Think that is good...the DD15 and the DD16 have a B50 life of 1.2 million miles.
I know you guys are going to ask so here is the explanation of the Diesel Engine Life Expectancy:
Engine makers use an engine-industry standard to design, test and estimate a product's life span. The result is the B rating, where B means the engine will produce power intermittently, with full power demanded no more than 80 percent of the time. (There are also A, C, D and E ratings based on different criteria.)
To the B is added a number indicating a percentage of a model's total population. For example, Paccar says its 12.9-liter MX diesel has a B10 rating of 1 million miles (the organized trucking industry's long-stated goal for over-the-road service). That means only 10 percent will not make it that far without rebuilding, or, to be more optimistic, 90 percent will.
Detroit Diesel says its DD13's B50 rating is 1 million miles, which means half of those engines should go that distance without rebuilding and half won't. The B50 for the DD15 and DD16 is 1.2 million miles. Detroit has many years of experience in such matters, so the estimates should be reliable. Other makers quote similar numbers. And careful maintenance of any engine should extend its life.
The B number also depends on the horsepower rating of a motor. A Detroit Series 60 at 470 HP setting will have a longer life than the same engine at a 515 hp setiing
"Gunner" USN Retired, Airdale
2004 Monaco Signature 44' Conquest. Detroit 60