So, I'll take a shot at this... eight American market diesel cars and trucks with the most impact on the market. (That doesn't necessarily mean sales, but rather impact
- how much was the market changed by that vehicle and what happened in response to it.)
- 1939 GMC AC-Series - As far as I can tell, this is the first truck application of the Detroit Series 71, which... yeah, that was kinda a big deal.
- 1977 Volkswagen Rabbit Diesel - Arguably, this was the first really successful affordable diesel here, and from a respected brand. And, it was part of an engine family that led to the first US TDIs, too.
- 1977 Mercedes-Benz 240D, 300D - This was the generation that would ultimately see, for 1982, Mercedes-Benz starting to back away from gasoline in the US market. That obviously didn't last, but it was still a thing that happened. Even though it wasn't exactly affordable, it definitely contributed to the mainstreaming of diesel here (partially just through being in the right place, at the right time), and has a very strong reputation that persists to this day.
- 1978 Oldsmobile Delta 88 Diesel (and many other GM models) - the first attempt to really, really mainstream diesel in the US market... and, well, we all know the story. It is worth noting that in 1982, the engine was hugely strengthened, but the reputation damage was already done, and dealers still didn't know how to fix them.
- 1983 Ford F-Series 6.9 Diesel - This is, I would argue, the engine that kept diesel pickups alive in the US. Sure, GM had already switched to the 6.2, but GM diesel was taking a huge reputation hit. And, the 6.2 at this time was only 135 hp, 240 lb-ft - contrast to the 6.9's 170 hp, 315 lb-ft. And, I'm actually going to leave the Dodge Ram Cummins off in favor of this - if it weren't for this, there wouldn't be a market for Dodge to launch the Cummins into, and this engine family was able to effectively respond to Cummins anyway (in direct injection and turbocharged form, as the 7.3 PowerStroke, although even the 6.9 had more horsepower than the initial Cummins, and the 7.3 IDI had a fair bit more).
- 1996 Passat TDI - it didn't directly have much impact on the market, but it literally launched the TDI brand - and with it, relaunched accessible diesels - here, so that's gotta be good for something.
- 2001 Freightliner (Mercedes-Benz) Sprinter - Even if it wasn't the best of the European vans at the time, it was clearly the best of what you could get here... if you could afford it. Incredible fuel efficiency compared to the American competition, far better cargo flexibility with the available high roof, and it's heavily influenced the American van market ever since. For 2004, a rebadged version replaced the Ram Van, and with Chrysler separating from Daimler, Fiat ended up bringing the Ducato (a Sprinter competitor) to replace the Sprinter's position in the Dodge/Ram lineup, with an available 3.0 diesel. For 2015, Ford's brought the Transit (a direct Sprinter competitor) here, with an available 3.2 diesel, and it's replaced the Econoline for most workloads. While GM's still stuck with the legacy American van layout, they're putting a small diesel (a 2.8) in for 2017...
- 2009 Jetta TDI - and I don't just mean Dieselgate. Like the 1978 Oldsmobile diesels that the CRs will inevitably be compared to - both getting branded with having killed diesel in the US - this was diesel's big mainstream push. Sure, the 1996 Passat brought pricing down to where the mainstream could get it, but the mainstream didn't want to get it. And, its initial success showed several automakers that there was demand for an accessible diesel product, and that it seemed feasible... but now, we all know that it wasn't actually feasible.
As far as the Liberty, it used a VM Motori 2.8 turbodiesel... closely related to the 2.8 "Duramax" used in the Colorado/Canyon, and soon to be used in the Express/Savana. (And, yes, nowadays, VM Motori is owned by Fiat. Just to add to the weirdness, the VM Motori 3.0 V6 used in the Ram 1500 and Jeep Grand Cherokee began as a 2.9 liter for European Cadillacs.) However, it had the problem that it ate transmissions for breakfast.