Diesel used to be a big deal. A couple of decades ago, some governmental authorities and plenty of automakers thought that, one day, we’d all be driving diesel vehicles fueled by sustainable biofuel. Such a future was nearly made a reality in Europe, where diesel was the dominant fuel for passenger vehicles. There were breathless press releases from multiple automakers about how clean and good diesel was. Diesel’s future was indeed bright – but ten years ago today, that all changed. The Dieselgate scandal burst the bubble. As we remember this event, this Autopian is asking: what is the best diesel car?
In the post-Dieselgate world, diesel has retreated back to where it works best: fueling locomotives, heavy trucks, construction equipment, and more. Even in Europe, diesel isn’t nearly where it used to be. Now, the world is focused on just finding its way out of internal combustion, for a future powered by batteries and, sometimes, maybe hydrogen.
But car enthusiasts are a weird breed. We don’t always do what’s logical, and we don’t always follow the pack. “Diesel” might be a swear word in many regions, but some folks still cling to their compression ignition-powered cars. There’s good reason to: Historically, diesels have been capable of covering epic miles between overhauls while providing hybrid-like fuel economy. Then there’s the torque and the lovely clatter.
Choosing the best diesel would be hard for me. An easy pick would be a legend like the Volkswagen Touareg V10 TDI, the Audi Q7 V12 TDI, or the Volkswagen Phaeton V10 TDI. All of these diesels were designed during the craziest period of the Volkswagen Group’s history, when engineers got to flex their muscles, punching out mechanical works of art with pumped-up power figures for their day. Another great pick from this era would be Audi’s diesel racecars, which didn’t just go fast, but dominated the field for years. Audi proved that diesel didn’t have to be slow and unsophisticated. And then there was the time Opel made a diesel sportscar …
But I’m going to take my modern fangirl hat off and go in a different direction. I think the best diesel car is one that gets great fuel economy and will continue to drive upwards of a million miles with minimal futzing around. For that, I’m turning to the iconic Mercedes-Benz W123, which was built in the millions between late 1975 and 1986. Specifically, I’m going to choose a Mercedes-Benz 300CD Turbodiesel from the 1980s.
In their day, the diesel engines in these cars were an engineering marvel. The OM617 A 3.0-liter straight-five diesel was a pioneer in turbocharging, and it took Benz’s already nearly bulletproof powerplant and gave it an extra dose of power. These engines, at least here in the States, made 123 horsepower and 184 lb-ft of torque. That’s not a ton of juice today, but back in the 1980s, it was enough to slice an entire 8 seconds off of the 60 mph acceleration speeds of Mercedes-Benz’s naturally aspirated diesels.
This meant taking only 12 to 15 seconds or so to hit 60 rather than over 20 seconds. Yet, these cars still got over 20 mpg, even with aggressive driving, and sometimes above 30 mpg with really careful drivers. I also love how these engines were served up in some fun body styles, including a coupe! Nowadays, it’s not uncommon to see these still driving around with a crazy number of miles, and since they’re so simple compared to the diesels of today, they’re relatively easy for an enthusiast to keep around.
So, that’s my answer, the Mercedes diesels of the 1980s are the GOATs of oil-burning automobiles. What do you think is the best diesel car?
Top graphic image: Mercedes-Benz
Diesel cars were invented by European ladies to keep them busy while their husbands do the cooking. – Hank Hill
Naw in all seriousness, I really like TDI cars. Family member has a Sportwagen, its great! I greatly appreciate a simple diesel engine unchoked by problematic emissions equipment. They don’t exist anymore sadly. Of my fleet, I think the most that would benefit from a quality diesel would probably be my Tracker. They sold them in Euroland/International Markets with one, but I don’t think they were anything special.
“What do you think is the best diesel car?”
Pretty much anything newer. The point of a diesel is getting the most out out of a gallon whether it be torque, miles or both. Unfortunately these old Mercedes diesel engines are better at turning fuel into fine particulate soot.
I have seen modern engines swapped into these old chassis and the results were intriguing. So that might be an option.
So, not a 1980 Seville with the Olds diesel?
Not my idea of a good time but you do you.
I’d also like to mention Casey Putsch’s Omega sports car, powered by a 1.9L VW TDI engine.
It gets over 100 mpg thanks to its lightweight, aerodynamic design, can accelerate like the Corvette C7 Gran Sport and Dodge Viper he also owns, and he claims it could be around $20k in mass production.
https://www.youtube.com/watch?v=e8jH1LIDHqk
I’d LOVE to see The Autopian interview this guy and give his build the recognition it deserves.
Damn. That checks all the boxes for you, doesn’t it?
No.
I’d like to have an EV version using large-format LiFePO4 batteries with the bare minimum electronics required for everything to function. Imagine 600 horsepower and AWD in a sub-2,500 lb car.
“Imagine 600 horsepower and AWD in a sub-2,500 lb car.”
I imagine a trip to the ER or morgue might soon follow.
You don’t need a fast car for that to happen.
Depends how fast you want to get there.
I’ve got a hilariously dangerous electric trike for that. And it’s very CHEAP to run, although it would be a lot cheaper if I got a new streamlined body on it. It weighs about 80 lbs, and I can accelerate from 0-60 mph in around 7 seconds.
Once the front motors are installed, it’s going to be so much more dangerous…
You’re going to have the most interesting obituary.
Ok, we need a member’s rides for you. I wanna glimpse of the Toecutter madness
It probably won’t be anyone’s ‘Best’, but, honorable mention to the Mercedes E320 CDI, from 2005-2006. The OM648 is a real peach – last of the iron-block Inline-6 Mercedes engines, it’s basically an OM606 with common-rail direct-injection. The W211 is a great chassis – they’d worked out most of the quality issues by the time they started bringing diesels over, and the cars handle and brake an order of magnitude better than what you’d expect (Note – I did have wide AMG wheels and Bilstein HD shocks on mine). Quiet, comfortable cruiser, plenty of power, great sound, 40mpg, and it can handle some hot laps on track. They’re starting to be hard to come by in pristine condition, because they’re so easy to wrack miles up on. The guy who bought mine (shouldn’t have sold it) was a W123/W124 guy, but he was so amazed with the W211 that he went out and bought a second one within a year of driving mine, so his wife could drive it.
These are all great choices, but the correct answer is the HDJ81. The 1HD-FT is considered one of Toyota’s best engines in what is also considered to be one of Toyota’s best cars, the 80 series Land Cruiser. The 1HD is notoriously reliable, durable and tunable. Decent mileage considering the tech and platform too. My friends in a 1HD-FT powered Maltec 80 were getting close to 20 mpg average. Which for a 6500 lb full time 4wd camper on mud terrains, is fantastic.
The ridiculous Audi RS5 diesel concept. What a glorious, hilarious model. I wish they had sold a few!
Ford Trucks from 1994-1997.
Audi Q7 V12 TDI obliviously.
https://www.caranddriver.com/reviews/a15147530/2009-audi-q7-v12-tdi-diesel-review/
I know you said “cars”, but I’ll go off script. The Nissan turbodiesel in the late model Scouts was a pretty good engine. Likewise, the Cummins 6.7 in my Ram 2500 pulled like a freight train, but Stellantis parts bin crap like the TIPM and power steering system let me down. Still loved the sound of that Cummins firing up and the way it shook the whole truck when it would shut down.
Yeah, I’m going to agree with another commenter that the coupe is the hot-take favorite. I have a 300TD wagon, and it’s practically unkillable. It’s also versatile and useful.
I’m not going to agree with the W123 fans on FB who will say it’s the best car ever, but best Diesel? Quite possibly.
The Mercedes W116 300SD.
More reliable than even the W123s.
Easy, the W123 as pictured, but also the mid-1990s Dodge Ram diesel trucks. They are called “one-wire engines” because once started, they only need one wire to operate – and all that does is close the fuel solenoid. Those trucks can sell for more today with a quarter million miles on them than MSRP when new.
Honestly, my favorite diesel vehicle (not necessarily the best) was the early 1990’s Toyota Land Cruiser I drove in Kabul, Afghanistan. We had up-armored SUVs instead of MRAPs for a lot of reasons – cost, maintenance, maneuverability, fuel economy – but probably the least discussed was optics. At least in 2013ish we were trying to transition out of the “‘Merica knows what’s best for you” attitude and into a collaborative nation-building posture with an international coalition. The MRAP is a giant top-heavy AT-AT of a truck that, whether we want it to or not, signals “We are here to make you do things our way.”
The humble Toyota, though, signals approachability, could be fixed with local parts, and blended in far better. It had a naturally aspirated diesel engine good for about…130ish-HP when new? Coupled to a five-speed stickshift, and hauling around about 1-1.5 tons of extra armor and reinforced glass. Not fast, but really engaging to drive. First time I went out, the Army senior NCO looked me dead in the eyes and cordially remarked “Just letting you know, LT, if you wreck this car I will shoot you. Sir.”
We went out most days and sometimes we’d hear about other convoys taking the same routes and getting blown up. Got the living daylights scared out of me a few times but my crew all made it back safe.
Welp, that was 2013-2014. It’s a little sad to look back and see what all the blood, sweat, and tears we put in amounted to, but at least I have fond memories of that Toyota.
I’ll nominate any rat rod with a 2 stroke Detroit swap, there’s nothing like that sound.
Production car: F10 5-Series with the M57, great highway cruisers
Oh boy, the C123 are actually far and away the WORST version of the W123 chassis. I found this out the hard way. The Coupe, and only the Coupe had some very poor design decisions made when it came to changing the layout and water passages for the body of the car. What this resulted in is a tendency for the chassis to rust apart, but only in areas that are not possible to be seen unless you look in very, very specific and hard to reach areas. One involves climbing into the passenger footwell upside down and peering into a small crack between the dash, and the other requires removing the gargantuan battery to see if it’s tray has disintegrated or not.
The result is a car that can look very solid, as my 1982 did, but is actually a complete and total death trap that requires incredibly invasive repair to remedy. In fact, the easiest way to test to see if a coupe is about to split into a couple, is with the factory jack. Raise each corner individually, and open and close each side door. If (when) the rust gets into the chassis, there is so much flex in the body structure you can’t close the door. I lost several thousand on my 82 because of this, and once I found out the truth, I sold it to a W123 expert who knew exactly what the deal was, because I couldn’t sleep if I let some unknowing person end up with a deathtrap like I did.
On the other hand, despite the ubiquity and general unkillable nature of the OM617, the W123 is getting to a point where brake boosters are becoming nearly impossible to find having been NLA’d a long time ago. The master cylinders tend to fail, leaking brake fluid into the boosters, which corrode them from the inside out. Not to mention fixing vacuum leaks on those cars is a serious nightmare, and general repairs to things like the HVAC are horrendous in 2025, dealing with ancient fiber optics and vacuum lines, and brittle but expensive wood trim.
The Youtube channel Restore It did a C123 restoration a few years ago. There was so. much. rust. I still think it’s a very handsome car.
When I got my license, one of the family cars I was allowed to drive is worthy of this nomination: 1980 Peugeot 504 Diesel wagon. Very competent chassis/brakes and just enough power to get to 60 in a 55 mph world. The combination of slow and steady surely kept me alive so I could be stupid at a later date.
Personal Experience: 1980 Olds Diesel Custom Cruiser Wagon with the Fake Wood Trim.
The car was excellent. Big, solid, comfortable, well put together (it was a far cry from the lower level offerings of the Big 3), you could carry everyone and everything.
The engine was shit, but that wasn’t the question…
I saw a video of a fourth generation Camaro that someone had swapped in a Detroit 6.5 turbo diesel.
As for a production car, I’d nominate anything with the ridiculously overengineered Volkswagen V10.
Got to agree with the 123!
I was going to say a 12v Cummins but you said car and I have not researched the greatest into car diesels so I will just agree with the merc haha.
The 1.9 TDI cars were pretty good!
If it’s a diesel – it’s gotta be a Mercedes-Benz.
Except for the later W126 350SD/SDL – Those were crap.
Every once in a while I see one around, but it doesn’t seem like the fuel economy was worth the tradeoff on those versus gas. Well, my 560 isn’t a great example at 14mpg average but the smaller motors were probably a bit better on fuel and still performed better than the diesels.
I saw a poverty spec 350SD in Iceland – cloth seats and all that. It was pretty cool. But again, the v8s will actually get out of their own way.
The 300SDs were bulletproof
But going from the inline 5 to a 6 seemed to mess things up somehow.
Anything with mechanical-injection that can rev to at least 4,000 rpm, and is wrapped in a lightweight, aerodynamic, no-nonsense analogue vehicle.
I’m very partial to this OM606 conversion of a Datsun 240Z:
https://www.youtube.com/watch?v=T93pJN6nmBE
I used to own a Mercedes 300 SDL. It was the best built car I ever owned.
As the current owner of a 300SDL, I can confirm. The only reason I desire to get rid of it is to have something sporty again.
Going with the Mercedes theme, the E250 and GLE250 blutec motors. The OM651 is MUCH better than the bigger OM642 it replaced. More reliability, similar power, better fuel economy. Even though adblue was mandated, the systems were rarely ever a failure point.
The crown for me, goes to the w210 Mercedes of the late 90s.
It was the container that the turbocharged OM606 came wrapped in. An engine lovingly referred to as the Diesel 2JZ.