Most Cadillac fans are aware that for about six and a half years, many Cadillac models were available with the unfortunate Oldsmobile 5.7-liter diesel V-8. Towards the end of that time, there was also ANOTHER diesel option: the Oldsmobile 4.3-liter diesel V-6, offered only on the downsized FWD C-body 1985 De Ville and Fleetwood. Sold in tiny numbers, it was more reliable than the diesel V-8, but it was one of the least-powerful engines Cadillac had offered since the 1920s, with what might have been the worst power-to-weight ratio of ANY postwar Cadillac.
Oldsmobile’s diesel engines were first conceived in 1973 as a low-investment fuel-efficient conversion of existing Olds spark ignition V-8s. This project took on new urgency following the federal Environmental Policy and Conservation Act of 1975 (EPCA), which established new Corporate Average Fuel Economy (CAFE) requirements for 1978 and beyond. GM senior management soon decided that the diesel should become a corporate engine, not an Olds exclusive. Oldsmobile motor engineer Tom Leonard later recalled that the diesel “caught on at the Corporation level, and all of a sudden they were putting the heat on us to do it. We got kind of rushed into it.”
The first production Olds diesel, the 350-cid (5,733 cc) LF9, arrived for 1978, initially offered only on full-size Oldsmobiles. It became optional on the Cadillac Seville late in the model year, and was extended to the Eldorado, De Ville, and Fleetwood Brougham for 1979. By 1980, the LF9 V-8 was available on most GM full-size cars. (There was also a short-lived LF7 diesel version of the smaller Olds 260 V-8, which wasn’t widely used.)
This proliferation proved to be an expensive disaster: Oldsmobile originally had very little experience with diesels (“Truck and Bus Group kept telling us, ‘There are so many pitfalls here that you don’t know about,'” Tom Leonard admitted later), so the LF9 and LF7 engines were underdeveloped, and the other divisions knew even less than Olds did about diesel repair and maintenance.
Between that and the poor quality of American diesel fuel, the diesel V-8s suffered a whole host of problems, including injector pump and head gasket failure, oil leaks, and broken crankshafts. Angry owners got organized, leading to class action lawsuits, a three-year FTC investigation, an FTC consent decree, and eventually a $22.5 million settlement agreement for most owners of 1978–1980 diesel cars. The whole fiasco soured many Americans on diesel engines generally and GM diesels in particular.
However, for a brief period in the late ’70s, diesel engines had seemed to be the hot ticket, with customers nervous about fuel shortages sometimes paying up to $1,000 over sticker price for oil-burning engines.
In November 1978, Oldsmobile began planning another new diesel engine, a 263-cid (4,287 cc) V-6 that would be smaller and lighter than the LF9, better suited for the downsized FWD cars then in the planning stages. This engine required much new tooling and a new plant to put it in, but GM anticipated that by 1985, as much as 25 percent of its lineup would be need to be diesel-powered for CAFE purposes. So, in spring 1979, corporate management approved construction of Oldsmobile’s big Delta Diesel Engine Plant, which had the capacity to turn out up to 1,600 diesel V-6s a day.
The new 4.3-liter diesel V-6, dubbed LT6, went into production for the 1982 model year, for both longitudinal RWD and transverse FWD applications. The 90-degree V-6 had a split pin crankshaft for even firing intervals, similar in principle to the even-fire Buick gasoline V-6. Longitudinal engines were all cast iron, but the transverse engine saved 62 lb with a different block casting, an aluminum intake manifold, and aluminum cylinder heads — the last were not often seen on diesels of the time.
Benefiting from Oldsmobile’s painful experience with the diesel V-8s, the V-6 was smoother and more durable than its V-8 cousins, with quicker starting and a water separator to keep moisture out of the injection pump. The 4.3-liter V-6 had only 85 net horsepower, 20 hp less than the 5.7-liter LF9 V-8, but in the lighter FWD A-bodies, its 165 lb-ft of torque made for acceptable acceleration as well as good fuel economy.
Cadillac didn’t immediately adopt the diesel V-6, although they continued to offer the Olds diesel V-8 on RWD full-size cars and the FWD Eldorado and Seville. The LF9 V-8 was actually standard on the wretched bustleback Seville in 1980–1981 and a no-cost option thereafter, but Road & Track found the diesel V-8 hopelessly overmatched by the Seville’s 4,200+ lbs of glitz and dreadful neo-Classical styling. With 40.5 lb of curb weight for each overworked horsepower, the oil-burner Seville needed over 21 seconds to reach 60 mph and wasn’t happy getting there — truly one of the worst Cadillacs of all time.
With the latest fuel crisis over, American buyers’ willingness to put up with diesel engine foibles quickly waned. Part of the problem was that the price of diesel fuel had risen until it was equal to or greater than the price of gasoline, but word had also gotten around about the terrible repair record of the earlier Olds diesel V-8s. Oldsmobile insisted the 1981 and later engines were much improved, but resale values of GM diesel cars had tanked, and fewer and fewer buyers were willing to take the chance.
Here’s the trajectory of Cadillac diesel installations through 1983:
However, Cadillac nonetheless decided to offer the 4.3-liter V-6 in the downsized FWD C-body, which arrived in the spring of 1984, somewhat behind schedule. Interestingly, while Buick and Oldsmobile charged a premium for the diesel V-6, Cadillac again made it a no-cost option, presumably more concerned with its anticipated effect on Cadillac CAFE calculations than with trying to separate buyers from a few hundred extra dollars.
The 4.3-liter V-6 wasn’t quite Cadillac’s least-powerful postwar engine — that particular booby prize goes to the 1982 Cadillac Cimarron, whose 1.8-liter four also had 85 net horsepower, with only 100 lb-ft of torque — but if you discount the Cimarron as not a REAL Cadillac, the LT6 diesel was the least-powerful engine Cadillac had offered since 1927.
If Cadillac had installed the LT6 diesel in the Eldorado, Seville, or RWD Fleetwood Brougham, all of which still weighed 2 tons or more, it would have made for the slowest Cadillacs in living memory. However, the FWD C-bodies were about 600 lb lighter than the older cars, which seemed more workable. The 1985 De Ville brochure offered this rather desperate-sounding appeal:
New for Cadillac, this dependable Diesel will give you the best of both worlds with all the positive characteristics inherent in a Diesel plus surprisingly responsive and smooth performance. The even-firing Diesel V6 furnishes the power to help you move “off the mark” smartly. But you really won’t realize just how responsive this Diesel engine is until you drive it yourself. People who have driven the new Diesel-powered Cadillac have been surprised and delighted. It’s that impressive.
I didn’t find any instrumented road tests of the new diesel De Ville, and the only driving impressions I found were a couple of one-line remarks in contemporary newspaper stories saying the diesel seemed surprisingly not bad.
How did the 4.3-liter diesel De Ville stand in terms of power-to-weight ratio? The base curb weight of a 1985 Cadillac Sedan de Ville was 3,396 lb; Car and Driver‘s well-equipped test car had an actual curb weight of 3,477 lb. Both of those figures were with the aluminum-block HT4100 V-8. While the LT6 diesel V-6 was lighter than the LF9 diesel V-8 (not offered in the FWD De Ville), there was still a weight penalty with the diesel, which included additional sound insulation and other equipment changes (like a standard engine block heater). I unfortunately don’t have the 1985 Cadillac MVMA specifications, which would give an exact figure, but from what I could determine, the weight penalty for a diesel De Ville was probably at least 100 lb, which would put its curb weight between 3,500 and 3,600 lb.
If we assume 3,577 lb (adding 100 lb to the C/D figure), that works out to a grim 42.1 pounds per horsepower, even worse than the diesel Seville Road & Track tested in December 1980, and MUCH worse than the similarly powerful but substantially lighter 1982 Cimarron. Even a late ’40s Fleetwood 75 limousine with the old L-head V-8, with 124 net horsepower to haul a curb weight of about 5,100 lb, had a fractionally better power-to-weight ratio!
Without instrumented performance tests, I can’t say for sure how “smartly” the diesel De Ville actually accelerated, but my guess is that its main performance advantage over the LF9 was that it was quieter and smoother, so trying to get it up to speed was less miserable. Throughout this period, Cadillac repeatedly insisted that its buyers were less interested in 0 to 60 or quarter-mile times than in step-off performance (0 to 15 mph) — the kind of thing that could be easily demonstrated in a leisurely test drive — and the diesel V-6 probably did all right there.
Very few De Ville owners were keen to find out for themselves. Looking at the production figures, it’s very clear that the decision to offer the diesel at all had been made well in advance of its actual introduction. By the 1984 model year, Cadillac buyers’ interest in diesel engines had fallen off so much I had to make a separate chart with a shorter Y-axis to illustrate it properly:
The diesel V-6 did offer encouraging 22/32 EPA ratings (adjusted combined rating of 23 mpg), compared to 17/24 for the HT4100 V-8 (18 mpg adjusted combined rating), but only 788 De Ville/Fleetwood buyers ordered it. Cadillac customers were no more interested in the LF9 diesel V-8, which was installed in only 207 1985 RWD Fleetwood Broughams, 76 1985 Eldorados, and a mere 40 1985 Sevilles. Here’s the complete tally of Cadillac diesel engine installations by model year for 1978 through 1985:
| Model Year | De Ville/Fleetwood RWD | De Ville/Fleetwood FWD | Eldorado | Seville | Total |
|---|---|---|---|---|---|
| 1978 | N/A | N/A | N/A | 2,800 | 2,800 |
| 1979 | 7,640 | N/A | 8,176 | 10,731 | 26,547 |
| 1980 | 18,765 | N/A | 12,424 | 14,461 | 45,650 |
| 1981 | 23,175 | N/A | 11,731 | 7,250 | 42,156 |
| 1982 | 13,003 | N/A | 4,786 | 2,380 | 20,169 |
| 1983 | 639 | N/A | 1,205 | 3,337 | 5,181 |
| 1984 | 1,317 | N/A | 420 | 384 | 2,121 |
| 1985 | 207 | 788 | 76 | 40 | 1,111 |
| GRAND TOTAL: | 64,746 | 788 | 38,818 | 41,383 | 145,735 |
(The 1978 total is approximate; the diesel was first offered on the Seville late in the model year, and so it ended up being omitted from contemporary tallies of Cadillac engine installations, or erroneously lumped in with the gas 350, which was also an Olds V-8 of the same displacement.)
Like the ill-starred Cadillac V8-6-4 “modulated displacement” engine, the 4.3-liter V-6 was another Cadillac engine option that was doomed before it even went on sale. Diesel engines were facing tougher particulate emissions standards that would require new technology to manage — in 1985, Mercedes-Benz introduced trap oxidizer systems for diesel cars sold in California and some other Western states — but with the costly FTC settlement agreement and rapidly shrinking sales, GM was not eager to make any further investments.
On December 5, 1984, GM publicly announced that all of its passenger car diesel engines except the four-cylinder Isuzu diesel (offered in the Chevrolet Chevette) would be dropped after the 1985 model year. The Oldsmobile Delta plant ended production of the 4.3-liter diesel V-6 on April 23, 1985, and the plant was retooled to build the powerful but raucous Quad 4 engine instead.
Back in the fall of 1983, a couple of aggrieved owners of 1976 Cadillac Eldorado convertibles had sued GM, claiming that by reintroducing the Eldorado convertible, Cadillac had defrauded buyers of the 1976 model, which had been advertised as the “last” American convertible and a future collector’s item. The plaintiffs demanded that GM compensate owners for lost value (to the tune of $50 million!), arguing that the introduction of newer convertibles would make their 1976 cars less valuable because they would never be truly rare.
However, Cadillac’s regrettable diesel interlude makes clear that rarity is no guarantee of either collectability or value. Plenty of cars that have never been rare still have robust collector followings and command high prices. Cadillac diesels were built in much smaller numbers, but their values were low even as late-model used cars, and the number of people interested in one today — at any price — is very limited. There’s a YouTuber (Cary’s Garage) who has one. I found only two sales listings for 1985 De Ville diesels, and neither seller thought to offer even a single blurry underhood shot of their car’s extremely rare 4.3-liter V-6 engine.
Related Reading
Vintage Review: 1978 Cadillac Seville Diesel – Puffing And Chugging To Deadly Sin Status (by GN)
Automotive History: 1978 Oldsmobile 5.7L Diesel V8 – GM’s Deadly Sin #34 – Premature Injeculation (by Paul N)
Vintage R&T Reviews: 1978 Oldsmobile 88 and 98 Diesels – A Decent Start, But Some Questions (by Paul N)
Curbside Classic: 1978 Oldsmobile Delta 88 Diesel – In Defense of the Olds 350 Diesel V8 (by BigOldChryslers)
CC Weird Engines: Oldsmobile V5 Diesel – Grasping at Straws (by Aaron65)
Cadillac spent the 1980s putting nails in their coffin at an astonishing rate. The 4.3 V6 diesel was somewhere in the periphery of my memory, but I didn’t know it was used in Cadillacs. A Cutlass Ciera seems like a much better home for that engine.
The 4.3 may have been a decent engine, but it had 5.7 disadvantages before it was even introduced.
Am I the only person who loves the bustleback Seville? I also like the aeroback 442, so I guess there’s no accounting for taste.
Yes. You’re the only person who loves the bustleback Seville. You are correct in your guess there’s no accounting for taste. Or lack of it.
No, you are not the only person who loves the bustleback Seville. I think the design is amazing!
Well, it WAS amazingly destructive to Cadillac’s image and to any chance the Seville had of being taken seriously as an import alternative.
I completely agree that it was the wrong car at the wrong time – Caddy should have expanded on the first gen’s purpose and built a real import fighter and not put out a weird, neoclassical oddity. They were particularly offputting with a carriage roof and chrome faux luggage straps, which is an all-too-common set of dealer options. However, when you see one of these today, against the backdrop of boring CUVs and pickups, they look rather distinctive and, as my daughter would say, ‘sick’. A young guy who works at a local movie theater has one in the silver and maroon combination that Hot Wheels used on their model. It is a cool car.
Somebody on my block has a `82 Seville with the diesel. The clatter that engine produced made this car sound like a diesel locomotive idling in a freight yard or a tugboat pushing some barges down the Narrows in Brooklyn, NY. NOT a nice sound for an expensive luxury car to make. Us car guys used to call this rolling monument to tacky, bad taste the ‘Servile’.
I like the Seville from the C pillar forward, but the rear end is ghastly, plus the design significantly reduces cargo capacity it would have had it the trunk had a normal shape. The Seville’s interior is also very elegant, roomy, comfortable, and ergonomically sound. If I had to choose in 1985 between a Seville (last year of this generation) or the de Ville/Fleetwood (first year of this generation) it would be a tough choice. If I could do my best not to look at the Seville’s ugly butt whilst entering the car, I’d be much happier once I was inside the Seville, with a nice view of the wall-like dash, the flat floor that the C-bodies somehow couldn’t incorporate, and door panels and seats that looked a bit more elegant then the DeVille’s. Although I think of these two cars as similarly sized, the Seville was actually almost a foot longer (though lengthening of the de Ville in future years would eventually make the C bodies fractionally longer by 1989.
Still one of my favorite designs. Classic style.
Brian H: You can add me to that list of people who love the 1980 to 1985 Seville. And by today’s standard (ugly box SUV’s and trucks being the norm), that Seville is stunning.
I mean, so is stepping on a rake.
Aaron: You seem to feel that Cadillac going after the import brands was the correct thing to do. I totally disagree.
And you know what? I’d suggest you look at the best selling “Cadillac” today. It certainly isn’t one of the import fighters now is it? No, it’s the old school Escalade that sells the most. I don’t like it and I think it’s a joke for a Cadillac and thus why I put the ” around Cadillac above.
To this day, I firmly stand in my opinion that the worst thing Cadillac has done in decades was to chase the Germans. And I stand firm that the 1980 to 1985 Seville is one of the most stunning Cadillacs in my memory.
It wasn’t per se a matter of not going after the import brands: It was a matter of completely and arrogantly writing off the majority of the Baby Boom generation — which Cadillac effectively did, to its enormous cost. The Seville said loudly, “We don’t care about buyers under 55, we’re just going to continue to chase the Lawrence Welk crowd until we’re all in the ground,” which very nearly happened. By the late ’80s, GM had looked at the projections and was seriously considering pulling the plug on the entire brand.
The awful bustleback 1980–1985 Seville hurt Cadillac badly with everyone other than the white polyester golf pants crowd, and then the 1986–1991 Seville chased most of those buyers away as well. Cadillac lost an entire decade of credibility because Bill Mitchell and Wayne Kady browbeat Ed Kennard into signing off on this stupid neoclassical ego trip, and even when Cadillac finally made the Seville into something reasonably modern in 1992, they were still fighting off the stigma of that wasted decade.
I have seen exactly one 4.3 V6 diesel, it was in a Pontiac 6000.
That’s one more than me.
The top speed is 90 mph. I think even the Peugeot 504 diesel and the Mercedes 200 D were faster (and also fuel-efficient).
The GM diesel was one of the biggest failures of the american automotive industry.
To my understanding, the 4.3 V-6 diesel ended up being basically fine except that it wasn’t very powerful (and really not powerful enough for the heavier FWD C-body cars). However, the earlier diesel V-8 had burned SO much goodwill by then that it was really a lost cause, at least in the absence of much higher gas prices, so the V-6 diesel ended up not selling well even in the FWD A-bodies.
I would agree, by the time the 4.3L diesel went to market all the problems with the 5.7L diesel had been identified and corrected on the 4.3L diesel. The only issue with the 4.3L that I heard about was that the starter was prone to wear out a little prematurely in FWD applications, and in later years was a hard part to find. I saw a few of these engines back in the day in Chevy Celebrity’s and Olds Cutlass Ciera’s. The RWD versions in G bodies were really rare, never saw one of those. I thought the 4.3L diesel might have made a neat engine for the S-10/15 pickups, but they had the Isuzu diesel in them already.
The 4.3 diesel was also available in the C-body FWD ’85 Buick Electra, known as the Electra 430.
There were Electra 300 (3.0) and Electra 380 (3.8) models the first year of the downsize.
The 3.0 was discontinued early on due to being underpowered.
The Electra 380 later became the Electra Limited, which was the base model below the Park Avenue.
I was the fleet manager at Fanning Cadillac-Buick at the time, and ordered all of them, but only one diesel Electra as a sold unit for some poor soul…
The FWD C-Bodies both Cadillac and Buick were released in April ’84 as ’85 models to build acceptance of the downsize, having both years’ models in the showrooms at the same time.
We had a Lucite hood for the Cadillac that showcased the transverse mounted V8, and a 24″ mailer that went out, which folded open to show the amount the cars had been downsized.
The Park Avenue proved more popular at first.
So I took to ordering Electra 380s and dressed them up with aftermarket top and Vogue Tyres and wheels.
Which made great switch cars for those who could not afford the Cadillacs or Park Avenues.
We could remove most or all of the profit from the add-ons, and still get close to sticker price for the cars, which made customers feel they’d gotten great deals which they did.
Some early ’86 FWD LeSabres also had the 3.0 V6 before it was discontinued and the optional 3.8 became standard.
The Electra 430 ended up being even rarer than the De Ville 4.3: Only 411 were built for 1985.
Thank you for the production numbers.
All of my stuff from the dealership is buried in storage.
It was a Cadillac factory store from 1926 until September 30, 1971 when the Feds ended that.
It then became Bill Elsey Cadillac `71-`74, then Fanning Cadillac in `74, and we got Buick in `81 when Warren Buick formerly Broadway Buick closed up the street on Broadway & Hollywood and we became Fanning-Cadillac-Buick.
We acquired a Sterling ticket in `87, and became The Fanning Store.
It closed in 1992 as Sun Auto Group after being sold by Mr. Fanning in 1990, and was demolished in 1993.
Ending almost 7 decades of business.
I was there when GM came in and locked the door, after a year of having a GMAC babysitter oversee all the deals.
That’s interesting first-hand history. I generally like the design of the 85 Electra, mainly owing to its clean styling. Aftermarket convertible-look roof and vogue tires/wheels would completely ruin that for me. It’s interesting that those items helped sell the cars to their target audience at the time, or perhaps redirected from the Cadillac target audience.
We were blessed to have both Cadillac & Buick.
A rarity until the auto malls sprung up.
Cadillac was usually paired with Oldsmobile, but Olds was already right down the street.
But Mr. Fanning was influential in the industry.
Oddly he turned down BMW when it was offered.\o/
We got Buick in `81 after being Cadillac only since `74.
We got Sterling in `87.
I did a lot of 2 door Electras too which other dealers wouldn’t order.
The carriage tops look cooler on those because of the longer doors.
`87 was the last year for 2 door Electra Limiteds and Park Avenues.
Those were great switch cars for those who wanted Coupe de Villes.
Electra T Types were `85-`90, but only `85 offered 2 doors in addition to 4 doors.
I own four 5.7 diesels, and one 4.3fwd Olds 98. Specifically, a 1985 black Olds 98, of which I’ve seen a few here and there. I drove my 1st 5.7 diesel as a 21 year old, selling them for Parkway Motors in Montreal. I found them pleasant enuff, even tho I was commuting to work in a $250 red GTO with a 400 350hp 3 speed stick
2.5 years ago, I drove my 1981 Bonneville from San Francisco to Houston to new york, 80+ mph @ 27 mpg
I also have a 1984 Sedan DeVille Feetwood, with a 5.7. I paid $2,000 for each of them, and the Caddy may have a blown head gasket. Otherwise they all run great!!!
https://photos.app.goo.gl/WYRniBCzqcm3foLT8
There’s a glimpse of my 98 FWD Diesel in my shop, along with Corvairs & Mercedes…
https://photos.app.goo.gl/mkFEvhkZmPjkwhWf6
CORVAIRWILD@GMAIL.COM
I wonder if even one of those 40 diesel ’85 Sevilles is still around.
LOL at that Ciera/Century engine availability page. It what alternate universe was the Iron Duke “smooth and sophisticated”? Maybe it was compared to an Olds diesel…
By that point, the Iron Duke did have digital engine management and O2 sensor feedback control with electronic (throttle body) fuel injection, which was pretty bleeding edge for GM. So, “sophisticated” was not altogether inapt, despite the agricultural character of the engine itself. “Smooth,” though — I got nothin’.
My stockbroker had red Sedan de Ville. I saw it in 1990 and I did know it was unusual, but I did not know it was rare. His next Cadillac had the 4.9. I don’t know how he disposed of the 85
Back in the day in the used car price guides it was more or less the norm to see “Deduct 50% for diesel engine” on all of the GM diesel cars, though to be fair that showed up for a lot of non-GM cars too. Yes VW and Mercedes were exceptions.
The sad thing is that if the original 5.7 diesel had been as good as the 4.3, things might have turned out quite differently. And an even better outcome would have been to forgo the 5.7 altogether and just build the 4.3 in NA and in a turbocharged version. GM could have solved its CAFE and gas guzzler tax issues readily and wouldn’t have required such drastic downsizing like the did with the horrible ’86 E Body cars and the underpowered 4.1 HT gas V8, and….
My Uncle Ron had a ’85 Olds 98 with the 4.3 Diesel – he must have gotten a good one, because he kept that car until 1999 when he traded it on a Chrysler 300M. He and my aunt lived in Florida, so I don’t think the diesel bothered them on the flatlands too much.
He was much happier with the 300M
I would LOVE to find a nice and clean 1985 Cadillac Deville with the 4.3L diesel. Living in California, I would need to find one that was sold new in this state or brought into this state many years ago. If not, I would not be able to register it here. So my chances of getting one of these is less than slim-to-none.
Going back many years ago, I picked up a clean but high miles 1983 Buick Century with this engine. I drove the wheels off it for a short time and it was great. Then my nephew needed a low price car, so my brother called me asking if I had anything at the dealership I worked at. The price he was trying to be at was going to kill his chances, so my brother asked if I would sell him the diesel and I did. My nephew drove the wheels off that thing for several more years until the body was gone (living in the mid-west snow belt with salt!!!). When he sold it for scrap, that engine was still running strong.
Henry Hill’s last Cadillac was a diesel? I hope he didn’t get confused in his cocaine addled last days of freedom and put gasoline in it…
All these motors really needed is a turbocharger. Turbos are ideally suited to diesels. I assume the reason GM did not slap turbos on their diesel engines was cost. However, a turbo would probably have probably made about 110 hp with 4.3 V-6 diesel. While the cars would still have been slow, at least they were not dangerously slow.
Skeletons in the Cadillac closet that ultimately finished their’standard of the world’ persona. Sad, really.
Well said. Those who can afford a luxury vehicle don’t mind paying for it, but there has to be some level of worth, too. GM completely abandoned that in the Roger Smith era, resulting in significant long term damage to Cadillac’s reputation, which was not good for their highest-profit division. If not for GM’s monstrous size, I dare say that Cadillac would have been relegated to the luxury marque dust bin ages ago, not unlike, say, Packard.
Today, thanks largely to Mary Barra’s stewardship, Cadillac has regained much of their once shiny, hard-earned luster with vehicles that are not only high quality, but a decent value, as well (particularly in the EV segment).
Even the fully customizable, $300k Celestiq isn’t a bad alternative to other, way more pricey, ultra-luxury vehicles that command the type of cachet and prestige that’s so important to buyers at that level.
Back in the 80’s a customer had his own heavy duty diesel engine repair shop. He started taking in the Olds diesel when things got slow, and before he knew it he had all of the business he could handle. Some dealers were giving him all of their diesel business. As his reputation grew he eventually hired three more mechanics. As the auto diesel business dried up he had enough heavy duty business to keep his business running smoothly. Country boy does good!
Here’s an ’83 Ciera Brougham with the diesel I came across back in 2022… 90k+ showing on the odo, probably its only time around the dial judging by the seat fabrics. It had a large sticker on the air cleaner warning to not use starting fluid… Haven’t seen one since, or before that I can recall.
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I think the 1983 Cutlass Ciera 4.3 diesel might have been the LEAST-rare application: There were 15,180 of them for ’83, which was close to 60 percent of all 1983 4.3 diesel cars. Obviously, by GM standards, that was nothing, particularly considering Oldsmobile’s 1,600-engine-a-day capacity, but it wasn’t disastrous. If GM could have continued selling 15K of each A-body diesel car a year, they probably would have considered it a modes success.
If I was a successful executive with teenage drivers coming of age in my family, a 4.3 diesel would be the perfect car to keep our new drivers in line.
The ’85 C-Body with the 4.3 may have the lowest net output of any postwar Cadillac, but I don’t think it was the most “underpowered.” I believe that honor would fall to the 80-85 D-Bodies with the 105hp LF9. I’ve not come across any instrumented “tests” of the big Caddies with diesels, but Motor Trend did test a number of B & C bodies between 1979 and 1981 with this powerplant and came up with the following performance stats:
5/1979 – Pontiac Bonneville Brougham: 0-60 19.1 seconds
6/1980 – Chevrolet Caprice Classic Wagon: 0-60, 19.6 seconds
1/1981 – Oldsmobile 98 Regency: 0-60, 20.0 seconds
The only test I was able to find of a FWD C-Body equipped with the LS2 was an obscure 1985 Popular Science test of domestic luxury cars, where the C-bodies were pitted against a K-Body New Yorker and a Continental. An Olds 98 equipped with the 4.3 did 0-60 in 18.4 seconds.
This sounds about right, as earlier tests of Oldsmobile Cutlass Cieras equipped with the LT7, 3-speed and 2.39 final drive came up with 0-60 times in the 15 second range.
MT, 7/1982 – Cutlass Ciera LS: 0-60, 15.41 seconds
CD, 8/1982 – Cutlass Ciera LS: 0-60, 15.50 seconds
MT 9/1983 – Cutlass Ciera ES: 0-60, 13.47. seconds
The FWD C-bodies undoubtedly weighed considerably more than the A’s, but they also had the advantage of routing power to the pavement through the 440-T4 and 2.84 final drive, which I’m sure helped some. 0-60 in 17-18 seconds sounds about right.
The LF9 diesel V-8 wasn’t available in the Fleetwood Limousine, which used the 368 until 1985. The limousines were not subject to the gas guzzler tax because their GVWR was over 6,000 lb, their fuel economy was going to be poor either way, and they were sold in such small numbers that their CAFE impact was minimal.
For rarity, I’d much prefer a base Chevy 2 with no options and the 153 cubic inch engine. Or maybe a 3rd gen Camarbird with the Iron Duke.