The newer ones with the 6.7 won't get 20+ mpg because of the emission crap. Also, the manual tranny is gone. There are no American trucks from the 1 ton on down with manuals. The last one was the Dodge 3500 a couple years ago.
I don't know about the last 3 or 4 years, but Dodge has had a problem with the steering parts wearing and causing what they call a death wobble, what we used to call a shimmy. The OEM steering parts and front hubs might need replacing after about 100k. If you can turn wrench at all, it's all fairly simple to DIY, then have an alignment. If it's the ball joints, that's another issue.
