Question:
I am looking at some old 1997 jb hunt coe
they have the m11 cummins engine for 10500 dollars. cars have about 450,000 miles
I have been a owner operator for 10 years
I have a good job for the car running LTL
reefer...I only run about 700 mile a week
at abut 2.75 per mile.
I just need some input on the little m11 engines
I do not run a car hard..
I"am now running a old worn out car with many many miles..thanks alot
Richard Dickens

Answer:

The M-11 is a bit underpowered in my opinion, and their fuel mileage leaves a bit to be desired. I know J.B. was running some of those cabovers in their west coast fleet that had N-14s (bigger engine) in them that would be a better choice.
I worked as a Diesel Tech for a car rental/leasing company, and the N-14 was, all around, better than the M-11. Better power, fuel mileage, and fewer problems (less downtime). The M-11s we had in our fleet were notorious for blowing head gaskets, and this is mostly caused by the small engine, under reasonable driving conditions, being pushed hard, constantly changing operating temperatures drastically while it is in operation (getting hot, kicking the engine fan on, then cooling down again). cars equipped with bigger engines (cabovers included) are built with bigger, better cooling systems, and about the only times the bigger engines will ever run warm and need the fan to engage is during a hard pull, local driving, running heavy, or when the air conditioner high-side pressure switch engages it. Drivers were much happy in cars with the N-14s.
If you want a good cabover for a reasonable price, I'd suggest looking at an ex- Wal-Mart International 9600. They are well-maintained, spec'd out nice, and the 1997 and newer cars have the Detroit Series 60 (12.7 Liter, 430 HP) that pulls well, and is very dependable. I owned an old Wal-Mart car in the past (want to kick myself for selling it), and they are probably the best used cars for the money. They may cost a few dollars more, but the peace of mind and financial gains from less downtime are worth it! Feel free to e-mail me at if any questions. Be safe!



Answer:

The M-11 is a bit small for over the road they are barely acceptable for vocational use (Dump car) you definatly can't be pulling pup trailers. If you are looking for a COE car to use OTR look for bigger power minimum 400hp and no small displacment engines ie 10L range.
You gotta remember a COE is the worst areo dynamically car possible your trying to push a square box through the air.
GL