The early ’80s were a grim time to be a Cadillac fan. Cadillac offered a range of different engine choices, none of them very desirable. The least-bad option was one Cadillac was so embarrassed about they actually gave you a credit for ordering it: the 4.1-liter version of the familiar Buick V-6. Here’s how the V-6 compared to its misbegotten alternatives.
This 1981 Cadillac ad is rife with unintended and bitter irony: “enjoy” was a difficult verb to apply to the prospect of “driving and owning” any of the three powertrains offered on the 1981 models.
The newly standard choice on the Eldorado and C-body De Ville and Fleetwood, optional on the Seville, was the L62 V8-6-4 Modulated Displacement engine. This was the latest fuel-injected version of the underpowered but basically decent 6.0-liter (368-cid) V-8, saddled with a very troublesome cylinder deactivation system. I’ve previously written at length about the unhappy one-year run of the V8-6-4, but suffice to say that the only people who ended up enjoying it were lawyers.
Standard on the awful bustleback Seville and optional on the others was the LF9 5.7-liter (350-cid) Oldsmobile diesel V-8. This normally aspirated diesel could return better than 20 mpg, but the best thing that could be said of its refinement was that a Cadillac was insulated enough that you didn’t have to hear much of the commotion.
The Olds diesel V-8 had also racked up a truly ghastly reliability record, spawning yet more lawsuits. The 1981 and later iterations supposedly addressed most or all of the worst flaws, but the diesel engine couldn’t outrun its bad reputation, which hurt resale values — an area where Cadillac had traditionally been very strong — and made it a risky choice from a financial standpoint, even if it could get 28 mpg on the highway.
The LC4 4.1-liter (252-cid) V-6 was a Buick engine, something Cadillac was now obliged to point out in the fine print of its brochures. It was essentially the well-known 90-degree Buick “3.8 Litre” engine with a larger cylinder bore. On RWD Cadillacs, it was paired with the new 200-4R four-speed automatic, which had an overdrive top gear. Still, even Cadillac marketing copywriters couldn’t come up with anything very nice to say about the engine itself — the brochure notes noncommittally, “The V6 engine has performance you associate with “V” design, but with two fewer cylinders than a V8.”
Other than the carbureted 6.0-liter engine in the commercial chassis, the four-barrel LC4 V-6 was now the only Cadillac engine without fuel injection (although it did have a “Computer Controlled Combustion” system with electronic spark advance and oxygen sensor feedback control). The feedback control version of the Rochester four-barrel doesn’t have the best reputation, and like a lot of engines of its vintage, its array of vacuum lines can become a headache with age, but it compared to the lawsuit-generating headaches of the V8-6-4 and diesel V-8, the V-6 was relatively painless. It was also a bit lighter, and somewhat cheaper: Ordering it entitled you to a $165 credit. It was, however, very slow.
None of the powertrains offered in these years contributed much to “the pleasures of driving”: The diesel had a grim 105 hp and 200 lb-ft of torque, making for 0 to 60 times in the realm of 20 seconds. Even when it was running on all eight cylinders, the modulated displacement V-8 boasted an uninspiring 140 hp and 265 lb-ft, needing around 12 seconds to hit 60 mph. The V-6 fell in the middle, with 125 hp and 210 lb-ft.
However, in the RWD DeVille and Fleetwood Brougham, the V-6 benefited from a shorter 3.23 axle ratio, compared to 2.41 for the V-8s — figure 0 to 60 in a bit under 15 seconds. (1981 Eldorado and Seville buyers were not so fortunate, having to settle for a compromise 2.93 axle.) These were big, heavy cars, so if you were coming from a pre-1980 car with a 425- or 500-cid engine, any of these engines felt hopelessly slow, but the V-6 was still far more spry than the sluggish diesel.
The V-6 also returned decent gas mileage. In a May 1981 Popular Mechanics owners report, owners reported an average of 17.5 mpg in town and 22 mpg on long trips, where the 6.0-liter V-8 seldom hit 20 mpg even on the highway. Owners were divided on the adequacy of its performance (one called the V-6 “a disaster”), but if you had to buy a Cadillac in 1981, you could have done a whole lot worse.
For 1982, Cadillac ditched the 6.0-liter V-8 except for limousines and commercial chassis and introduced its new aluminum block HT4100 V-8 as the new standard engine for all other models. This was initially even MORE of a reliability nightmare than the V8-6-4, and unlike the modulated displacement engine, its problems couldn’t be mitigated by disconnecting the offending system (which many 1981 V8-6-4 owners did, although doing so was dubiously legal, and potentially a federal crime for a mechanic or dealer service department).
The new V-8 was actually even less potent than the V-6, which remained available as a credit option in 1982. Both had a meager 125 hp, but the V-6 had 210 lb-ft of torque, while the V-8 could muster only 190 lb-ft, although the two engines were only 40 cc apart in displacement. The V-8 was smoother than the even-fire Buick V-6, but that was essentially its only virtue. Its 17 mpg EPA city rating was actually 1 mpg lower than the V-6, and Car and Driver‘s 1982 Eldorado V-8 test car needed more than 15 seconds to hit 60 mph.
You could still order the diesel in 1982, but interest was diminishing. The diesel V-8 was no longer standard in the Seville, but 2,380 Seville owners ordered it anyway (as a no-cost option), allowing them to offend the ear and the nose as well as the eye.
Both the Seville and these later diesel V-8s still have their defenders, but by 1982, there were less aesthetically and sensorially objectionable ways to get 27–28 highway mpg, especially for this much money.
This again left the V-6 as the closest thing to a sensible choice in the bunch. Consumer Guide recommended it as the best choice for the De Ville, noting that with the HT4100 V-8’s weak performance and mediocre mileage, “Cadillac’s engineering efforts hardly seem worth it.” For better or worse, 1982 would be the last year for the Buick V-6 under Cadillac hoods. Cadillac apparently considered shoehorning it into the Cimarron, which might have been an interesting combination, but that idea went nowhere, as did a more serious plan to create a V-6 derivative of the HT4100 V-8.
The Buick V-6 wasn’t quite as rare in these cars as people seem to think: It went into 30,441 Cadillacs in 1981, 12.1 percent of production, and 17,663 more in 1982, 7.5 percent of production. The V-6 was most common in the De Ville, and was very uncommon in the Seville.
| Model Year | C-Body De Ville/Fleetwood | Eldorado | Seville | Total |
|---|---|---|---|---|
| 1981 | 23,675 | 5,132 | 1,634 | 30,441 |
| 1982 | 13,210 | 3,433 | 1,020 | 17,663 |
Judging by the various sale listings I found, the similarity in displacement and (meager) power between the HT4100 and V-6 seems to have left some owners very confused about which engine their car actually has: I ran into several listings that claimed to have a V-6 that had actually had the 4.1-liter V-8, and the previous owner of the red 1981 Coupe de Ville thought his car had a V-8.
It’s hard to praise any of these engines in anything other than a backhanded way. That the Buick V-6 was the least embarrassing of the lot is itself a pretty damning statement: The V-6 was painfully underpowered in cars this size, and the failure of an all-new clean-sheet fuel-injected V-8 to match its performance, its fuel economy, OR its basic reliability was really just shameful. It was also a distressingly callous way to treat returning Cadillac customers and Cadillac dealers, which cost the brand an immense amount of goodwill throughout the ’80s.
Which would you choose, if you had to pick a Cadillac with one of these four engines?
Related Reading
1985 Cadillac De Ville 4.3 V-6 Diesel: The Most Underpowered Cadillac Since Before WW2 (by me)
The Cadillacs of this era just speak to such a lack of leadership. Great exterior designs on the 1975 Seville and 1977 era cars. Genuinely pioneering engineering with the big diesel and the 8/6/4 engine.
But it’s as though there wasn’t a product lead thinking about the overall piece. A turbocharged, reliable, diesel V8 could’ve been a game changer – likewise a properly working 8/6/4 V8. The product line could’ve survived a few more years with the thirsty V8s imo, but not with these engines.
Not even going to speak about the Cimarron or the FWD ones – but it seems like until you get to the 1992 Seville and the 1991 RWD Fleetwood, nobody had thought about what a client might want.
“The performance you associate with the “V” design” – this is classic!! Every time I see an early 80’s Cadillac still running (and they are still out there, if fairly rare now) I am amazed that the brittle V8s are still chugging. I keep forgetting about the V6, and have to figure that these are probably the ones I am seeing, unless they have had a heart transplant.
I have shared before how Cadillacs of this era were the last Cadillacs for two older lawyers I once worked with. For one, an 81 with the V8-6-4 was his first Cadillac, something he had dreamed about for years. Once he got there, he was disappointed and drove Hondas for the rest of his life. The other had had a few Cadillacs before, but his 84 with the 4.1 sent him into a couple of Town Cars to finish out his driving years.
You wonder what kind of person was still ordering a new Cadillac in bright lipstick red in 1981. Especially a Cadillac with a V6. Probably a 70 year old lady who wore outlandish hats and still thought of herself as a siren (and a Cadillac as the ultimate). I might kind of like this car in a more subdued (adult?) color, but this “hey look at me” red is a no-go.
Ha, I think the bright red color is the only thing that makes that car any sort of desirable for me. The sort of bright flashy color a Cadillac would have so proudly in the mid 60s.
The other colors here are all pretty meh
I suspect that the red Coupe de Ville is not wearing its original paint (or was a special order). Cadillac did offer a bright red on the Eldorado in 1981, but it wasn’t this shade, and this car is too even for it to just be sun fade. The auction listing unfortunately didn’t include the tag with the trim code.
I think there’s a fair likelihood that some people ended up buying the V-6 in 1981 because they were wary of the V8-6-4, either because they’d already heard stories or because they just looked at it and thought it was too complicated to be trustworthy.
The fact that the Buick V-6 was superior to the Cadillac V-8 speaks volumes about the state of Cadillac at the turn of the 1980s. Between controversial styling on some models, reliability disasters on the V8s and diesels, it looks like they did everything they could to make customers abandon the brand.
I understand the need of having a V8 in the lineup, but rather than rushing the HT engine, in hindsight putting a Chevy 305 at least for 1982 would have been the best option; perhaps even a Crossfire unit since it had injection
Or an Olds 307, which was offered in the Olds Toronado and Buick Riviera as well as the B-body station wagons.
In hindsight, the 4.1-liter V-6 Would have been a great engine for the downsized FWD Cadillacs that would sully Cadillac showrooms during the mid and late Eighties. I guess GM had to somehow differentiate Cadillac from Electras and Ninety Eights.
Would a 4.1 V6 really have been that quick? Around 15 seconds seems kind of optimistic to me. Consumer Guide has mention of a 1981 Fleetwood, and they clocked 0-60 in 22.6 seconds. However, they also erroneously mention it had a 3-speed automatic and a 2.41:1 axle. And a 4250 lb weight. Isn’t that a bit heavy for the V6?
They also mention an ’81 Electra, coming in at 18.3 seconds. They also list a 3-speed automatic (wasn’t the 4-speed standard with the 4.1, in all the C-bodies?) and a 2.93:1 axle. They have it listed at 3,865 lb.
Here’s where I found this information… https://blog.consumerguide.com/the-10-slowest-cars-of-1981/
Consumer Guide tested a 1985 Fleetwood Brougham, with the 4.1 V8. By that time, it was up to 135 hp/200 ft-lb, in the RWD cars at least. I think it was still 125 hp/195 ft-lb in everything else. It managed to move its 4,034 heft from 0-60 in 14.8 seconds, with a 3.42:1 axle.
The Buick 252 V6 actually performed pretty well, against those under-sized V8’s of the era (Olds 260, Pontiac 265, Chevy 267), and in midsized cars wasn’t bad.
I’ve also heard the Buick 252 was pretty fragile. The 231 itself was pretty bad in those days (it didn’t get its quality reputation until 1985, when it was extensively overhauled). So boring out an already weak block, probably made it even worse!
Consumer Guide and Consumer Reports numbers are not necessarily comparable to the kind of times that the car magazines would get. I’m extrapolating from the Car and Driver figures for the diesel and the initial HT4100.
As for the weight, the Consumer Guide new car guides typically just listed the manufacturer’s base curb weight, which was without optional equipment. Motor Trend frequently did that too; Car and Driver generally actually weighed the cars, and Consumer Reports mostly did as well. So, different combinations of engine or features could make a significant difference.
Never heard of the 252 V6 being fragile, not particularly refined perhaps but it was solid as were the pre-3800 versions as far as I know. I’d certainly take one over any of the small V8s. A 307 Olds with the right axle ratio would have been a better choice than any of the stock offerings, an Olds 350 better yet.
The 1982 CDV in the second-last picture was somebody’s very special project: the front clip and (I think) the side moldings are from a 1991, and the auction ad says there’s a 1991 digital dash as well. If I had gone to all that trouble, I would have upgraded the powertrain too.
Yeah, the white car has special paint and and air suspension and all sorts of other modifications. However, 1982 cars with the V-6 aren’t abundant these days, and the fact that both the V-8 and the V-6 were 4.1 liters ends up revealing that a lot of people aren’t clear on the difference. (There was an aggravating listing for a 1982 car that claimed it had the rare V-6, when even without reading the VIN, the air cleaner clearly says “HT 4100 Digital Fuel Injection.”)
The 368 Cadillac v8 is what you want. It still has the good old TH400 and beefy rear end. A 500 cubic inch Cadillac block bolts right in, motor mounts are the same. With headers, high compression pistons and a couple of other tricks you can make 350hp/500ft-lb torque at the rear wheels. That will move these boats down the road at a decent clip
I’ll never understand why the HT4100 came out so small (in displacement) and weak, given that Cadillac knew ti was going into these large and heavy RWD cars for some years before the FWD cars came along. It needed to have been at least 4.5 L and with at least 150 or more hp. The HT4100 in these big cars was a cruel joke.
Probably to get it through the EPA emissions and CAFE tests. Automakers (especially those who made mostly large and heavy cars) were scrambling in those days to meet ever increasing standards.
Having been in sales with a Cadillac dealer from 1988 to 1995 and again from 2007 till 2014, I have some experience with these from my first run at the dealer. You talked about the confusion and I can see where that would happen being both 4.1L V6 and a 4.1L V8. The badges were different, but the average person wouldn’t realize that. I even had some confusion on which 4.1L it was. At one point, I was able to drive a Fleetwood with the V6 for a while and although not much power, it was also non-offensive and would get ok MPG.
At the end of this you ask us which engine would we choose. For me that’s easy. The 5.7L Diesel V8. Having grown up on a farm in the midwest, the diesel was a common sight and being from the 1981 to 1985 years, it was much better than the 1978 to 1980. Plus, there’s just something special about driving one of these huge cars down the road while getting around 30 MPG. I’ve owned a couple of big GM cars with that diesel and could get between 28 and 32 all the time.
“Cadillac apparently considered shoehorning it into the Cimarron, which might have been an interesting combination…”
Wasn’t the whole point of developing the Chevy 2.8 V6 that the Buick V6 block was too big externally for FWD compact applications? Certainly, Cadillac should’ve waited until it was available in the J platform and used the time to make it more of A Cadillac, which was what GM corporate brass wanted them to do but division execs wanted to be in the segment with a minimum acceptable product ASAP, even if it ended up with the early model being more minimum than acceptable and never quite recovering.
The 90 degree Buick V6 eventually found it’s way into the smaller front drives anyway.
If ya could only go back in time and tell them “The computer power just ain’t there for what you’re trying to do, and is won’t be there for 20 more years. Also the HT 4100 will need at least another year of testing and R&D. Take your lumps, pay the gas guzzler tax — Cadillac buyers won’t sweat it– and keep using the 368.”
“Thank you so much for this sage advice. Anything you can offer on the new products coming in 1986?”
‘You don’t want to know…”
Which engine would I pick? Is “none of the above” an option? If you forced me to pick, I’d take the Diesel. I think all the Oldsmobile V-8 used a common (or similar) block, so I’d take that Diesel, drive it until the engine died, and re-power it with an Olds 455.
Caddy should have kept the Olds 403 around, adapt tbi to it, cam it for low end torque and give it tall gears.
The diesel but only if I’d known it would be truly reliable, always wanted a big V8 rwd full frame rig that would get 30mpg. But the 368 V8 for sure, it’s quite easy to disconnect, I know a guy who had 2 of them and did so, they then ran like a proper Caddy should. It’s all academic though as I don’t like any Cadillac after 1979.
It’s horrible, reading about Cadillacs of this era. Because of what they had once been, but were no longer. GM’s MBAs (Mouth Breathing Assholes?) had seemingly found somehow to economize away every ounce of what had once made Cadillac special, without a thought for what this would do in the long term. You can only take so much value out of a product before the customer notices, and either complains or takes their business elsewhere. Relying on advertising to try and sell something people don’t want to buy just made the corporation look stupid and out of touch.
Most of these engines could have been good. Whether the diesel V8, or the V8-6-4, the idea held promise, but was let down by the execution. Whether it was due to poor engineering or financial interfering, the result was a damaging blow to both Cadillac and the corporation as a whole. I have my doubts about the HT4100; there was nothing high tech about a pushrod V8 when overhead cams were already de rigeuer, and the alloy block/iron head construction made me think of the Vega fiasco, revisited. Yet Škoda got this odd metallurgy to work for them through the sixties until the eighties, so why couldn’t GM?
It seems the only viable engine Cadillac had was the Buick V6. Now, a turbocharged version of the big V6 would have given Cadillac decent performance, street cred, and a realistic boost in the image department as a purveyor of modernity and high technology.
Pity the styling was still stuck in 1964; Cadillacs used to be up to the minute, not anachronistic.
A friend whom hated driving and would always pay me to drive him to his parents home up near Parish Florida (from Fort Myers) traded in their 78 Oldsmobile 98 for an 82 Fleetwood with the horrible 4100 V8. The Regency was a great highway car with its 350. The Fleetwood was so bad that the vibration from the engine caused both outside mirrors to vibrate. I drove it once and the next time, we took my 81 Bonneville Brougham with the infamous 265! It was so much smoother.
Now, to pick an engine from this deplorable era of Cadillac- I’d choose the diesel. A neighbor bought an 82 Fleetwood diesel. I asked him about it one day in 1990. The car had close to 265,000 miles on the original engine. He knew a thing or two and told me that the reason it kept running was due to some modifications he made.
First, he increased the oil capacity by using a larger oil filter. Then an increase in the cooling via a larger radiator and of course a much better water separator and large capacity fuel filter.
This era of Cadillac is why I chose my 78.
The 425 gets about 16-17 on the highway and is far better built.
Great article. Too bad GM just kept pushing customers away.
There’s a 3/4 rearview of the featured car, that seems to have caught a Nissan Skyline GT-R R32 in the back ground, no less!
As a Danish teen I was still awed by Cadillac by the early 1980s for their style and pose, but underwhelmed by their porformance.
Jesper
I had a 3.8L V6 in a Cutlass Supreme. The engine was bullet proof with the only issue of a leaking rear seal at the 7+ year mark.
Compared to the 8-6-4 V8 and 4100HT, the 4.1L V6 would be a dream come true for a Cadillac owner. A TBI injector would have give a few more horses, but substantial boost in drivability.
Lincoln