I am no expert by any means but I bought an older Dodge Ram because my buddy at a four wheel shop said smog regulations were creating problems for diesel makers. Older models had less of that to contend with.
You might want to take a look at this article in Diesel Power magazine.
http://www.dieselpowermag.com/features/1201dp_10_best_used_diesel_trucks/viewall.html
In case the link fails here it is.
10 Best Used Diesel Trucks (and cars)
You Can Get A Steal of a Deal Now—Or Wish You Had Later!
Text By: Jason Sands, Mike McGlothlin
Diesel Power, January, 2012
People always ask us, “Which diesel should I buy?” While the correct answer to that question always depends on the person asking it, there’s no doubt some diesel vehicles are better than others. For almost every year, make, and model there’s a golden version in which the manufacturer did almost everything right—and we’re here to tell you which diesels those are. For example, if you’re looking to buy a used Ford, look at the ’08 models with the 6.4L Power Stroke rather than the ’07 Super Dutys with the 6.0L engine. The ’08 Power Stroke had more power, less warranty issues, and included a beefed-up 5R110 transmission to handle the power. As you’ll read in this article, there are also certain Dodge and GM trucks that are better than others.
Our 10 best used diesel list includes a wide range of makes, and we’ve even thrown in some vehicles that get great fuel economy. So if we were in the market for a new vehicle, here are the 10 best used diesels we’d look for.
2006 to 2007 Chevy and GMC 2500 and 3500
Although GM has produced its heavy-duty diesel trucks for more than 10 years, as far as we’re concerned, the ’06 to ’07 Silverado and Sierra LBZ-engine-code Duramax-equipped models are the ones to buy. Early LB7-engine-code Duramax trucks (’01 to ’04 model year) had injector issues, and LLY-engine-code Duramax trucks (built for ’04½ and ’05) had cooling issues while towing. The ’06 to ’07 LBZ-engine-code models had all the cooling and injector problems ironed out, but without all the emissions devices that were found on the ’071/2-and-later LMM- and LML-engine-code trucks. With the right parts, these Duramax vehicles can make more than 500 rwhp with simple bolt-ons.
2003 to 2004½ Dodge Ram 2500 and 3500
Common-rail injection ushered in a new era of technological advancement for the famed inline-six Cummins engines that have been offered in Dodge pickups since the ’89 model. The new powerplants burn cleaner and make more power—yet they are still the simplest of the modern diesels. Unfortunately, the change to ultra-low sulfur fuel combined with increased injection pressures has led to reduced injector life in new diesels. When ’05-and-later 5.9L Cummins engines have malfunctioning injectors, they can cause melted pistons, which can ultimately lead to a full engine rebuild. But the earlier common-rail Dodges (’03 to ’04½) seem to give the driver much more of a warning (in the form of a bunch of white smoke exiting the tailpipe) before they pop any pistons. Over-the-road haulers will want to look for cast-iron, NV5600 six-speed-equipped dualies from this era for their next tow rig.
10 Best Used Diesels Ford Super Duty Rear Three Quarter On Dyno
Most Durable Daily Driver: Ford Super Duty
1999½ to 2000 Ford Super Duty
Ford began offering the International-built 7.3L Power Stroke midway through the ’94 model year, but the late ’99 and ’00 trucks offer the best foundation for making horsepower. The first version of the Power Stroke was non-intercooled (’94½ to ’97), and the early ’99 engines came with the older-style high-pressure oil pumps. Buyers should note that California-spec ’97 trucks got split-shot injectors, and all ’97-and-later engines got a beefier block. By the time the ’01 to ’03 Super Dutys came out, International had begun equipping some of its 7.3L engines with the ill-fated powdered-metal connecting rods.
The late ’99 to ’00 model year is the jewel of 7.3L Power Stroke engines, due to having the proven, forged-steel connecting rods and 17 degree high-pressure oil pump (vs. 15 degree on ’94½ to early ’99 models) and being equipped with an intercooler from the factory. These forged-rod engines have proven they can handle more than 500 rwhp, be quite fuel efficient, and last forever.
10 Best Used Diesels Dodge Ram Front Three Quarter
Most Reliable: The Cummins 12-valve
1996 to 1998 Dodge Ram 2500 and 3500
The second-generation Dodges with the 5.9L P7100 pump 12-valve engines may just go down as the most reliable diesel trucks in history. It’s not uncommon for these pickups to make it more than 500,000 miles on the factory engine, and in most cases the truck rusts away and falls apart before the driveline does. Want power? These rigs are also some of the easiest to modify, with 400 rwhp available with just some bolt-ons, all the way up to 2,000 hp if the cash is there.
The best years to look for are the ’96 to ’98 models, which have updated transmissions and driveline parts, along with injection pumps that have more potential. If you’re looking for the small-block ’69 Camaro of diesels, it’s right here.
10 Best Used Diesels Ford Super Duty Front Three Quarter
Easiest to Modify: 600 hp with a tune
2008 to 2010 Ford F-250 and F-350
Part of the reason diesels have been so successful as hot rods is the fact that it’s relatively easy to crank up their power. And when you’re looking for the easiest one to crank up, look no further than the 6.4L Power Stroke. With nearly 600 rwhp available with just a tune, intake, and exhaust, ’08 to ’10 Fords are the baddest of the bolt-on bunch. The fact that they come in plush, comfortable trucks, have compound turbochargers from the factory, and are way more reliable than their 6.0L predecessors is simply icing on the cake. The ’08 to ’10 6.4Ls were also available in the F-450 pickup. These trucks came with only 325 hp and 600 lb-ft of torque but did offer larger axles, brakes, and wheels than the ’11 F-450 pickup does today.
`1991½ to 1993 Dodge
Although Dodge first crammed a Cummins inline-six into its ¾- and 1-ton pickups for the ’89, the ’91½ to ’93 models are the years to have. The mid-year models in ’91 saw a few important changes, namely, an overdrive transmission (also known as a 518) and an intercooler. With $1,000 in modifications, these trucks can reach the 300-rwhp mark and will run forever.
10 Best Used Diesels Bmw 335D Front Three Quarter
Best Hot Rod: Diesel sports car
2009 to 2011 BMW 335d
As far as we’re concerned, this one is in a class by itself. If you have $40,000 to spend on a new sports sedan, there’d be no better choice, diesel or gas. With 0-to-60-mph times in the 5-second zone, more than 30 mpg, a plush ride, and stunning looks, the list of reasons to buy one just goes on and on. The 3.0L engine’s sequential turbochargers are truly amazing. With a torque peak at only 1,700 rpm and a power peak at 4,200 rpm, the engine has arguably the widest powerband of any current diesel. Though it’s rated at 265 hp and 425 lb-ft of torque, our guess is it’s closer to 300 hp and 500 lb-ft, which makes it quite the rocket ship.
1999½ to 2003 VW Jetta Diesel
While nearly all new diesel Volkswagens blend performance and economy, the best of the lot are thought to be the ’99½ to ’03 Jettas, Beetles, Golfs, and Passats with the ALH-code engines. With a few bolt-ons, their anemic 90hp engines can be boosted to up to 150 hp. Owners of these lightweight cars report they can get 40 to 50 mpg and still have decent performance. For us, the Jetta is a good choice based on looks, interior space, and parts availability. We’d opt for the stronger manual transmission instead of the automatic. These little VWs can also be made into hot rods if the desire arises, as there were stripped-down Golfs running high 14s back in the late ’90s.
10 Best Used Diesels Jeep Liberty Front Three Quarter
4x4 Fuel Economy: 35-mpg SUV
2005 to 2006 Jeep Liberty CRD
On the fuel-efficient front, the short-lived Jeep Liberty CRD 4x4 gets our vote as a viable compact diesel option in diesel-scarce North America. Four-wheel-drive models are the best of both worlds: diesel power and off-road capablity. They were offered for just two model years (’05 and ’06), but that was enough time for the aftermarket to release several products, which solved minor EGR issues, added horsepower, and maximized fuel economy. With just two subtle modifications (fuel economy tune and aftermarket air filter), they’re capable of up to 35 mpg.
1981 to 1986 Toyota Pickup
Good luck finding one of these rare mini diesels, but if you do, you can count on more than 30 mpg in the city, and 40 mpg on the highway. These trucks are very simple to maintain, and the cost of ownership is very low. The model year to buy (if you can find it) is the one-year-only ’86 Toyota pickup, powered by a 2.4L turbodiesel making 93 hp. While the 0-to-60-mph times won’t impress anyone, the utility and mileage is hard to match—even with a newer truck.
