In decades past, “diesel” and “fast” were usually incompatible. Most people bought diesel cars to save some money or maybe because they were a little weird. Back in the 1980s, Isuzu wanted to sell you a diesel car that sounded like a unicorn. The Isuzu I-Mark was a diesel, but it was supposed to be fast, quiet, economical, luxurious, and affordable all at the same time. Even cooler was the fact that this jack of all trades was a rare instance of Americans being able to get diesel power in a sporty coupe. The catch? The car wasn’t quite as novel as advertised.
It’s fascinating to see how far diesels have come. If you’ve driven a modern diesel, you’re used to engines with mountains of pulling power and, depending on configuration, even satisfying speed. Even my old Volkswagen Jetta SportWagen TDI was capable of stomping out 60 mph in 8 seconds before racing to a top speed of 130 mph. Audi used to dominate the Le Mans field with diesel-powered prototype racers. The Ford Super Duty F-250 Power Stroke I took to AirVenture this year accelerated as if it didn’t have a 6,200-pound box hanging off of its bumper.
But, wind the calendars back four decades and the state of diesel was very different. Compression ignition engines were known for their loud clatter, lethargic acceleration, and slow starting performance. Many of these engines didn’t benefit from forced induction and some of them weren’t even reliable. You bought a diesel because you wanted to save money, not because you enjoyed driving a diesel. You put up with the noise, vibration, and snail’s pace in order to cheat high gas prices.
The 1980s were a turning point for passenger vehicle and pickup truck diesel engines. Manufacturers began to develop diesels that had both power and fuel economy, giving buyers reasons to eschew spark plugs for glow plugs that weren’t just saving money. The decade would see the launch of such legends as the Cummins B Series and the International Harvester 6.9 IDI. Even General Motors cleaned itself up and launched a sturdy Oldsmobile 4.3-liter V6 diesel while Ford planted Mazda and BMW diesels in its cars.
Still, even as diesels improved, they still had a reputation for being slow and rather loud. Isuzu wanted to change that, boasting about an engine that revved as high as 5,000 RPM. In any other situation, such a notion might be hilarious.
A World Car
Automakers have long been enamored with the concept of a world car. These cars and their underlying platforms are often designed and engineered by teams on different continents working toward a common goal. Their completed project will be a car that could be sold under several different nameplates in numerous different markets, spreading essentially the same car as much around the globe as possible.
World cars are a common sight today. Automakers with international engineering teams churn out common platforms that can be used to form a variety of different cars to be sold in countless markets. For example, if you’re a Volkswagen fan, you might joke that most ICE vehicles the brand makes in the modern day are just different sizes of Golf since everything from the Audi TT to the Atlas rides on the MQB platform. These cars will also be largely the same for each market, with some smaller differences to account for regional needs or tastes.
That wasn’t the case in the 1970s. Back then, automakers, even those with an international presence, kept things local and more independent. Volkswagens were German, Dodges were American, and if a brand wanted to sell a car to a different market, it often went through the work of designing a car specifically for that audience. This led to giants like Ford and Chrysler having a glut of overlapping models sold around the world that actually didn’t share a ton of parts, adding complexity to their production.
It also led to brands under the same corporate umbrella designing and engineering similar, yet completely different models. This also resulted in some other fun oddities. The Ford Transit van has been an icon around the world for decades, but it never made it into America until Ford decided to kill off the van version of the E-Series. Now, us Yanks get to drive the same vans as our European friends do.
In 1970, General Motors realized that this madness had to stop. A world car has numerous benefits. An automaker could create perhaps endless models on just one platform and sell them all over the world. Not only would this save a ton of development money, but the automaker wouldn’t have to stock tons of similar, yet different parts for a world of different platforms. A world car would be designed to sell in America, Japan, Europe, or South America with little modification.
GM’s first small-world car development was Project 909, the T-car program. The General would gather its operations in America, Brazil, Germany, and Japan together to create a front-engine rear-drive unibody compact platform with a variety of body styles. GM wanted its T-car platform to underpin coupes, two-door sedans, four-door sedans, trucks, sedan deliveries, wagons, and hatchbacks. The T-car was designed to meet as many regional regulations as possible so the most that a brand had to do was slap some new badges on its T-car and call it a day.
As Driven To Write notes, GM was so serious about selling the T-car everywhere that it made sure the design was as “international” as possible. After all, adding a bit too much local flair might put off buyers in another country, and that would end up necessitating too many changes for that market.
The first car to be printed out of this program was the 1973 Chevrolet Chevette for GM Brazil. Other T-car variants quickly followed, including the Opel Kadett C for Germany, the Chevrolet Chevette for America, and the Saehan Bird for South Korea. T-cars made their way from Argentina to Venezuela stopping at points as far and wide as Australia and beyond. Sadly, America never got to see a T-car pickup (above), but South America did.
Over in Japan, Isuzu got its own flavor of the T-car in the form of the Isuzu Bellett Gemini, later just named the Gemini. This flavor of the Chevette formula involved a two-door coupe and a four-door sedan.
Now, despite the fact that America already got the T-car in the form of the Chevette and the Pontiac T1000, the Gemini was sent to America to be sold initially as the “Opel by Isuzu” before later being confusingly condensed down to the “Buick Opel.” Of course, in those days Opels were distributed in America through Buick dealers, but the name didn’t have to be that wild. So, this was nominally a Japanese-ish car branded as both an American and German car at the same time. Look, GM is weird.
Thankfully, this confusion came to an end in 1981 when Isuzu decided to open up its own dealer network, taking the Gemini away from Buick. Don’t worry, Buick wasn’t that worried as it now had X-cars to play with. Anyway, Isuzu set up shop with the P’up truck and the Gemini, now named the I-Mark. The I-Mark had a new face, but under the new wrapper were the same bones that underpinned the Chevette.
The Fast Diesel?
Now, as I said earlier, the GM T-car was sold in America in a handful of different forms. In theory, this might be a problem for a relatively unknown automaker like Isuzu. Why would you buy a Chevy Chevette from Isuzu when you could just buy one from Chevy?
One motivating factor Isuzu had on its side was that the I-Mark was available as a sedan or a sporty-style coupe while the Chevette was still an economical hatchback. But, Isuzu didn’t lean in on this in the way you’d expect. Instead, Isuzu really played up its new diesel engine.
Introduced in 1981, this was a 1.8-liter four-cylinder diesel (also available in the Chevette). Isuzu bragged about how this car made power all of the way up to 5,000 RPM, which was impressive for a diesel at the time. At the same time, Isuzu said that this engine started in under 3.5 seconds at zero degrees Fahrenheit and that one of its defining characteristics was its quietness and speed. Isuzu proudly proclaimed that the I-Mark Diesel was the “Fastest, Quietest, Low Priced, High Mileage Diesel Powered Car In America.”
Isuzu continued in its advertising by saying that the I-Mark diesel got 41 mpg city and that the I-Mark was the fastest diesel in America that didn’t have a turbo, supposedly accelerating better than a normal economy car. Isuzu even claimed that the engine was the quietest diesel it knew of. Isuzu then bragged about standard features including a water separator, a center console, and alloy wheels.
So, how true was all of this? I mean, it doesn’t sound like Isuzu is describing a Chevette here. Well, according to the EPA’s old testing methods, an I-Mark Diesel with a four-speed manual transmission did get 41 mpg city. A Chevette diesel with a five-speed manual got 40 mpg city. Interestingly, an I-Mark with that five-speed manual got 39 mpg city per the EPA. So, Isuzu was only technically correct and only by the narrowest of margins. Allegedly, these I-Marks also had a range of around 1,300 miles when equipped with a diesel engine.
As for performance, I neglected to tell you about the engine’s performance on purpose. The 1.8-liter Isuzu diesel four in both the Chevette and the I-Mark made all of 51 HP. That’s not a lot of power, but these cars didn’t weigh a lot. I couldn’t find exact numbers for the I-Mark, but the Chevette diesel weighed 2,210 pounds. Diesel Power Magazine found that a diesel T-car could accelerate to 60 mph in 21 seconds. That’s hilariously slow, but my old Mercedes-Benz 240D W123 took longer to hit 60 mph and my diesel Smart Fortwo from 2006 is just as slow as a more than two-decade older T-car.
From a more modern Diesel Power Magazine review:
Where’d all my horsepower go? Going from a 300hp Dodge to a hopped-up lawnmower engine is just no good at all, although the fuel gauge seems to be permanently glued on “full.” The car actually does a decent job of keeping up with traffic as long as you let the engine wind up (apparently the little 1.8L Isuzu makes power all the way up to 5,000 rpm!). The transmission that was installed feels old and clunky because it is, and there is a healthy grinding noise that accompanies the First-to-Second shift. The brakes and suspension feel as good as any new car, and we have to attribute that to the previous owner replacing the brakes, springs, tires, and steering rack. Believe it or not, there’s also enough room for a pretty big guy to drive or ride in it, although the back seat only has enough space for legless dwarves.
Honestly, we’re more than happy with the car’s acceleration, ride, and handling-we figured a 51-horsepower car would be painfully slow, but it doesn’t feel all that horrible, mostly thanks to its 2,210- pound curb weight. It’ll do 0-30 mph in about four seconds, which isn’t too bad, but it takes an agonizing 17 more seconds to “accelerate” from 30-60 mph, giving a 0-60 time of just over 20 seconds. The lesson? Stay in the city with this car. Once you’re up to speed, the car does OK-it was even able to keep above 55 mph on a six-percent grade. Another cool aspect of this car is that you can actually idle along in First gear at about 2 mph, making it perfect for stop-and-go Los Angeles traffic.
Final summation? This is a killer commuter car-just don’t ask it to do anything it wasn’t designed to do (like passing).
For a period review, the legendary John Davis got to play with one in 1982, calling it the “oriental version of the Chevrolet Chevette”:
Davis noted that the I-Mark was the cheapest imported diesel in America, but the T-car platform was already showing its age by 1982. Likewise, the interior was stuck in the ’70s like the rest of the car, but Davis said that Isuzu did manage to add some Japanese touches inside. Davis also seems to confirm some of the claims in the advertising, saying the engine started quickly and that you could almost call the acceleration “peppy.”
But then he followed it up by saying the ride and steering are “historic,” which might now be my new favorite MotorWeek sick burn. Another hilarious dig from Davis was when he mentioned that doing a quarter mile in diesel is worth doing just for the sport. In MotorWeek‘s hands, the I-Mark did the quarter in 21 seconds at 65 mph, so it seems like when new, these cars were slightly faster.
The good news came from the fact that the old-school platform meant that the I-Mark was really easy to work on. MotorWeek identified two main competitors for the I-Mark diesel and that’s VW’s old diesel hatch and the Chevette diesel. However, Davis noted that the I-Mark is longer than either car and has better standard equipment for a middle-of-the-road price.
We don’t have sales data for the I-Mark diesel, but advertisements pinned the price at “under $6,700,” or around $22,427 today. Sadly, the sales data didn’t matter that much. Much like the Oldsmobile 4.3-liter V6 diesel, the I-Mark diesel fell victim to the massacre of diesel passenger cars in the mid-1980s. Isuzu didn’t even allow the diesel to be sold until the last year of the first-generation I-Mark in 1985. Afterward, Isuzu leaned more on performance for advertising than diesel power.
Unfortunately, if you want one of these you’re in for a world of trouble. There are some still left, but the ones I’ve found are battered and worn. But hey, at least they’re dirt cheap!
[Ed note: My parents, who were often in need of a good deal when I was younger, had to quickly get a car for some reason. I think one of our vehicles died and my mom had to get to work and get me to school. Somehow we ended up at a random car dealer and they had a used I-Mark diesel with a four-speed manual like the one above. No one wanted it, which is how we ended up with it. This was not a beloved car in our household and eventually got dropped for a Ford Escort hatch. I don’t remember it being particularly quick, luxurious, or sophisticated. – MH]
Through all of this, I’m still amused that Isuzu tried to get people to buy its version of the Chevette by calling it fast. But, at least according to some, it was relatively quick for a diesel. Unfortunately, so was the Chevette diesel, so it was mostly just marketing. Still, I can’t help but love Isuzu for trying to make its Chevette seem cooler than other Chevettes.
John Davis for President!
I remember my dad having a 1980s diesel Ford Tempo growing up. Abysmally slow, blew the engine twice. That one had a Mazda diesel engine in it.
It was replaced with a 1991 diesel Jetta, all of 52 hp, again bought new.
I do remember him showing it off to my grandfather, being in the car and saying “the acceleration isn’t too bad.”
Years later when a friend of mine buys a similar ’91 Jetta, but with the Ecodiesel engine instead of the non-turbo 1.6. The Ecodiesel has a catalytic converter and a turbo, but no fuel enrichment for when it’s on boost. It’s basically a turbo as emissions device to reduce smoke, though it did add about 8 whole hp. He swapped in a tachometer and we were pretty astounded to see that 80 MPH in 5th gear was near enough 4000 RPM!
Maybe part of the reason the VW felt a bit more sprightly is because ze Germans geared them so absurdly short! The original clusters not having a tachometer, they instead just had an analog clock, which my dad used to joke was so you could count the minutes to 60 MPH. lol
The original speedo in them has hash marks to indicate when to change up to the next gear. So, basically the assumption is while accelerating, you’re wide open throttle until that gear shift mark on the speedo, then shift. There is no other way to drive these cars. haha
My only diesel was an 84 A2 Jetta with 1.6l of fury no turbo, I drove to LA once and had fun on the freeways, once got 1100km out of a tank but the accelleration was glacial at best
Joe Isuzu must be spinning in his grave right now.
We had an I-Mark diesel growing up. It was a great little car even if slow as molasses. It was much better screwed together than the Chevette.
Is it just me, or is it a shame that Cadillac never got a T-car? Leather seats, some extra sound deadening, bigger chrome grille, vinyl roof, jack the price up an extra $10,000, it would sell itself, nobody buying domestic brands back then would have known the difference, could have marketed the most fuel-efficient luxury car in America
If it makes you feel any better, there was a short-lived “personal luxury” version of the Chevette called the Leata Cabalero, which featured shrunken 1970s land yacht styling complete with upright grille, vinyl roof, and swoopy/bulgy body lines.
Leata was Idaho’s first and only automotive startup company, and while capitalizing on the personal luxury car boom and the exploding popularity of compact economy cars simultaneously was a decent enough idea, GM didn’t exactly play nice providing discounted donor cars and it was quite difficult convincing people to pay for a more expensive, heavier, slower, less efficient Chevette, so they didn’t build many of the things before going out of business.
On the plus side, one of the Leata Cabalero’s available body styles was a ute. So the author is wrong, we did actually get a T-car ute in America briefly and in small numbers! A personal compact luxury economy ute, no less!
I am familiar and weirdly want one, but they don’t seem to come up for sale too often and ask crazy money for a Chevette when they do
Yeah, I want one for the “best car ever built in Idaho” novelty alone. Any surviving ones are niche collector cars though, most likely squirreled away in eccentric private collectors’ hoards until an estate sale happens.
I guess if they’re still more expensive than a regular Chevette though, that means the upcharge when new still holds weight…
They’re almost like an American take on the Triumph Mayflower
Coincidentally to Hardigree’s coincidence, My parent had a 1st generation I-mark sedan, and got a second generation I-mark hatchback when their VW rabbit was at the end of its life, and it also was replaced by a Ford Escort hatchback, but not because they didn’t like the car, it’s just that 3 years after buying it we moved from Los Angeles to SC, and they quickly regretted skimping on the air conditioner option. At least both of ours were gas powered which surprises me now knowing how big of a cheapskate my dad was.
If you were paying 17% interest on a mortgage, you’d probably be a cheapskate too.
He was such a cheapskate he didn’t believe in mortgages / credit… For over a year he and my mom lived with his parents until he could afford to buy a house in what used to be a rough neighborhood for cash. Despite living in 4 houses since I was born, they’ve never had a mortgage, and 03 was his first car loan at 60 years old and only because I talked him into it as it was a 0.9% loan.
Coincidentally, our pal Marty, over on the Mighty Car Mods YouTube channel, has just finished the build of a Holden Gemini (the Australian variant of this car) with over 200WHP with an Isuzu long block-based engine. It looks like a real hoot!
Yes, Martin’s Gemini must be the nicest one on the planet by far. The time and labor they spent on the body and paint was impressive. This article was timely for me because it didn’t occur to me while watching MCM that the US had the same car in the Buick Opel. I was alive when the Buick Opel was around and remember seeing them but didn’t make the Gemini=Buick Opel. A bit before my time because I didn’t start reading car magazines until 1982.
You bought a diesel because you wanted to save money, not because you enjoyed driving a diesel. You put up with the noise, vibration, and snail’s pace in order to cheat high gas prices.
I wonder how much more popular these would have been had WVO been more widely known about. I’m sure many restaurants would have been very happy to have nutjobs taking the oil off their hands for free rather than paying to have it dumped in a field somewhere. Or have strip malls with diesel generators burn it on site to provide heat and electricity for those tenants.
WVO is not a direct 1:1 replacement for proper diesel fuel.
At the very least, there’s a ton of labor involved in just getting the oil.
And you’re competing with the oil-recycling mafia, err….industry. Cooking oil is a commodity, and there is a whole industry to collecting, cleaning, and re-using it. Restaurants have contracts with companies, and those companies want their oil. Restaurants want to steer clear of regulatory issuees and whackos in knit hats and flannel asking “like, hey, man, do you have any fryolator oil you want to get rid of? My Vanagon is empty”
Oil acquired, you at least have to strain it. And you need a separate tank, filters, and valve setup to integrate it to your diesel vehicle so you can start it and shut it off on actual diesel, or you may never be able to start it again.
That WVO tank needs a heater.
oh, and you’ll be fighting the buildup of glycerin on the fuel system components, too.
I guess you could use it as biodiesel feedstock, if you want to be one of those proto-unabombers and have the time, space, energy, and bootlegging gear. You might as well just make moonshine, at that point.
Back in the day, the cheapskates used heating oil.
And by the time this thing hit the U.S. market, the bloom was off the rose in several ways. GM’s diesel disaster was common talk everywhere, but also the price of diesel had risen to erase and even reverse any cost advantage. And people learns real-ass quick how much care and feeding a diesel needed (BY A GOOD MECHANIC).
No free lunch.
No it is not. But I think in mild climates it can work well enough to interest a cheapskate who otherwise would burn through a lot of diesel. Like my BIL. He had a gardening service for which he used a diesel F350. To power it he had a whole homemade biodiesel, (not WVO*) setup in the backyard based on old water heaters and an arraignment with a couple of local restaurants for the oil. He was really into it.
At first getting oil wasn’t hard, the restaurants were happy to get rid of it for free, It got harder when demand for it rose and those restaurants tried to charge him for the oil. Then came the divorce which may or may not have been triggered by the janky biodiesel project. It certainly didn’t help.
*He went through the trouble of biodiesel because of the issues you described with WVO but he did look into WVO. I think if I was a prepper I’d look into it too.
Lean into being a prepper and build yourself one of those little wood gasifier trailers like the nordic countries used during WWII
No thanks. My mom grew up in post war Sweden where those were used. They’re better than walking but not as good as a horse drawn wagon.
Having worked at a McDonald’s as management in a past life, I can confirm they’ve had a contract for at least the last 15 years. When they get vegetable oil deliveries, the vendor also picks up the used oil to recycle it, along with grease emptied fom the traps on the grills. IIRC it’s like a 35% credit. Oil deliveries were a $1200 bill every couple weeks and getting $400 back on that was huge.
I imagine that’s pretty similar with any other large franchises that have to fry anything.
I guess the corporate types got into WVO too.
“Oriental”
Wow have times changed.
Based on my grandfather’s vocabulary at the time, it could have been worse, much worse
The synth nerd in me is now forever going to refer to the chevette and it’s off shoots as TcaR-909 now.
https://en.m.wikipedia.org/wiki/Roland_TR-909
The sampling geek in me appreciates that there was an Isuzu called the Stylus.
Ha. That’s great
Look, if you can’t trust Joe Isuzu to give it to you straight, I don’t know what to tell you.