Technical advances in diesel engines and drivelines.

Personally, I love my 1995 12 valve Cummins, all 230hp. I am in no hurry and it pulls my toad just fine. Yes I cannot go 60mph up a lot of hills and just stay to the right to let everyone else by if thy need to go faster. The engine is easy to work on and the Allison 6 speed is electronically controlled and has given no problems. Another big puls for me is I have no slides to worry about. I just love it.

What are you looking for? The efficiency isn't enough that you would notice it on the fuel card, let alone pay for the newer machine. More power? Maybe on paper, but where are you going that you need that little extra? More reliable? Man I don't know about that. Lots of high tech expensive stuff on the new ones to go wrong. How much more reliable than an old diesel with no plugs to change are we going to get?

I bought an 01 to avoid the issue. It is great and with my resonator is even more powerful and spooks up the turbo faster. My buddy changed his 01 450 hp to a 500. Needed a new turbo and head to gang it on but it runs great. No way you could do this in the emission control engines. They are not more reliable and with def now they run hotter and as a result the builders need a bigger engine coolant package too.

OP, if I had to replace my 04 MH it would not be one with a engine newer than 06 so my answer to your question is NO. I find it strange that Scott would opt for a newer diesel but he drives a pre emission 03 Cummins (lightly bombed)... more smoke out the exhaust. The first emission mandated changes were on engines built in 04. To say these changes "were for power, reliability and efficiency (emissions)" is not true. What set me off was putting "efficiency (emissions)" together as that is not a positive relationship. To say that electronic controls increase reliability did not help either. 07 was the next emissions increase in complexity and cost and Cat gave up on making OTR engines before the 2010 increase. Navastar/MaxForce failed in meeting the 2010 absurd requirements and they are out of the MH business.
Tom is X2 BUT at least he knows to stay below 2010 (in most cases) DEF required engines. As each increase in complexity and cost came along (07 & 2010) some MH manufactures bought extra 06 & 09 engines to put in the next years MHs. I actually saw a 09 Monaco MH with a 06 engine in it so check which year engine is in it. It's easy to tell a 07 or newer, just look at the exhaust system... if it has wires running to it, it's a 07 or newer.
As for the Allison trannies, they are very reliable and from around 1998 they are electronic controlled BUT you do not want to work on the wiring harness, ECM, or even the shift pad. There is over 25 wires that replaced a lever and most of the time it works well but when it does not... GOOD LUCK
*OP, sorry about the rant and welcome to the forums.

ScottG wrote:
Yes, they're were huge changes made starting in about 2003 withthe advent of higher pressures, comon rails more electronic control over injector function. All of these changes were for power, reliability and efficiency (emissions). And that's just with engines. Transmission made leaps in efficiency and operation as well with the new electronic systems that control them.
Personally, I would opt for one of the newer powertrains over the previous generations. They run nicer, smoother, more quiet make more power and get the same or better fuel mileage as the the older models. They're also more reliable - but harder to work on for the DIY'r.

X2 and add, stay below the DEF required diesels. Not that I'm an expert, just any unnecessary cost and all that.

Yes, they're were huge changes made starting in about 2003 withthe advent of higher pressures, comon rails more electronic control over injector function. All of these changes were for power, reliability and efficiency (emissions). And that's just with engines. Transmission made leaps in efficiency and operation as well with the new electronic systems that control them.
Personally, I would opt for one of the newer powertrains over the previous generations. They run nicer, smoother, more quiet make more power and get the same or better fuel mileage as the the older models. They're also more reliable - but harder to work on for the DIY'r.