When it comes to automotive reliability, few components are as essential as the engine. While many car owners seek dependable transportation, true enthusiasts often admire engines that endure the test of time. This article highlights ten remarkable engines known for running strong even after 20 years of use.
From American workhorses to Japanese precision, these powerplants are renowned for their durability, performance, and minimal maintenance needs. Selected for their proven longevity across various applications, these engines are more than just mechanical parts—they’re engineering triumphs. Let’s explore the legendary engines that keep going long after the odometer passes six digits.
1. Chrysler Slant-Six: The Workhorse That Refused to Quit
First launched in 1959, the Chrysler Slant-Six engine served reliably until 2000, a testament to its enduring design. Known for its unique 30-degree slanted configuration, the Slant-Six was used in over 30 models, from muscle cars to vans.
With displacements of 170, 198, and 225 cubic inches, these inline-six powered vehicles have run for decades with minimal issues. Its cast iron and aluminum versions were known for excellent cooling and unmatched durability.
Even when placed in performance or heavy-duty applications, the Slant-Six rarely failed, earning a reputation as a “run-forever” engine. Owners often boast of 300,000+ mile lifespans with only basic maintenance.
2. Ford 300 Straight-Six: Built for Abuse
Used from 1964 to 1996, the Ford 300 inline-six is another icon of longevity, especially in commercial and utility vehicles. Debuting in the F-Series trucks, the 4.9-liter motor was designed to handle abuse, powering everything from heavy-duty trucks to industrial equipment.
Its simple, robust construction and forged internals allowed it to endure extreme loads, and it became famous for operating under poor maintenance conditions.
Even low oil levels or overheating rarely stopped it. Stories abound of these engines outlasting the bodies of the trucks they were in. Today, many still run in classic pickups and farm equipment, decades later.
3. Mercedes-Benz OM617: The Million-Mile Diesel
The Mercedes-Benz OM617 diesel engine, built from 1974 to 1991, earned global respect for its bulletproof reliability. This five-cylinder, 3.0-liter engine was known for powering taxis and sedans for over 500,000 miles without rebuilds.
With a cast iron block, chain-driven camshaft, and diesel toughness, it was the backbone of Mercedes’s reliability reputation in the ‘80s. The OM617 was also the world’s first turbodiesel in a production sedan, combining efficiency with resilience.
Even in rough conditions, it ran smoothly for decades. For anyone seeking a diesel engine with unmatched endurance, the OM617 remains one of the best ever produced.
4. Toyota UZ Series: V8 Reliability Redefined
Toyota’s UZ engine family, spanning from 1989 to 2013, powered everything from Lexus sedans to SUVs like the Land Cruiser. With displacements of 4.0L (1UZ), 4.3L (3UZ), and 4.7L (2UZ), these V8s offered a perfect mix of power, refinement, and reliability.
The engines were so overbuilt that they found use in marine and aviation applications. Tuners, racers, and daily drivers all praised the UZ series for its long life, often running well past 300,000 miles with only routine service.
Their modular design and low-stress operation made them ideal for anyone wanting high performance without sacrificing dependability.
5. BMW M50: German Engineering at Its Best
Produced from 1990 to 1996, the BMW M50 inline-six engine helped define the brand’s reputation for smooth, powerful motors. With displacements from 2.0 to 2.5 liters, the M50 introduced variable valve timing (VANOS) and was used in the E34 5-Series and E36 3-Series.
What makes this engine legendary is not just its performance, but its robustness. The cast iron block and solid internals made it a favorite for forced induction projects, often handling significant boost with stock internals.
Even 30 years later, enthusiasts regularly find M50 engines running strong in daily drivers, drift cars, and even racing applications.
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6. Toyota JZ Series: The Indestructible Inline-Six
The 1JZ and 2JZ engines, produced between 1990 and 2007, are arguably Toyota’s most legendary inline-sixes. Found in the Supra, Aristo, and other performance cars, these engines were famed for their strength under pressure.
The 2JZ, in particular, with its cast iron block and forged internals, could handle over 1,000 horsepower in built form—and hundreds of thousands of miles in stock trim.
These engines became tuner icons and are still a benchmark for aftermarket performance. Even after two decades, they remain popular for engine swaps, thanks to their reliability, smooth power delivery, and resistance to wear and tear.
7. Volkswagen ABF: Euro Engineering That Lasts
Volkswagen’s ABF 2.0-liter 16-valve engine, produced from 1992 to 1999, was a high-revving, naturally aspirated inline-four used in the Golf GTI and Passat. Though relatively short-lived in production, it gained cult status for its reliability and performance.
The cast iron block and aluminum head allowed it to withstand aggressive driving, and it routinely reached 250,000 miles with minimal issues. While some sensors, like the throttle position sensor, were weak points, the engine itself was incredibly durable.
Today, the ABF remains a favorite for engine swaps in classic VWs and is still considered one of the best four-cylinders of its era.
8. GM LS V8: America’s Most Swappable Powerplant
Since its debut in 1997, the GM LS V8 engine family has become the gold standard in affordable, reliable power. Found in everything from Corvettes to Silverados, LS engines are known for their strength, simplicity, and versatility.
Available in displacements from 4.8 to 7.0 liters, and with outputs from 255 to over 700 horsepower, the LS platform is used in drag racing, hot rods, and daily drivers alike.
Thanks to excellent aftermarket support and durable construction, LS engines often run well past 200,000 miles. With proper maintenance, many still perform like new after two decades or more on the road.
9. Honda K-Series: High-Revving and Long-Lasting
The Honda K-Series, introduced in 2001, continues to be one of the most popular and reliable four-cylinder engines. Found in Civics, Accords, Integras, and CR-Vs, the K20 and K24 variants are known for their VTEC-enhanced power delivery and high-revving capability.
These engines thrive on spirited driving and routinely exceed 250,000 miles with little more than regular oil changes. Their strong bottom ends also make them ideal for turbocharging, often holding up under boost without internal modifications.
From daily commuting to track days, the K-Series has proven itself as one of the most dependable performance engines of the modern era.
10. Toyota 2GR V6: Modern Marvel With Old-School Durability
Toyota’s 2GR engine, a 3.5-liter V6 introduced in 2005, powers a wide range of models from Camrys and Avalons to the Lexus RX and Lotus Evora. With all-aluminum construction, dual VVT-i, and available direct injection (FSE variant), this engine delivers both performance and reliability.
Outputs range from 237 to over 300 horsepower, yet the 2GR is renowned for its low failure rates. It’s been on Ward’s 10 Best Engines list and is widely praised for lasting over 300,000 miles. Its widespread use globally ensures parts availability and maintenance familiarity, making it a top choice for long-lasting power.
From diesel workhorses to performance legends, the engines on this list have proven one thing: excellent engineering stands the test of time. Whether it’s the unstoppable torque of a Ford 300 or the race-bred refinement of a Toyota UZ, these engines share a common trait—unmatched reliability.
For car buyers looking for longevity or enthusiasts planning engine swaps, these are tried-and-true options with decades of proof. Even after 20 years, many are still in use, with some pushing double or triple that age. When properly maintained, these engines don’t just last—they thrive. These are the machines that truly never quit.
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