There is a version of this story that flatters the auto industry. Modern engines make more power from less displacement, pass stricter emissions tests than anything built thirty years ago, and can go 10,000 miles between oil changes. By nearly every spec-sheet metric, they represent a genuine engineering achievement. The problem is that spec sheets do not tell you what happens at 90,000 miles, and an uncomfortable pattern has been building for years: engines that perform brilliantly when new but start unraveling long before their predecessors would have broken a sweat.
The numbers have become hard to ignore. According to NHTSA, more than 29 million vehicles were recalled in the United States in 2024. A major focus of those recalls is engines, with over 5 million engines from five major automakers currently under recall or facing active investigations. That is not a rounding error. That is a structural problem, and understanding it means following the engineering decisions that made it possible.
The Efficiency Race Created an Endurance Problem
The core tension in modern engine design is that the goals of fuel economy and long-term durability pull in opposite directions, and for the past two decades, efficiency has been winning. Automakers facing tightening emissions regulations have responded by shrinking displacement while bolting on turbochargers to maintain power output. A 2.0-liter turbocharged four-cylinder now routinely produces numbers that would have required a 3.5-liter naturally aspirated engine a generation ago. The combustion events are more intense, the heat cycles more aggressive, and the internal stresses significantly higher.
The industry's race to downsize has created efficient and less polluting engines on paper, but fragile ones in practice. Turbos that operate almost continuously under daily driving loads wear differently than turbos designed for occasional use. Thinner oil viscosities, specified to reduce friction and improve fuel economy numbers in lab testing, leave tighter-tolerance components more vulnerable when real-world conditions deviate from ideal. Manufacturers specifying ultra-thin oil weights to meet fuel economy standards means the change serves their regulatory needs and not necessarily the customer's desire for engine longevity. These are not accidental oversights. They are deliberate trade-offs made in a regulatory environment that grades engines on what they emit and consume, not on whether they are still running cleanly at 150,000 miles.
The cylinder deactivation systems fitted to GM's V8 engines tell a similar story. Designed to improve fuel economy by shutting down half the engine's cylinders during light loads, the technology has proven deeply unreliable in practice. Problems with GM's 5.3-liter and 6.2-liter V8s, found across the Silverado, Sierra, Tahoe, Suburban, and Cadillac Escalade, often start with failing lifters associated with cylinder deactivation. When lifters fail, they can take out the camshaft, and in some cases this happens shockingly early, sometimes even before the first oil change. GM has been managing versions of this problem for over a decade without a definitive fix.
The Brands You Trusted Are Not Immune
For years, the practical advice on engine reliability was simple: buy Japanese. Toyota and Honda had built reputations over decades that functioned almost as warranties in themselves, and that advice was largely sound. It has become considerably more complicated. Toyota recalled over 100,000 trucks from the 2022 and 2023 model years with the fix being an all-new engine, and later expanded the recall to 2024 models, which suggests the underlying issue was not fully resolved. The same engine is also used in models like the Lexus LX and GX. For a brand that built its global identity on longevity, this is a significant credibility event.
Honda has not escaped either. Nearly a quarter of a million Honda V6 engines have been recalled for engine failure, with another 1.4 million engines added to the recall following an NHTSA investigation. Hyundai and Kia, which had been climbing reliability rankings steadily, face what may be the largest engine failure crisis in recent automotive history. Since 2011, close to 10 million Hyundai and Kia vehicles have been recalled due to widespread failures in their 2.0-liter and 2.4-liter engines, with hundreds of thousands of engines replaced and Hyundai potentially paying out over $5 billion as a result.
The J.D. Power Vehicle Dependability data reflects all of this in aggregate. The most recent study recorded an average of 204 problems per 100 vehicles, the highest figure recorded since the study was redesigned in its present form in 2022. Vehicle complexity has grown faster than vehicle durability, and consumers are absorbing the gap.
What Surviving Engines Have in Common
Against this backdrop, the engines that hold up well share a notably consistent set of characteristics. They tend to be naturally aspirated or conservatively turbocharged. They prioritize robust oiling systems over marginal friction reductions. They are not asked to do too much with too little. In the 2025 iSeeCars study, the Toyota 4Runner had a 32.9% chance of reaching 250,000 miles or more, which is 6.5 times greater than the overall average of 4.8%. Much of that durability is attributed to its 4.0-liter V6's build quality, broad torque band, and conservative compression ratio. That engine is essentially unchanged in architecture for over two decades, and it ages like something designed to age well.
The lesson is not that progress is bad or that carmakers should stop innovating. The lesson is that the metrics driving engine development have been misaligned with the interests of the people who own these cars long-term. An engine that delivers excellent fuel economy figures for three years and then requires a $6,000 repair is not a good engine. Automakers have been optimizing for the test, and we have been buying the results. Until regulatory frameworks reward durability alongside efficiency, the gap between how modern engines perform and how long they last is going to keep widening.
