Originally Posted by Kathryn
Question for ya ...
Been looking at a 45 ft coach that comes with a "CAT pre-emission C-13 525hp engine..." or had an option available for a "Cummins 500HP ISM, pre-emission..." which was, I read somewhere, a $7K upgrade. Ads for several coaches with either engine are available, and of course, each owner claims their particular engine is "better".
I can give you real world info concerning the Cummins ISM. my wife and I have lived full time for the last 6 years in a coach powered by the ISM. Mine was built in Sept '02 as one of the last ISMs with no EGR fuel system. The EGR was the first generation of add on hardware for emissions control so it's a true pre-emissions engine. It's rated at 500 hp @ 2100 rpm and 1550 lb/ft of torque @ 1200 rpm. It's significantly lighter than the big block Cat. I now have 92,000 miles on the engine and my lifetime mpg is 7.8. This is with a 40,000 pound coach and a 4500 pound tow vehicle. I consider it to be one of the best engines ever put in a motorhomes. The engine and transmission have been completely trouble free (knock wood).
I obviously have no direct knowledge of the Cat C13. Both engines will be paired with an Allison 4000 transmission. Both engines will have an engine compression brake aka Jake brake. The Cummins Jake is 2 position and I assume the Cat is also. Some Cats engines used a fuel system known as "Acert" which was somewhat problematic but I have no idea if it was used in the C13.
Cat is out of the OTR business but there are many still in used in the trucking industry and off road equipment so parts and service are no problem. The ISM went out of production for the OTR business with the 2010 emissions requirements as Cummins did not want to spend the money to up date the fuel system. It was one of Cummins most successful mid sized heavy duty diesels.