Quote Originally Posted by Nathan_Bell View Post
Avoid ALL of the new gen diesels. They all have issues.

Stick to the older diesels, you can get the power and fuel milage that folks think of when they discuss diesels. The new diesels get WORSE milage in a platform than a gasser will.
I wouldn't go that far. The newer diesels aren't as efficient as the ones from a few years ago, but they are still better than a gas motor especially when their output is taken into account. Only the Ford V10 comes close in power, but it will die trying to pull like a diesel over the long haul. The discontinued GM 8.1 with the Allison was close but still short of a strong diesel.

Of the post 2007 diesels with DPF systems, the Fords are the worst MPG wise. An in-law has a new F350 SRW and he gets 13-15 highway empty. My bro-in-law gets 17-18 highway empty in his 6.7L Cummins, and my 2008 GMC Duramax gets around 16-17 empty. In town is a good 3-4 MPGs less. My friend has an LBZ equipped GMC (basically the same motor I have without the DPF), and he gets about 1-2 MPGs higher than I do.

I will admit that the older diesels were more efficient. Plus they are easier to chip and tune than the new ones. Far less electronic interference from the computers.

I love my GMC Duramax, but if I was looking for a used diesel, I would look for this in order:

2007 GM's with the LBZ motor. Some of the older GMs are good, but the LBZ was the best of the pre-2007 motors (IMO). They also come with the excellent Allison tranny.
Ford 7.3's. I forget the years that these were made, but there are plenty of Super Duties and Excursions with this motor. Not as powerful, but responds well to tuning and is a good solid motor. Avoid the 6.0, as they are problem prone.
Dodge Cummins of just about any vintage as long as it has a manual tranny. The Cummins is an awesome motor. Powerful, robust, and a torque monster. It also turns automatic transmissions into dust. It wasn't until the lastest generation 6 spd that Dodge could put an auto behind it that would survive. The six speed manual trannies they used were pretty robust and lasted a lot longer than the autos.