For Just Two Years, GM Put A 39 MPG Diesel Engine In A Family Crossover And Everyone Forgot About It

In 2019, most of your favorite car publications all announced that General Motors was canceling a pair of diesel cars. The Chevrolet Equinox and GMC Terrain, perfectly cromulent family haulers, lost their diesel options for 2020. The announcement probably left most people realizing that both of these crossovers even had a diesel option to begin with. For just a couple of years, GM’s mid-size crossovers had tiny diesel engines advertised to get 39 mpg and sometimes got over 40 mpg in real-world testing. But the engine in these crossovers might have come a bit too late to make any real sense.

The story of the relationship between General Motors and diesel passenger cars is a tragic one. It’s one of perhaps a handful of instances of an automaker being simultaneously early and late to the same game. Back in the 1970s, GM bolted its Oldsmobile diesel V8 engine into basically everything with four tires and a steering wheel. However, the early iterations of these engines — which were rushed into production with numerous flaws — were shockingly unreliable. Diesel, which was supposed to be a savior in times of fuel shortages and economic downturns, quickly gained a reputation of not being worth it.

General Motors eventually fixed its issues with diesel just in time for diesel prices to spike, gas engines to get more efficient, and for the buyers of domestic vehicles to sort of just move on from the idea of diesel-powered land yachts. For over two decades after, General Motors continued diesel development efforts, but kept them relegated to heavier vehicles including pickup trucks, heavy trucks, and locomotives.

Like many stories dealing with modern diesel passenger cars, it took the likes of Volkswagen to help push GM back into the diesel car game in the United States.

America’s Short Love Affair With Diesel Cars

General Motors didn’t leave a vacuum in the diesel passenger car market in the 1980s. Volkswagen and Mercedes-Benz, along with a handful of other import brands, continued to sell diesels. More brands eliminated their diesel models over time, and soon enough Volkswagen and Mercedes had carved out a niche they had practically all to themselves. For a while, if an American wanted a mid-size sedan with a diesel engine, their only choice was to go German.

Volkswagen was particularly good at converting Americans to diesel. The firm’s Turbocharged Direct Injection engines were so efficient that Volkswagen Jetta owners bragged about getting well into the 40 mpg range with some drivers reporting above 50 mpg. Diesels back in those days also didn’t have today’s emissions equipment, so these engines reliably punched out great fuel economy numbers for hundreds of thousands of miles. Their fuel economy and reliability were good enough that you still saved money even if diesel was more expensive than gasoline.

Back when the 2008 Smart Fortwo hit the road in America, I remember Smart advertising its EPA-rated 41 highway mpg as the best gas-only fuel economy in America. That’s because the only way to get better mpg was to buy a hybrid or a diesel.

Consumers took note of this and little by little, Volkswagen’s little niche became mainstream. Volkswagen’s so-called “Clean Diesel” TDI era was remarkable. In 2009, Volkswagen reported that 81 percent of all Jetta SportWagen sales, about 40 percent of Jetta sedan sales, and 29 percent of Touareg sales were all diesel models. By July 2009, Volkswagen was claiming 26 percent of all the vehicles that went home with VW customers were diesel-powered. This momentum continued. In 2014, Volkswagen sold 95,823 TDI “Clean Diesel” cars in America, which accounted for a full 23.5 percent of Volkswagen of America’s sales that year. In other words, a quarter of Volkswagen’s U.S. sales were diesel products for several years.

Other automakers took note of this. A quarter of an entire brand’s sales is nothing to ignore. Mazda would end up spending nearly a decade trying and failing to replicate Volkswagen’s “Clean Diesel” technology. Sadly, Mazda must not have known Volkswagen wasn’t playing with a fair deck. The resulting Mazda CX-5 Skyactiv-D diesel then launched too late and with too many caveats to make it worth it.

As reported by the New York Times, General Motors noticed the success found by Volkswagen and wanted a piece of the pie. A press release from 2012 seems to reflect this:

The planned U.S. introduction of a 2.0L clean turbo diesel version of the Chevrolet Cruze next year is expected to benefit from growing interest in diesel cars, sales of which could double by mid-decade, according to market research firm Baum and Associates.

Diesel car sales, which account for 3 percent of U.S. sales today, are trending up, having jumped 35 percent in the first quarter of 2012 compared to the same period in 2011. Diesel car sales grew more than 27 percent last year, according to the Diesel Technology Forum. Baum and Associates predicts diesel to account for 6 percent of car sales by 2015

General Motors bolstered its position by noting that it sold half a million diesel cars in the rest of the world in 2011. So it thought a market was there. There was great fanfare when the Chevy Cruze Diesel launched in 2014. This was the first diesel passenger car from GM in the U.S. in 28 years and GM was now one of just two brands in America slinging compact diesel cars. Unfortunately, the Cruze Diesel launched just in time for the downfall of diesel passenger vehicles.

Doubling Down

Despite weaker-than-expected sales of the Cruze Diesel and the fallout of the world-changing Dieselgate scandal, General Motors did something unexpected. Like Mazda, it decided to double down on diesel technology.

As the Wall Street Journal reports, General Motors saw the fallout of Dieselgate as an opportunity. With Volkswagen’s absence in the diesel market, GM’s brands could fill in the void with diesel vehicles. Sure, most automakers were already focusing hard on electrification, but GM still saw demand for diesels that was now being unfulfilled. In 2016, GM confirmed incoming Chevy Cruze, Chevy Equinox, Chevy Colorado, and GMC Terrain diesels.

Still, by this time everyone knew that diesel cars had a remarkably small market. But GM had an ace up its sleeve. It already had an engine on hand from its European operations. Thomas wrote about this engine as it was bolted into the second-generation Cruze in 2017:

GM brought a new diesel variant to America. Instead of simply borrowing an engine from Fiat, the General went in-house, turning to Opel for its MDE engine, marketed by Opel as the “Whisper diesel.” Displacing 1.6 liters and serving up 137 horsepower and 240 lb.-ft. of torque, it might have been less powerful than the diesel available in the Mk1 Cruze, but it put a whole lot of focus on not sounding like a diesel.

In addition to the usual engine bay insulation, this diesel engine also got some trick noise-attenuation bits. The composite intake manifold was padded by acoustic foam, the crankshaft pulley featured an isolation mechanism to quell vibrations, and even the fuel rail got sound absorbing material around it. A diesel engine that could be felt more than heard, right in line with American priorities.

This engine was bolted into the Chevrolet Equinox and GMC Terrain in 2018, which both rode on the GM D2XX platform alongside the Cruze and Volt. Of course, in GM hierarchy, the GMC Terrain is the more premium flavor of more or less the same thing you got with an Equinox.

The spec sheets for the LH7 were unchanged in their application inside of the family crossovers. Like the Chevy Cruze TD, the whole point of the GMC Terrain diesel and the Chevrolet Equinox diesel was to save money at the pump while satiating diesel fans.

The best gas engine for fuel economy in the 2018 Chevy Equinox was the 1.5-liter four-cylinder gas engine, which got an EPA-rated 26 mpg city, 32 mpg highway, and 28 mpg combined. Tossing the diesel in there kicked the ratings up to 28 mpg city, 39 mpg highway, and 32 mpg combined.

What was it like in real life? It depends. Car and Driver tested both the Equinox diesel and the Terrain diesel and both crossovers returned stellar fuel economy:

The diesel-powered Terrain surpassed its EPA combined fuel-economy estimate by 2 mpg as driven by us (which is to say, driven harder than most people would) and outpaced its EPA highway fuel-economy figure by 1 mpg on our 75-mph highway test loop, for a stellar 39 mpg. This is no anomaly. The Terrain’s mechanical twin, the Chevrolet Equinox diesel, scored the same 34-mpg average and managed a remarkable 43 mpg on our highway test.

Consumer Reports also found great success with its testers:

The Equinox diesel we tested was in its element on the highway, where engine noise was subdued and fuel economy was an impressive 41 mpg. For our overall mpg, which combines city and highway driving, the Equinox diesel achieved 31 mpg compared with 25 mpg for the gas version. That gives it a highway range of more than 600 miles.

Unfortunately, the buff mags found that the fuel economy was pretty much the only thing worth getting excited for. Here’s Car and Driver again:

The rest of the GMC Terrain merely whelms us, the diesel powertrain included. While gasoline Terrains powered by either a 170-hp turbocharged 1.5-liter inline-four or a 252-hp turbocharged 2.0-liter use a new nine-speed automatic transmission, the diesel pairs with the older 6L45 six-speed auto. General Motors claims the diesel has so much torque to work with that more gears aren’t necessary, but that seems dubious. Although it is true that the 1.6-liter turbo-diesel four’s 240 lb-ft of torque is substantial (its 137 horsepower less so), the same engine is bolted to the newer nine-speed transmission in the Chevrolet Cruze diesel. And that combination does a better job of keeping the engine at lower revs, where it’s quieter and still makes good power.

The Terrain’s six-speed suffers from larger spacing between gear ratios relative to the nine-speed, which allows the engine to briefly rev beyond where it makes useful torque before upshifting. Acceleration suffers from a distinct stepped feel, as the engine’s thrust falls off momentarily before the transmission upshifts, at which point engine speeds drop back into the meatier part of the tachometer and thrust returns.

If this process doesn’t sound fast, it isn’t. The diesel Terrain is slower than a procrastinating sloth, reaching 60 mph in 9.7 seconds. We have yet to test a 1.5-liter Terrain, but an AWD Equinox with that engine required 8.9 seconds, while the 252-hp 2.0-liter Terrain AWD reached the same speed nearly three seconds quicker. The diesel engine also produces more classic diesel rattle than you’ll hear in the Cruze with the same engine, as that car’s nine-speed keeps the diesel’s revs lower.

Ouch. The people of Consumer Reports weren’t impressed, either. Often, buying the diesel version of a vehicle means getting upgraded capability. Yet, Consumer Reports noted that the dieselized Equinox and Terrain retained a 1,500-pound tow rating just like their gasoline counterparts.

Alright, so maybe they’re nice crossovers, at least? Well, both Consumer Reports and Car and Driver were pretty harsh. Consumer Reports said the Equinox had a roomy cabin, a comfortable ride, and user-friendly entertainment, but a “dull, cut-rate interior.” Car and Driver was a bit harder on both:

Need a handy guide for telling the difference between the GMC and its Chevy sibling? The Terrain is the blocky one, while the Equinox looks half-melted. Most of our staff prefers the Chevy. In any event, this generation of the Terrain is dimensionally smaller and significantly lighter than the previous model, which straddled the compact and mid-size segments and is now right-sized for the class.

Inside, the Terrain’s rectilinear design hides the subpar materials on the dashboard and door panels better than does the Equinox’s more ambitious, flowing look, but the uneven panel gaps are visible all the time, even in our test car’s black interior. There are plenty of cubbies and storage bins throughout, and although the front-seat cushions are a tad short for taller drivers, the back-seat cushion sits nice and high off the floor and marries to a comfortable backrest angle.

At least the magazine found that both crossovers handled family well for family cars. They both also had five seats, perfect for that small American family that hasn’t grown up into a Yukon just yet.

Unfortunately, both reviews arrived at the same conundrum. The diesel engine was a $3,890 option in the Equinox (later reduced to $2,200), which meant that a diesel Equinox had a starting price of $31,635. Meanwhile, the diesel Terrain required $32,595 of your money. The problem Car and Driver found was that at these prices, buyers were able to get loaded Honda CR-Vs, Mazda CX-5s, or Toyota RAV4 Hybrids for close to the price of a base model diesel GM crossover. Adding options could have taken your diesel crossover’s sticker price above $40,000.

Consumer Reports noted that the hits kept on coming. In 2018, diesel fuel was notably more expensive than gasoline, so the more expensive diesel engine cost more to fuel up before the fuel savings got to work. The fuel savings were further diminished by having to fill up on diesel exhaust fluid. Add it all up and Consumer Reports figured it would take a typical Equinox diesel buyer over a decade to begin saving money over just buying the gasoline version.

At the same time, GM appeared to have failed to capture the Volkswagen loyalists. The great thing about VW’s diesels was that they were mounted into cars that were relatively engaging to drive and could be modified to drive better. These crossovers were unexciting family cars.

Also a shame might be the reliability. While some people seem to be happy, others talk of repair horror stories that make you think of old British iron. Like many modern diesels, it sounds like the reliability of the emissions equipment may not be a strong suit. At any rate, GM seemingly failed to capture that market it thought still existed. It looks like the kind of person who bought a Volkswagen Touareg TDI wasn’t exactly racing to their local GMC dealership.

General Motors quietly discontinued the diesel crossover twins in 2020 after just two model years of sales. GM has never published sales numbers, but data from Baum & Associates suggested that GMC sold a grand total of 3,045 Terrain diesels in 2018. That’s a fraction of the 114,314 Terrains sold in total that year.

It appears these vehicles have depreciated pretty far in the years since. A quick search suggests that you could get one of these diesels for under $20,000 without too much of a fight.

So, this one was definitely a miss from GM. To be fair to the Detroit giant, the concept here was sound. Americans were once addicted to diesel power in passenger vehicles. There was a time when you could pay more for a car with a diesel engine but still come out on top. Unfortunately, that time was not 2018. The Chevy Equinox diesel and GMC Terrain diesel were good ideas that came about a decade too late.

(Images: Manufacturers, unless otherwise noted.)