Full disclosure: we've tried to cast a wide net here, naming engines from every segment, from luxury sedans to performance models, and all the major automakers. We could fill the whole list with engines that have made their way into the Toyota Camry and Honda Civic, but where's the fun in that? So with that in mind, here's our list of ten of the most reliable inline-fours ever built. Feel free to add more in the comments section below. 2010 Ford EcoBoost 2.0 Where You Will Find It: Ford Explorer, Volvo S60, Land Rover Freelander 2 Ford 2liter ecoboostFord has boasted a million miles of testing on every EcoBoost engine before they mass-produce it and ship it off to dealer lots, so the argument could be made that any EcoBoost engine is a potential million-mile motor. If we're sticking to the inline-fours, we're naming the 2.0-liter produced from 2010 to 2018 as our favorite. The engine's impressive resume, finding its way into everything from Fords and Lincolns to Land Rovers, Jaguars, and Volvos, should illustrate the incredible confidence the brand had in the engine. Toyota 22R/22RE Where You Will Find It: Toyota Hilux, Volkswagen Taro, Toyota 4Runner Toyota 22R-E engineThe Toyota R family is another engine lineup where you could throw a dart at a list and come away with something dependable. The naturally aspirated 22R and turbocharged 22RE are considered to stand among the finest engines the brand has ever produced, though, with many of the engines built in the early-1980s still kicking around today. In a thread on the r/ToyotaPickup subreddit, drivers report going well over 500,000 miles with only basic maintenance, with one driver reporting a million miles. The consensus among 22R and 22RE owners is that the engine can effectively go forever, but only with a rebuild every half-million miles or so. Toyota Dynamic Force Hybrid T24A Where You Will Find It: Toyota Tacoma, Toyota Grand Highlander, Lexus TX 500h Toyota-Crown-engineWith some hybrid engines, it may be too soon to call an all-time reliable powerplant. But Toyota's been at it on a mass-market scale since the launch of the first-gen Prius back in 1997, debuting with a 1.5-liter inline-four hybrid motor. Many newer Toyota hybrids run on the Dynamic Force family, with the straight-four T24 powerplant being one of the brand's favorites since its debut in 2021. We named this engine the most reliable Toyota powerplant for 2025, citing excellent JD Power scores and low maintenance costs. Volvo Redblock B230/B230FT Where You Will Find It: Volvo 240, Volvo 300, Volvo 740 Volvo redblockThe Volvo Redblock family is a line of slanted straight-fours named for, what else, their distinctive red-painted cast iron engine blocks. These ranged from 1.8 to 2.3 liters in displacement, and were built from 1974 to 1998. The whole Redblock family is renowned for reliability, but any backyard tuners out there should know that the 230s have been nicknamed the "weak Redblocks" because of their relatively modest power capacity. The connecting rods fall on the skinny side, at just 9mm in width. While they might not be the best choice for hotrodders, that measured approach to performance means that it's not hard to find million-mile examples of Redblock Volvos, like the 240GL nicknamed "Brian." BMW S14 Where You Will Find It: BMW E30 1987 BMW M3 engineThe thing about BMWs, it's not that they're unreliable, they're just high-maintenance. With regular servicing, a BMW E30 can last as long as almost anything on the road. But when an oil change costs $250, you see a lot of people skipping routine maintenance. You'll hear mixed opinions on the S14 engines that powered the BMW E30 through the late 1980s, with some drivers reporting you'll be lucky to break 100,000 miles, and others reporting odometers in the 600,000-mile range, according to users on Bimmer Forums. Put it this way: the S14 can be reliable, but you might not want to be its third or fourth owner, and it may be hard to find a rust-free example forty years since the engine debuted. VW EA888 1.8 Gen3 Where You Will Find It: Volkswagen Golf, Volkswagen Beetle, Audi A3 VW EngineThe Volkswagen EA888 lineup is fairly reliable across the board, but we're specifically recommending the third-gen version of the powerplant found in later Beetles and Golfs. Early EA888s are known for burning oil, owing to problems with the piston rings and gaskets. The problem can be rectified by pulling the engine, replacing the piston and connecting rod assemblies in all four cylinders, and putting the engine back in. You can save yourself a lot of hassle by simply going with a later model, as the engines built after 2012 tend to have fewer issues, featuring more reliable internal components. Chevy 2.7 TurboMax Where You Will Find It: Cadillac CT4, Chevrolet Colorado, Chevrolet Silverado TurbomaxThe 2.7 TurboMax, or General Motors L3B, can be seen as Chevy's answer to the EcoBoost, a turbocharged cast aluminum powerplant pushing everything from full-size pickups to luxury SUVs. While we've yet to see a million-mile example of the engine (it's still a relatively fresh face on the market compared to some of these entries) the GM Trucks forum is full of owners boasting of 200,000 miles and up, with minimal maintenance. Subaru EJ22 Where You Will Find It: Subaru Legacy, Subaru Outback, Subaru Impreza EJ22The whole Subaru EJ lineup is notoriously reliable, with the EJ20 often being cited as the best of the bunch. But, we never got that one here in the States. The next best thing may be the EJ22 that powered the early-90s Subaru Legacy and various late-1990s Subaru cars and SUVs. Subaru took a lot of measures to ensure longevity in these motors, and continued improving the engine year after year, coating pistons with molybdenum to reduce friction, tweaking piston weights, and adjusting minute components like piston pin offsets and piston skirt shapes, ensuring that the latest version of the engine would also be the most dependable. Hyundai Smartstream Gamma II 1.5 Where You Will Find It: Hyundai Accent, Hyundai Elantra, Kia Seltos MPIThe whole Smartstream lineup can be considered reliable from a "no news is good news" viewpoint. The engine family has had its share of recalls for things like loose bolts and excessive oil consumption, but the engine lineup doesn't suffer from any issues you might call "notorious." The 1.5-liter Gamma II is just a solid example of good engineering, with ongoing improvements year after year. The worst problem you're going to see is carbon buildup, which can be managed with some GDI fuel additives. Honda K24 Where You Will Find It: Honda Accord, Honda CR-V, Acura TSX K24We could fill this list with nothing but Honda K-Series engines if we wanted to, but if we have to pick just one, we're going with the K24. Maybe the best proof that the K24 can go the distance would be the fact that the highest-mileage Honda SUV ever built was a 2007 CR-V that crossed a million miles back in 2019. The car belonged to Joel Cram, a traveling sales agent who kept his X.com followers updated on the journey to the first million every step along the way.While we're highlighting the K24, you should consider this an endorsement for the entire K-Series lineup, especially the K20, being the 2.0-liter powerplant which powered Civics, Integras, Type Rs, and Honda Accords from 2001 to 2011.