I asked something similar to the Duramax guys, so I'll see what difference of opinions I get.


But my thinking is like this... If I'm looking for the best engine durability, I know the traditional answer has been the CTD. I have read about the million mile engines, and everything. But, I think power levels have a lot to do with it. I imagine the 5.9 was orginally designed for only about 150 HP or so. Those million mile trucks are probably from back when it was about 175 HP in the trucks. Now, with it having 325, I have to believe that almost doubling the power of an engine is going to seriously affect engine life. The highest it now has in the medium duty trucks is about 250, and highest for contiuous marine use is around the same. I doubt any of the new trucks have extremely high miles yet, so I wonder how much this squeezing of the same design will shorten its life.


But on the other hand, the Duramax is a new design, and I imagine it was actually designed for the 300+ HP that it has in the trucks. That makes me think it might be better equipped handle that much power for longer.


So, is this crazy, or could it be a good point?

I think the key here is rpms. The lower the more durable generally speaking.

Also depends on how they are used. If an engine is rated at 300 but you are always relatively easy on it, it should last as designed. The best engines are the ones that last longer than their design intended... consistantly.Edited by: hoot

when you ask opinions of all these people dodge guys are going to tell you cummins chevy guys are going to tell you duramax and ford guys will tell you international why don't you take a trip down to your local dealers and look at all the used ones you can find and note the mileage and take them for a ride and make your own opinion you ask this question about once a week you seem to like the duramax go get one and give us your opinion. When I saw several cummins that freinds own that had 200,000+++++ miles it was a easy choice for me.

Hoot made a good point about RPM's. The Cummins can cruise all day up and down big hills and run in OD at 1500-2000 RPM's where the D/A likes to shift down a lot. That is my single biggest reason for liking the Dodge/Cummins better, is that it'll hold OD like no other. Also look at the weight difference. Even though the Cummins has smaller displacement it weighs what, about 300-400lbs more?

I think my Dodge came off the trailer at 7200 lbs

Dmax was 6400 delivered.

Same exact configuration trucks.

A cummins motor is build like a brick sh*t house and can take just about any amount of horsepower you want to put though it.


go to http://www.bankspower.com/Sidewinder.cfm and see the sidewinder project that is pushing 1300 ft/lbs. and 735 hp with no beefing it up. it still get 21 mpg.

Unfortunately an engine is only part of the picture. The entire system's ability to take added power is more important to most.


RPMs are important but equally important is stroke. And I'd bet the Cummins has a longer stroke than the Dmax.

I am actually looking into the purchase of a 95 dodge 12 valve truck that has 192000 miles on it, and the miles don't bother me at all.. The duramax will hold more actual power than I expected.. One person on this site has pulled 750 hp at the wheels (atleast 900 on motor) and I've seen the sheets to prove it.. This was with the stock turbo and non-oringed heads... I'm considering the 12 valve as a foundation to make atleast a 12 second truck.. If you go on ebay, you'll see many cummins trucks with very high mileage still bringing good money..

Those million mile trucks are probably from back when it was about 175 HP in the trucks. Now, with it having 325, I have to believe that almost doubling the power of an engine is going to seriously affect engine life.


But way back when --that same engine was also in other applications with higher HP and higher TQ doing the same thing. The bottom end is pretty stout!