Diesel pickups are widely beloved today, but it wasn’t always thus. Once upon a time, the idea of a regular pickup with a diesel engine was a strange and alien idea. The Big Three would eventually start fiddling with the idea in the late 70s, but someone else got there first. That brand was International Harvester, via the Scout. Had a couple of things gone differently, the company could have dominated the space from the get-go. Instead, what follows is one of the great “what if” stories from modern automotive history.
In 1971, International Harvester released the Scout II, an updated take on the original Scout. From launch, it was sold as a two-door SUV, though the term wasn’t in vogue yet. In 1976, the Traveller and Terra were added to the lineup. The latter was a pickup body style, intended to take the place of the now-discontinued International Light Line pickup.
That same year, diesel power would become available for the Scout II. The brand had experimented with diesel engines in its other pickup lines before, but this time, it was a serious option any customer could order. In fact, International Harvester had a diesel pickup ready to go a full two years before Dodge or Chevy could offer the same.
Buy It In
You might think that International Harvester (IH) would have dropped its own diesel engine into the Scout II and called it done. However, that wasn’t the case. Several engines were selected for trials to determine which would be the best fit, including those from other automakers.
As covered by Diesel Power, the exact history is spotty, but reports and surviving test mules indicate that quite a few engines were trialed for the Scout II in the early 1970s. The Peugeot XDP-6.90 was allegedly discounted for poor fitment, while IH’s own D301 was seen as too thirsty, too ancient, and too big to do well, either. The Perkins 6.247 was also tested, but there were concerns around the supply of the then-new design. Allegedly, the Mitsubishi 6DR5 was also trialed and ruled out, though that engine would eventually show up in Dodge’s own abortive diesel truck effort.
In the end, International Harvester landed on the Chrysler-Nissan CN633. With a displacement of 198.5 cubic inches (3.3 liters), it offered similar horsepower to the other engines in the trials. It was selected on the basis that it fit better than its rivals and it was readily available. Good fuel economy and low maintenance requirements were also points in its favor. Despite the name, it was really just a Nissan SD33 that was being built in a partnership with Chrysler that would eventually dissolve. When the partnership ended, the Scout II just switched to Nissan-supplied units.
In 1976, the diesel was made available with the Scout II, including the Terra and Traveller models. An early review by Motor Trend in 1977 states it offered 92 horsepower and 137.5 pound-feet of torque. Reports suggest it was initially available with either a manual or an automatic, though brochures from 1979 suggest it could only be had with a four-speed manual gearbox later on. Indeed, those later documents also quote a lower figure of just 81 horsepower.
It wasn’t a whole lot of power, and progress in a diesel Scout II was slow. Motor Trend’s review posted a zero to 60 mph time of 39.5 seconds, and a quarter mile in 25.1, which was hilariously slow even for the Malaise Era. That’s what you get when 92 horsepower is charged with hauling around a 4110-pound truck. In part, though, that may have been due to the fact that the magazine reviewed the truck with the wide-ratio four-speed manual and the long 3.54:1 rear axle ratio. The close-ratio ‘box with the quicker 4.09:1 rear end would have been much faster, but anecdotally still probably in the 25-second range.
Ultimately, the truck had both strengths and weaknesses. The truck was celebrated for its low-down torque, but was considered poor for on-road duties. “For slugging along rough back country, climbing steep unpaved grades, or pulling stumps, the Terra diesel is just the right truck. On the highway or in traffic, performance is disappointing,” read the review. Indeed, the magazine considered the truck slow enough to put it in a drag race – up against a human runner.
In the first attempt, neither runner nor truck redlighted. The diesel screamed to its limit in 1st gear while the runner gained distance at every stride, but 225 ft down the strip he was finally overtaken. Several runs later, as the runner tired, the overtaking distance was cut down to 190 ft. This started a whole new speculation as to how well a 400-meter sprinter would do under similar conditions, but as the world’s best sprinters in this calss were tied up at the Olympics, the matter was soon dropped.
Fuel economy was decent, though, with the magazine recording 15.6 mpg on its test loop. It noted 10 mpg would be more typical for a contemporary gas truck. At prevailing gas prices, it figured on a saving of up to $475 on gas in 20,000 miles. However, given the $2,265 price tag of the diesel option, the magazine noted it would take around 95,000 miles of driving before you broke even. The magazine also noted that diesel wasn’t readily available outside of major truck stops – which made sense, given that diesel passenger cars weren’t a thing at the time.
Diesel Scouts were built in their thousands. They’re pretty rare, but there are still plenty of examples around.
International Harvester may have beaten Dodge and Chevy to the punch with a diesel pickup for the masses, but it had hit snags just like the big guys would in turn. The truck was slow, the gearing was iffy, and it wasn’t really resonating with consumers. Perhaps the main saving grace of the Scout diesel was that it didn’t suffer the same reliability problems that dogged Chevy’s first attempt.
Worse, as the end of the decade loomed, International Harvester was dealing with all kinds of problems. The company’s finances were in turmoil, workers were on strike, and investors were growing frustrated with management. But the beleaguered company had one more trick up its sleeve.
On The Precipice of Greatness
Late in 1979, with alarm bells going off upstairs, the Scout II was about to get a last hurrah. Where Chevy and Dodge were failing to win hearts with their faltering diesel programs, International Harvester had an ace up its sleeve. For 1980, the breathless SD33 would be swapped out in favor of the Nissan SD33T—the turbo version of the same engine.
Anyone who has driven a turbocharged diesel will tell you the difference is night and day. To that end, the SD33T offered 101 horsepower and 175 pound-feet of torque. Now, an additional 20 hp in a modern 300-horsepower car might not seem like a lot, but it makes a huge difference compared to the 81 horsepower quoted in the 1979 brochure. That’s an increase of 25%!
The additional power meant the engine didn’t have to work so hard, and that netted further benefits to fuel economy. Advertisements quoted EPA figures of 22 mpg, or 24 mpg on the highway. These were truly stellar figures compared to gas trucks of the era, and a cut above rival diesel trucks, too.
Four Wheeler reviewed the new diesel donk in 1980, and noted the significant improvement the turbo brought to the table:
In 1978, we tested the old diesel six and found the highway performance nothing short of embarassing. On a steep grade along State Highway 101 to Northern California, the old diesel dropped speed from 55 like someone had thrown out an anchor. By the time we crested the hill the rig was doing 25 mph, floored in second gear! Even the 18-wheelers were passing us.
Naturally, we had to take the turbocharged diesel over the exact same route just to remain humble. All humble aside, the new IH mill held a steady 55 mph, and just short of the crest we put the pedal to the metal and passed just about every car on the road.
The magazine also noted the engine’s good fuel economy. The truck reportedly returned over 22 mpg on the road, and 18 mpg in off-road use.
What would be truly interesting is to know how the turbodiesel Scout compared directly to its rivals. It had the benefit of forced induction, but it was also rocking a much smaller engine. Dodge had a 4.0-liter Mitsubishi straight-six making 105 horsepower and 169 pound-feet of torque. Chevy’s Oldsmobile diesel engine was a hefty 5.7-liter V8 putting out 105 hp and 205 pound-feet of torque once it was detuned for more reliability. The 3.3-liter Nissan engine in the Scout, even with the turbo, was down on power to both, and only slightly ahead of the Dodge on torque. The turbo probably helped the torque curve and drivability a lot, but on paper, the Nissan engine wasn’t definitively ahead.
Close But No Paradigm Shift
In and of itself, the numbers aren’t enough to say that the Scout nailed the diesel truck outright. But I reckon International Harvester got pretty close. All the ingredients were there: good fuel economy, low down torque, and more top-end power courtesy of boost. A few more years to perfect the formula, and it could have really been something.
In any case, the turbo model was much more popular than the previous diesel Scout. According to Diesel World, International Harvester saw a spike of 1,600 diesel sales in the first year, which then tapered off. However, when the turbo hit in 1980, they sold 5,400 examples. It could have been that the Scout was on the chopping block as International Harvester reorganized amidst corporate turmoil. Or, it could have been because people loved the turbo.
Either way, it showed that International Harvester was on to something good. Scout production ended after 1980 and the diesel went with it, but IH’s story didn’t end there. Ultimately, the company linked up with Ford to produce a line of V8s that kicked off the Blue Oval’s successful journey in the diesel truck world.
Of course, it’s common knowledge today that turbochargers and diesels are a match made in heaven. Dodge would later figure that out with Cummins power in 1989, but International Harvester was almost a full decade ahead. Maybe in another universe, we’d still be driving Scout pickups today with a whole different family of engines under the hood alongside today’s popular diesel trucks. We’ll always wonder.
Image credits: International Harvester
I had a 1980 TD Scout II for a bunch of years in the early 90’s, and loved it – it was still dog-slow, but not terrifyingly so, as the non-Turbo was(I owned a lot of Scouts, sue me) and regularly turned in 19MPG on the freeway, in a vehicle that ALWAYS got 10mpg if fitted with IH’s V-8. Since I owned a differential shop, I experimented with gear ratios and found that 3.54’s coupled with 31′ tires gave me a comfortable cruising RPM at 70mph.I upped the boost from 6-ish to about 9 pounds of boost, which helped a bit.
The motor’s Achilles heel was that it had a primitive accessory-belt drive system that was cobbled together by IH, presumably by an intern who was inexperienced with the vibrations of a diesel. It cracked the thin stamped-steel brackets that held the power-steering pump, alternator and AC compressor with regularity, and I eventually gusseted some of them, which helped the longevity. It also had a tiny alternator – like 45amps or thereabouts, since it was primarily a forklift engine and didn’t need much juice.
After 190K miles, the engine died catastrophically, and I ended up selling it to my employee and I helped him put a IH 392 into it. It’s one of the only vehicles I really regret selling as it was very clean for a Scout II and had NO RUST AT ALL, which is amazing, as anyone familiar with IH’s knows. I just got tired of not being able to source small parts and sold all my Scouts- my 800B, my ’79 Traveller, my ’80 TD – and my ’73 Travellall 4×4.
Thanks for the interesting IH content!
In 1978, I special ordered a new TERRA, 4×4, the diesel 4 speed I had driven was so much like the diesel truck I drove at work, there was no way I was driving floored all the time at the back if traffic! So I ordered a Select Edition in black with gold stripes and wheels. White cab roof. But with the 345/ 4 brl dual exhaust, with HD 727 auto,,2 speed transfer to 3:52 Detroit Locker rear, limited slip front. Awesome truck!
just watched the VGG video reviving a diesel Scout. I couldn’t see any additional videos on it, but I didn’t look too hard. It was interesting to see the Nissan motor just chugging along
diesels tend to be built stout; ones of this era were very simple mechanically and electrically, too. treat ’em right and you’ll get hundreds of thousands of miles out of them.
“Collapse” as in when the company did…or the vehicle’s structural integrity when it dissolved from rust almost immediately?
One thing the Scout is famous for, for sure.
I live in Fort Wayne, where the old plant that made the IH Scouts was at… Still see quite a good number of them on the roads here.
Is it almost a universal truth that the first to do something will fail, and those that come later will build on the idea and find success?
It’s common, huh. Handspring vs. Apple.
In the ad copy it mentions “The warranty that separates our Turbo-Diesel from the Mercedes 300SD”
Uh, because people were usually cross-shopping these two things?
If you really wanted a diesel back then, you practically did have to cross shop MB and the Scout just to get a couple of choices.
Yeah, I get that it was the only other turbodiesel but it’s quite amusing
IH had all the right stuff, just years too early. They were the first to make a “mass market” (quotes because was IH ever really mass market?) 4 door SUV in 1961, with revamp of the Travelall. They had a 3 door in 1958. They also introduced a real 4 door truck in 1961, the Travelette. And unlike anything the big 3 produced at the time for railroads or whoever, these were attractive, purposefully designed trucks, not hackjobs made by badly throwing two cabs together and using the same doors front and back.
Had IH held on to their light duty lines another 10 years, or made deals to sell their vehicles at normal car dealerships instead of tractor dealerships, they could possibly have been a real player since the 90’s. Counterpoint however, is the prototype design of the Scout III. Not really doing it for me.
That Scout III? Now THAT looks like a Lada Niva! Come at me, Adrian!
The Scout walked so others could run. The 80s Fords with the 6.9 IDI were solid work trucks, and only a little slow.
I believe International was also the first to offer a crew-cab pick-up. I’d still like to own a Travelette some day.
If only they had hung on a bit longer.
“Motor Trend’s review posted a zero to 60 mph time of 39.5 seconds, and a quarter mile in 25.1″ That can’t be correct..Those times are flipped right?
Not necessarily, it could have been doing less than 60 at the 1/4 mile. I was at a truck drag race and regular stuff was pretty slow. 30 second 1/4 and 55mph trap speed for a dump truck
Not if it didn’t get above 60mph in the quarter mile.
It didn’t get above 60 mph in the quarter mile.
That is a terrifying proposition
One rumor I’d read elsewhere about why IH’s 1980 Scout ads all featured the turbodiesel so heavily, in addition to the gas crunch, was that IH had contracted with Nissan to buy a certain minimum number of engines from Nissan and so all 1980 Scouts were built with them unless a customer ordered another engine.
That is interesting!
One of these was for sale near me for a while. Diesel, lifted, on 35’s. That one must have been SLOW! But it sure looked cool.
Will VAG stuff one of their oil-burners into the new Scout?
I hope not.
It’ll go down the road without shorts.
Does it seem weird and backward that the 1/4 time is LESS than the 0-60 time? It just looks strange and would be scary merging onto a highway.
On very slow cars, the trap speed would be less than 60, so yeah you run out of drag strip before you even get there.
I think my non turbo Jetta would have that sort of speed
It can’t be correct, just mathematically it doesn’t make sense
sure it can if it takes further than 1/4mile to reach 60mph
Buddy of mine from high school had a Terra with the turbo diesel. That thing was an absolute beast and if I could find one in good shape that I could afford to add to my fleet, I would. The biggest issue with the Scout in general was body rust. They literally turned into swiss cheese with the prevalent use of road salt in the winters. I’ve said that the Scout II Terra with the manual 4 speed and the turbo diesel are the Holy Grail of all Scouts.
The rust wasn’t just a Scout problem, it was an IH problem. I heard a story it was because IH stored their sheet metal in “buildings” that had a roof, but no walls. So rain could get on them. No idea if it’s true.
I worked with someone who bought a new 1979 Scout II (gasser not diesel), and it was getting rust-bubbles around the wheel arches after only 6 months of ownership. They didn’t last too many years in New England winters.
These are what the Rivian vehicles remind me of. They are great looking trucks.
I’m not a truck guy, but that Baja Scout Terra looks bad ass!
That wheelbase looks very short and I can’t imagine towing 10,000 pounds with it. Still, I had no idea these existed. As per usual, now I want one.
The human runner didn’t have a chance (Olympic sprinters run the 1/4 in 43-44 seconds), but a fun race would have been against a horse. Fast ones can do the quarter in the low 20s.
A pro cyclist sprinting specialist might even be able to beat it or at least come very close.
Note IH was primed to put a diesel in full size pickups just before they canceled it. For 1974 IH did a complete chassis redesign for their full size pickup line primarily so it could accept the MV 404 and MV 446 engines. Unfortunately development of that engine was delayed and it was not ready for the fall 1973 introduction. The reason that this is significant was that the 6.9 that eventually made it into Ford pickups was designed to be a drop in replacement for the MV engine series. While not a direct derivative they did share the same basic overall dimensions, bell housing pattern mount bosses to bell housing dimensions and even the water pump. Had the full size line made it a couple of more years the 6.9 would have dropped in w/o any new components.
Yeah. So close.
My heart beats faster any time I see a Scout of any variety.
It looks like a Lada Niva to me
lol
COTD
I dunno. It’s giving me some real retro Giugiaro vibes.
Very cool, as I didn’t know they offered a factory diesel. A month back I saw Scout II for sale that has a 4BT diesel / TH350 swapped in. They wanted an insane amount of money for it, especially since it wasn’t a finished project and required a ton of rust repairs, but I did think a diesel Scout could be fun – especially with a manual transmission.
You’d think if somebody went to all that trouble, they would at least have an overdrive automatic.
Indeed, especially since I believe the redline on a 4BT is like 3000rpm, maybe less. An overdrive automatic, like a 700R4, which can still work without electronics but make it more capable on the highway, does seem like a better choice.
I personally was wondering why there wasn’t something like an NV3550 5-speed manual behind it, but I suppose a TH350 is likely easier to install and cheaper to source.