friends with Cats and I love to give them a bad time)      "meow"
 
We have over 600k miles on the son's KW with Cat C4.4 motor. I love the sound of a Cat engine rolling down the highway.

 
lavarock1210 said:
AND that is??
the joke I use to hear around the truck repair shops is.... Cat paints everything yellow because it's the same price as Gold.
 
My friend a mechanic at Kenworth when a Kenworth with Cat million mile club decal pulls in
Sez to his service manager you'll never see that on a Cummins
Bob 96 Safari 3126 Cat
 
Robert K said:
My friend a mechanic at Kenworth when a Kenworth with Cat million mile club decal pulls in
Sez to his service manager you'll never see that on a Cummins
Bob 96 Safari 3126 Cat
some truckers may say you won't see a Kenworth with a million miles no mater what motor it has,  many viewed Kenworths as farm equipment .....the old joke was..."what's a Ken worth ?  ...not much".    .

then there was the    "old truckers never quit....they just get a new Peter built" ...and  " the Detroit diesel is a controlled oil leak "

I'm just telling you what I used to hear around truckers..I've had all 3 in work trucks, Cat, Cummins and a Detroit.    they were all good motors.

IMO.  just about every diesel motor being used today is a perfectly adequate engine that will get your motorhome anywhere you want to go,
I'll bet any of the diesel engines (properly maintained) will outlast most of the mid level motorhomes of today.
 
Don't forget about the trans.,  the word I hear,  the bigger the Allison, the better the Allison.

for me...it would be far more important to just get a great diesel motorhome that I loved for the layout and the options... 
(*with a power to weight ratio of not less than one to a hundred and a side radiator ). 
:)

 
15 razor xp said:
-Looking into buying a DP motorhome for the purpose  going full time RV's. Been looking at 37ft. to 40ft. ,notice some have Cummins and others have Cat diesel. What are the differences -  as far as drive ability, reliability, if any. Looking at MH between 2000 - 2006  year's.
Putting this in perspective.  Which makes a better truck to tow a trailer, Ford, Chevy or Dodge?????  People are going to go with good or bad experiences or war stories from others and argue about which are better.

As Gary replied earlier, focus on the RV and not the engine. 

Also do the recommended maintenance.
 

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