Six-cylinder engines have existed for over a hundred years and have played a vital role in the automotive world for nearly that entire time.
BMW, in particular, has a deep appreciation for the inline-six configuration not just for automobiles, but also in aviation.
That enthusiasm makes sense. We’ve seen six-cylinder engines powering everything from family vehicles to high-performance sports cars and rugged work trucks.
Their ability to adapt to various vehicle types has helped establish the six-cylinder engine as a staple choice for numerous automotive manufacturers over the decades.
These engines also strike a solid balance between the smaller, more fuel-efficient four-cylinder and the larger, more powerful, but fuel-hungry eight-cylinder engines.
While the automotive industry is shifting towards smaller engines, hybrids, and electric vehicles to meet fuel economy and emissions regulations, a handful of six-cylinder engines still remain.
Once they disappear, it will mark the end of a truly remarkable chapter in automotive history.
With that in mind, let’s take a closer look at some of the greatest six-cylinder engines ever built. As with any engine category, there have been some excellent powerplants and some notable failures.
V6 Engines That Last 300k mi
However, the six-cylinder engines that proved to be exceptionally reliable not only satisfied their owners for years, but also played a crucial role in elevating the status of their respective manufacturers.
The modern automotive landscape would look very different had these engines never been produced.
Additionally, the most dependable six-cylinder engines often powered some of the most legendary vehicles ever made. These are the most reliable ones we were able to uncover.
Jeep 4.0 Inline-Six
Modern Jeeps are built to a high standard, but the Jeep 4.0 inline-six engine stands out as one of the all-time greats.
Produced from 1986 through the 2006 model year, this engine enjoyed an impressively long production run.
There are numerous accounts online of these engines lasting beyond 300,000 miles, with many others comfortably reaching 250,000 miles with minimal fuss.
Thanks to its simple design, it was relatively easy to repair, meaning even hobbyist mechanics could keep these engines running for decades.
What adds to the 4.0’s reputation is how Jeep owners typically treat their vehicles. While it’s true that other engines have higher mileage records, the context matters.
Jeeps are often subjected to punishing conditions off-road trails, rock crawling, and heavy-duty use and this engine endured all of it admirably.
In fact, 250,000 miles of off-road abuse is arguably more demanding than 400,000 highway miles. Still, the 4.0 wasn’t flawless. Some versions had quirks, and diagnosing problems could occasionally be tricky.
Jeep used the engine in iconic models like the Wrangler, as well as in the Cherokee, Grand Cherokee, and several others throughout the 1990s.
Owners of these vehicles can attest to the 4.0’s performance and durability. Unfortunately, its successor the 3.8-liter OHV engine wasn’t as beloved.
While adequate for many, it had its own issues and lacked the low-end torque that the 4.0 delivered, something that off-road enthusiasts especially appreciated.
Ford EcoBoost 3.5-liter Cyclone
Ford makes another strong entry with the EcoBoost 3.5-liter Cyclone. While it essentially took the torch from the Ford 300, this engine officially began production in 2007 and continues to see use in a variety of Ford vehicles.
Much like Honda’s J35, there have been several iterations of this engine, and Ford has placed it in nearly every segment of its lineup, including models like the Edge, Explorer, Flex, Fusion, and F-150.
Lincoln has also used it in the MKX and MKZ, and Mazda even featured it in certain CX-9 models.The engine has proven itself to be quite reliable over time.
It’s had some recurring issues, most notably with the water pump design and its tendency to leak, partly due to where it’s situated in the engine bay. Still, as long as the water pump is maintained, these engines are known to last for many miles.
Most common problems with Ford vehicles equipped with this engine are not directly related to the engine itself, although there are a few recalls to note depending on the specific model and year.
Among modern vehicles, F-150s with this engine are considered especially dependable.
Ford has relied on this engine platform for over 15 years, bringing it close to matching the legendary longevity of the Ford 300.
The company also developed a hybrid version of the Cyclone, used notably in the 2020 Ford Explorer.
This means the V6 may continue to play a role even as Ford accelerates its electrification plans, giving it more staying power than many other six-cylinder engines.
Nissan RB26DETT
While it’s easy to overhype engines in enthusiast circles, the Nissan RB26DETT has genuinely earned its reputation for reliability. Part of Nissan’s RB engine family, it was developed and used in various forms between 1985 and 2004.
Remarkably, in 2019, Nissan even brought the RB26 inline-six back into production something very few engines ever achieve after being discontinued.
This engine was specifically engineered for the Skyline GT-R, where it truly made its mark.
Legend has it that Nissan needed an engine capable of enduring the demands of high-speed, high-boost racing but the initial efforts didn’t hold up.
That’s when Nismo, Nissan’s motorsports division, stepped in to build something that could meet those challenges.
The result was the RB26DETT, a powerful and robust engine that went on to power multiple race-winning GT-Rs in the early 1990s. Its resilience in competition translated into impressive reliability in everyday use.
However, the RB26DETT was a high-performance engine and wasn’t used in Nissan’s mainstream models. It’s easy to imagine how exciting it would have been to see a de-tuned version offered in the brand’s standard cars.
Although there were other RB-series engines, the RB26DETT is widely considered the best of the bunch.
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Toyota 2JZ-GE
It’s no surprise to see Toyota on this list, as the company is known for building some of the most durable engines ever made. The 2JZ-GE is a standout example.
Produced from 1991 to 2007, this 3.0-liter inline-six engine was a powerhouse that consistently exceeded expectations.
Toyota also developed closely related versions such as the 2JZ-GTE, which featured twin turbochargers, and the 2JZ-FSE, which came only with an automatic transmission.
The 2JZ-GE gained fame for powering the Toyota Supra in the 1990s, but it also saw use in models like the Crown, Chaser, Origin, Progres, and Altezza.
Lexus used it as well in the SC 300, GS 300, and IS 300. It earned high marks for reliability across all these applications due to exceptional engineering.
With regular maintenance, reaching 250,000 miles wasn’t just possible it was practically expected.
Another highlight of the 2JZ engine was its tunability. Performance enthusiasts regularly pushed the engine far beyond stock limits.
There are reports of modified versions producing up to 2,600 horsepower with many builds surpassing 1,000 horsepower while still retaining most original components.
This level of durability under extreme tuning conditions further proves the engine’s legendary reliability. Toyota truly created something special with the 2JZ, and it’s unfortunate that it wasn’t installed in more models.
Toyota’s Supra lineage dates back to the late 1970s, when the nameplate emerged as a slightly bulkier and more powerful version of the company’s second-generation Celica coupe.
Known then as the Celica Supra, these models were distinguished by their extended wheelbases, wider bodies, and more potent six-cylinder engines. However, at their core, they remained Celicas.
That changed in 1986 when the Supra name became independent of the Celica. By the time the fourth-generation Supra debuted in late 1992, it bore virtually no resemblance to the Celica, sharing about as much DNA with Toyota’s entry-level sport compact as it did with the quirky Paseo.
This separation was largely due to the inclusion of the factory turbocharged 2JZ-GTE engine—a robust inline-six-cylinder capable of generating astonishing horsepower figures.
Even nearly three decades later, motorsports teams across various disciplines still pursue early 1990s 3.0L 2JZ-GTEs, and for good reason. Few production engines, then or now, can handle such extreme horsepower gains with such minimal modification.
In the U.S., the 2JZ-GTE was a clean-sheet engine design, completely unrelated to the prior-generation Supra’s 7M-GTE. It was exclusively available in the 1993 to 1998 Supra Turbo models. In Japan, the 2JZ-GTE made its debut in 1991 under the hood of the Toyota Aristo and continued to power select Japanese-market Supras until the model’s discontinuation in 2002.
While the naturally aspirated 2JZ-GE variant—based on the same short block and featuring a nearly identical but higher-compression rotating assembly—is easier to find, it’s a far less desirable option. Toyota rated the 2JZ-GE at around 230 hp, which is underwhelming by comparison.
If you’re chasing true performance, avoid these versions, which you’ll typically find under the hoods of non-turbo fourth-generation Supras, as well as in the Lexus IS300, GS300, and SC300.
There are Japanese-market alternatives worth considering, like the 1JZ-GTE. This is essentially a de-stroked 2.5L version of the familiar cast-iron long block and, in its later iterations, featured variable intake cam phasing and a single turbocharger.
The 2JZ-GTE itself was updated in 1997 for the Japanese domestic market with the addition of VVT-i and refined turbos. Still, most enthusiasts in North America are more interested in the U.S.-spec 3.0L version—the one that ignited a passion for Japanese performance even before they could reach the pedals on their childhood bikes.
That said, Japanese Domestic Market (JDM) engines can be easier to source, less expensive, and just as capable, though they do come with minor drawbacks like smaller fuel injectors and different cam profiles.
Toyota’s engineers drew inspiration from Nissan’s dominant RB engine series when designing the 2JZ platform. Much like the RB26DETT, the 2JZ benefits from its inline layout, which naturally balances engine forces.
Unlike V-type engines, where rotating assemblies oppose each other and create uneven forces, the inline design features symmetry: the front three cylinders counteract the motion of the rear three.
This equal distribution eliminates the kind of polar rocking motion typical of a V6, allowing the 2JZ to rev higher, longer, and more smoothly without compromising stability or longevity.
The secret sauce behind the 2JZ’s reputation is its ability to handle double—or more—its stock power output without needing internal reinforcement.
It starts with a heavy-duty cast-iron block rather than lightweight aluminum. Then comes a solid deck design to resist cylinder movement, a forged steel crankshaft, and dished pistons to manage compression levels.
Seven main caps lock the crankshaft in place, while under-piston oil squirters keep temperatures and friction in check at high rpm. Additionally, the 2JZ was engineered with optimal geometry—specifically, a square bore and stroke ratio—making the engine especially robust and efficient across a wide rpm range.
“Aside from a temperamental bracket that secures the tensioner in place, an oil pump seal that’s notorious for pushing itself out, and a crank pulley that likes to come apart, failures don’t occur often,” according to Southern California Supra expert Ian Sai-Ngarm of FSR Motorsport Creations.
The 2JZ-GTE stands as a symbol of bulletproof engineering. Its blend of thoughtful design, proven durability, and legendary performance potential make it not only a foundational component of the Supra legacy but also a crown jewel in Toyota’s performance history.
Cummins Diesel
The Cummins diesel engine is often regarded as one of the most durable engines ever created. Introduced in 1989 in Dodge Ram trucks, it remained a popular option until 2023.
Sadly, Dodge announced that the 2024 Ram 1500 would no longer offer one key diesel engine configuration.
This is unfortunate because Ram trucks powered by Cummins diesels are nearly indestructible when maintained properly.
Prior to its phase-out, this engine was available in the Ram 2500, 3500, 4500, and 5500, and even appeared in the Nissan Titan XD.
What set this engine apart? It initially delivered 160 horsepower and an impressive 400 lb-ft of torque at just 1,600 RPM.
Later versions produced up to 325 horsepower and a whopping 600 lb-ft of torque. With that kind of muscle, it could likely tow a house if needed.
It also managed around 33 MPG on the highway an exceptional figure for a truck engine.
According to Consumer Reports, it could reliably last up to 300,000 miles, which is particularly noteworthy given the heavy-duty work it was designed to perform.
Even more impressive are stories of Cummins diesel engines reaching 600,000 miles or more with just basic upkeep and minor repairs.
While other diesel engines also offer high mileage potential, that’s the secret to the Cummins’ success.
Diesel engines generally have much greater longevity than gasoline counterparts, and it’ll be a real loss to the industry if they ever vanish completely.
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V6 Engines Fail Before 100k
Hundreds of millions of dollars go into developing new engines, backed by tens of thousands of rigorous testing hours to ensure reliability and performance.
Not every engine makes a lasting impression as good as Toyota’s 2JZ, inevitably some fail miserably.
Six-cylinder engines offer a solid middle ground between budget-friendly four-cylinder options and thirstier V8 powerplants.
They often come with the added perk of producing an exciting exhaust note. In recent years, six-cylinder engines have made a strong comeback, reminiscent of a prizefighter returning for one last shot at glory.
Ferrari’s latest sports car features a compact twin-turbo six-cylinder engine that still manages to deliver a full-throttle rush of adrenaline. Only time will tell how much punishment the 296 GTB can endure.
Due to the high cost of development, automakers often use these engines across a wide range of models, with mixed results.
The PRV V6 is a good example: it was sluggish in the DMC-12, blisteringly fast in the Venturi 400GT, and notoriously unreliable in other applications.
A well-engineered six-cylinder can be a great asset to the right vehicle. But when things go wrong, you may find yourself stranded, waiting for a tow truck thanks to one of these notoriously unreliable engines.
Porsche Boxster 986 (M96, 1996–2004)
Porsche consistently ranks among the most reliable car brands on the market. But the Boxster had a rocky beginning.
Initially dismissed by purists as a “budget” Porsche, the mid-engine sports car struggled for acceptance despite featuring a flat-six engine.
However, a bigger challenge emerged for Porsche. The switch to water-cooled M96 engines introduced serious complications.
A flaw in the casting process, unnoticed during development, led to a number of early production engines being susceptible to internal leaks.
These allowed oil and coolant to mix a combination that spells disaster for any engine. Compounding the issue, as the cars aged, another major defect surfaced: the infamous IMS bearing failure, which could lead to catastrophic engine damage.
It’s a car that really doesn’t need an introduction—yet here we are. A two-seat roadster that delivered an exceptional driving experience without making daily use a chore.
From its debut in 1996, it stood out as the clear next step up from an MX-5 in terms of power and price. Like many Porsches, the Boxster instantly carved out and owned its niche.
It was a pure sports car, unburdened by any shared components with mass-market saloons. That’s exactly what gave it such a distinctive and special feel.
Since then, it has led the way in its (albeit shrinking) segment. In essence, you can pick up virtually any Boxster built since its launch and still enjoy a car that fulfills its purpose with the same finesse and success. The one possible outlier is the four-cylinder 718, but “we’ve talked about that elsewhere.”
The Boxster marked a turning point for Porsche, which at the time was teetering on the edge. Its lineup then included the 911, 968, and 928—models that were costly to produce, particularly because they shared almost nothing with one another. On top of that, the 968 and 928 were financial drains.
So Porsche took a more streamlined approach. Sit in an early Boxster, and nearly everything ahead of the driver’s seat is shared with the 911. Porsche picked up that strategy from the VW Group: “sit in an early TT Roadster and pretty much all the mechanicals were shared with a Skoda hatchback.”
Jaguar E-Type SII (7L, 1961–1968)
There’s no denying the Jaguar E-Type was a revolutionary vehicle drop-dead gorgeous and blisteringly fast for its time.
When it debuted, it stunned both automotive enthusiasts and industry insiders alike.
Under the hood, Jaguar used the race-proven XK6 engine, derived from its motorsport legacy, to give the car genuine performance credibility.
But not all E-Types were created equal. The earliest models came with 3.8-liter straight-sixes that were said to hit 150 mph if you believed the promotional material.
Later versions upgraded to a 4.2-liter XK6 7L engine with a revised cylinder head and updated cooling. Unfortunately, these improvements came at a cost to durability.
Poor coolant selection and the use of oversized bolts contributed to block cracking issues that severely impacted long-term reliability.
The Jaguar E-Type, first unveiled to the public in 1961, continued through Series I, II, and III variants until 1975. It debuted as a two-seater fixed head coupe and also as a two-seater convertible. The convertible model, later known as the roadster, quickly became the most popular variant of Jaguar’s lineup at the time.
Its sleek styling and exceptional performance earned instant admiration from automotive enthusiasts. Enzo Ferrari famously described the E-Type as “the most beautiful car ever made.”
As time progressed, the stunning aesthetics of the Series I XKE required minor modifications to comply with bumper safety standards in the American market. In 1968, Jaguar introduced the Series II, which subtly evolved the E-Type to meet U.S. market specifications.
The Series II is distinguishable by its chrome-trimmed, open headlamps, a wrap-around rear bumper, larger front turn signals, and a wider grille that significantly enhanced engine cooling at highway speeds.
Additionally, this iteration was the first to offer factory-installed air conditioning and power steering, elevating the luxury and comfort of the driving experience without compromising the car’s spirited, performance-focused identity.
The 1970 Jaguar XKE featured here is presented in a striking red exterior with a black leather interior—an iconic color pairing that accentuates the car’s elegant and athletic form.
This particular XKE Roadster incorporates a well-executed and somewhat distinctive upgrade. It was common during the era to enhance Jaguar E-Types with American V8 engines to achieve greater performance.
Weighing roughly the same as Jaguar’s original cast-iron inline-six, small block V8s could be fitted snugly into the engine bay and positioned farther back in the chassis, creating an ideal near 50/50 weight distribution. The result was an increase in power, improved handling, and enhanced reliability—clear advantages for the driver.
With that context, it becomes evident why this solid example of an XKE now houses a lightweight and potent small block Ford V8 engine paired with a highly dependable Ford 3-speed Cruise-O-Matic transmission. A single test drive is enough to demonstrate the effectiveness and value of this powertrain swap.
The engine and transmission deliver a notably stronger performance than the factory 4.3L setup. Visually, the car’s exterior remains original with the exception of a modified power bulge in the hood, made to accommodate the elevated airbox assembly.
The interior preserves its traditional British sports car aesthetics, with the automatic shifter cleanly integrated in its factory location. This engine conversion succeeds in preserving the timeless beauty of the E-Type while simultaneously boosting its practicality, performance, and dependability.
BMW X5 330D (N57D, 2010–2015)
The BMW X5, a luxury SUV that brought the brand’s “Ultimate Driving Machine” spirit to the off-road segment, has been a staple on the road since its debut in 1999.
While the Range Rover might hold the edge off-road, BMW’s X5 wins out in build quality and road dynamics.
If you’re leaning toward a diesel-powered model, exercise caution. Specifically, second-generation X5s powered by the N57D series diesel engines are plagued by multiple issues.
These problems include failing turbos and malfunctioning fuel injectors both of which are costly repairs. Reliability concerns around this engine make it a risky choice for buyers considering the long-term.
Chrysler 300 (LH, 2005–2010)
The often-criticized LH-series V6 engine used in the Chrysler 300 can lull owners into a false sense of confidence.
Everything seems fine until it isn’t. Based on a previous 3.5-liter SOHC engine, Chrysler downsized the platform for front-wheel-drive models beginning in 1998.
In the otherwise sturdy 300C, the 2.7-liter variant produced 190 horsepower and sent power to the rear wheels.
The engine itself featured an all-aluminum construction, was interference-type, and included both electronic throttle control and variable intake geometry.
Over time, however, poor water pump seals led to coolant mixing with oil, creating sludge. This sludge buildup slowly and silently choked the engine to death, often without warning signs.
The Jaguar E-Type, first unveiled to the public in 1961, continued through Series I, II, and III variants until 1975. It debuted as a two-seater fixed head coupe and also as a two-seater convertible.
The convertible model, later known as the roadster, quickly became the most popular variant of Jaguar’s lineup at the time. Its sleek styling and exceptional performance earned instant admiration from automotive enthusiasts
. Enzo Ferrari famously described the E-Type as “the most beautiful car ever made.” As time progressed, the stunning aesthetics of the Series I XKE required minor modifications to comply with bumper safety standards in the American market. In 1968, Jaguar introduced the Series II, which subtly evolved the E-Type to meet U.S. market specifications. T
he Series II is distinguishable by its chrome-trimmed, open headlamps, a wrap-around rear bumper, larger front turn signals, and a wider grille that significantly enhanced engine cooling at highway speeds.
Additionally, this iteration was the first to offer factory-installed air conditioning and power steering, elevating the luxury and comfort of the driving experience without compromising the car’s spirited, performance-focused identity.
McLaren MP4-30/32 (RA6, 2015–2017)
In 2015, McLaren’s reunion with Honda along with Fernando Alonso’s return had F1 fans buzzing. Hopes were high that the partnership would recapture former glories.
But the excitement didn’t last. The season got off to a terrible start, and things only went downhill from there.
In that first year alone, McLaren-Honda managed only 27 points and failed to finish 14 races. Honda’s RA61H hybrid engine was drastically underpowered and riddled with reliability issues.
By the end of the 2017 season, the team had added another 25 DNFs or DNSs. A lack of pace and unrelenting mechanical failures ensured this engine earned its place as one of the most disappointing six-cylinder efforts in recent racing history.
The McLaren MP4-30, MP4-31, and MCL32, raced between the 2015 and 2017 Formula 1 seasons, were powered by Honda’s RA6 series of hybrid power units.
These engines marked Honda’s much-anticipated return to F1 as a power unit supplier, rekindling their historical partnership with McLaren. However, this second collaboration proved to be one of the most turbulent and challenging in modern F1 history, marred by technical difficulties and underperformance.
The RA6 series began with the RA615H in 2015, powering the MP4-30. It featured a 1.6-liter turbocharged V6 internal combustion engine combined with a hybrid energy recovery system (ERS), which included both a motor generator unit-kinetic (MGU-K) and motor generator unit-heat (MGU-H), recovering energy from braking and turbo heat, respectively. The total system output was estimated to be in the range of 850 to 900+ horsepower.
Despite its technical ambition, the RA615H was plagued by reliability issues and significant power deficits. The turbo and ERS systems were inefficient, and the engine’s integration into McLaren’s tightly packaged “size-zero” chassis led to chronic overheating and mechanical failures.
On top of that, energy deployment was inconsistent, leading to weak acceleration and poor top speed. McLaren’s competitiveness suffered dramatically, and the car was often more than 100 horsepower down on the front-runners.
In 2016, Honda introduced the RA616H with the MP4-31, incorporating a new layout for the compressor and turbine to improve turbo response and ERS efficiency.
The revised design slightly improved reliability and power delivery, but the engine still fell short of expectations. While McLaren advanced into the midfield, it remained far off the pace compared to teams powered by Mercedes and Ferrari engines.
ERS deployment improved marginally, but full-lap performance was still limited, particularly on high-speed circuits. By 2017, Honda had redesigned the power unit once again, introducing the RA617H to power the MCL32. T
his engine was based on a split-turbo architecture, similar to that used successfully by Mercedes, with the aim of achieving better packaging, cooling, and thermal efficiency. However, the redesign led to a fresh wave of reliability problems during pre-season and the early races.
Despite Honda gradually addressing the major issues and improving power output to around 900 horsepower by mid-season, the performance gap remained too large. Frustration grew within McLaren, especially with repeated DNFs and underwhelming results.
