TLDR: Currently and historically, American manufacturers are very good at making big power from big engines to make big cars go big fast in a straight line. When the market needs suddenly shifted in the ‘70s, American reliability and power output dropped drastically, and Japanese automakers were already there with efficient and reliable cars to fill the gap. They maintained that reputation through today, while American reliability was extremely poor for a few decades, and has stayed spotty for a long time. The European cars imported to the States have generally had a focus on luxury and innovation, leading to more expensive and less reliable vehicles as well.

Long answer:

Toyota was the first Japanese automaker to sell cars in the US in 1958 and has pretty much always had a focus on ~~over engineering~~ manufacturing their vehicles in such a way as to be exceptionally reliable. They weren’t super popular, but became known for being reliable and easy to fix and maintain. (@MargotRobbie and @LordOfTheChia both go into better detail on this engineering philosophy beneath this comment)

In 1973 OPEC put an oil embargo on the United States and other countries that supported Israel. This drove oil prices through the roof and the market shifted from wanting big, flashy, and powerful “American muscle,” to needing cars that could do better than 4 miles per gallon. In addition, the US government started requiring more and more emissions and efficiency controls on cars being sold.

American manufacturers struggled to adapt their existing platforms to be more efficient while Japanese companies like Toyota and Honda had already been building simple and efficient cars for years. When the Japanese economy started booming and more of their manufacturing was moved to the States, the cost to purchase and maintain a Japanese car decreased further and led them to be even more popular.

American automakers of the time were already huge corporations with lots of complacent “old guard” executives who thought people would “buy American” just by virtue of them being American. Because they couldn’t pivot very quickly (or just didn’t want to) American cars of the time swiftly became hot garbage. Increased emissions restrictions and a lack of innovation led to underpowered, over complicated, and unreliable cars that were just as expensive, and often more expensive than their Japanese competitors.

This didn’t reeeealllly start to change until big boss dawg Lee Iacocca, then CEO of Chrysler, ordered the development of the Chrysler K Platform which released in 1981. (Incidentally, the wiki on the K car provides some good insight into your question as well: https://en.wikipedia.org/wiki/Chrysler_K_platform ) But by this time the reputation damage to American cars had already been done and “Japanese” became synonymous with economical and reliable in American culture. (Think of that scene in Back to the Future Pt. 2 where 1955 Doc is all disgusted at the "made in Japan" stuff and Marty says "all the best stuff comes from Japan!")

Another big factor is that Japanese automakers continued to produce comparatively cheap, reliable, high quality cars which solidified their good reputation while American companies remained spotty. There are some exceptions to the rule (GM’s LS and Vortec 4300 engines are widely regarded as “bulletproof.” American medium and heavy duty trucks were mostly exempt from emissions restrictions so were still high quality, etc.) but in general, you can buy any Toyota or Honda in their lineup, past or current, and sleep comfortably knowing it is probably going to last. If you’re buying American, you generally have to pay more attention to the individual reliability stats of the vehicle model and often even sub-model (different engines, transmissions, and such).

In regards to European cars, it generally doesn’t make a whole lot of economic sense for them to import cheap cars because import costs mean slimmer margins and our economy class market is just too competitive. That means they typically market themselves as luxury vehicles, and/or put themselves into a specific niche. (e.g. Volvos are the safest, Mercedes is the most luxurious and innovative, BMW offers the best driving experience, etc.) Because of that, we get fewer of the cheap, “tried and true” models from European brands and more of their fancy new stuff. Stuff that is new and fancy costs more to maintain and repair. Parts are more expensive and it can be difficult to even find someone who knows how to fix the car properly. Because European cars are more expensive and difficult to maintain, lots of people just don’t. When they don’t perform maintenance, the cars break. And when the cars break, they’re even more costly to repair. This leads to the general perception that European cars are more expensive and less reliable.

There’s also a general culture perception component as well, fair or otherwise… e.g. Americans see Germans as innovative, but with a tendency to over engineer things to a fault; Italians as passionate, but more focused on performance and aesthetics over functionality; and the Japanese as fastidious and hyper concerned with quality of reputation. These stereotypes are also applied to the goods they sell in American markets.

So at the end of it all, it really boils down to costs to purchase and maintain the vehicle, each manufacturers market niche, and the general public’s perception of the foreign culture, accurate or not. There is a general accuracy in thinking that Japanese cars are more reliable, as that is the focus of their more prominent brands, but there are always exceptions.

Thanks for coming to my LEM talk.

(edited for way too many commas and some other grammar)

In the US, there is a consumer magazine Consumer Reports. This magazine is published by a non-profit who takes no advertising dollars and pays full price for anything they review so as to avoid any appearance of bias. Every year, CR sends out a survey to all of its members (8 million+) about the cars that they own, asking specific questions about problems & repairs their cars have had over the last year. They aggregate this data and present it as reliability ratings. In the past, Japanese cars have had overwhelmingly better reliability ratings than US cars. I recall in the late 90s / early 00s US cars rarely did better than the middle value of their 5 bubble scale for overall reliability, while Japanese cars almost always got the top value. (German cars also rated highly for reliability as well, but are much more expensive in the US than Japanese imports)

The difference may no longer be as large or uniform, but this is certainly where the generalized view came from.

They're considered to be more reliable because they are. Simple as that.

I'm currently car shopping for a recent model year sub-compact crossover SUV.

I was perfectly willing to evaluate vehicles from all manufacturers. Part of my search also includes looking up the available models on JD Power reliability ratings, consumer reports, and other testing agencies, and what I'm seeing is that the US-made vehicles in this category have reliability ratings that are significantly worse than the reliability ratings for the Japanese models.

Since I don't have the money to go out and buy one of everything, I'm forced to have to accept the findings of other 3rd parties who do the evaluations.

So to answer your original question: Japanese cars actually are more reliable that US cars based on the conclusions of objective test results. There's no "considered to be" about it. It's not a matter of subjective feelings on the issue.

One reason is a specific manufacturing process known as Kaizen. Here is a quick blog I found that describes it.

I'm driving a 21yo Nissan here in Germany. No VW for me, thanks.

There is a long and very simple history here. Japan had an entirely different assembly process from the US when they started making cars and simply were at first universally more reliable than all American cars, by huge margins too, for many decades. This is not as true as it used to be but still holds in some cases and has been true for so long that it is accepted as true.

I just noticed that in general the Japanese make good quality products and they put a lot of passion into a lot of things they do. Car manufacturing included, I suppose.

My dad has a 14-year old Mitsubishi and it's had zero problems except when the brakes broke once (it was fixed easily though). It's in almost perfect condition.

Me, planning to go to the service with my almost 6 years old Honda, for the first time outside the scheduled inspections (to replace break pads) vs my friends replacing engine in a 4yo French car, and faulty suspension in a 6yo German car...

No idea... It is a mistry!

Because my japanese car is more reliable that my other cars :P

Depends somewhat on the brand, but for something like Toyota or Honda, it's because they really are just more reliable and more easily maintained on average. Nissans or Mazdas, not so much (especially Nissan).

Have a European car and a Japanese one, one is 6 yrs old, one is 8. The Japanese one has only got regular service so far with no additional work done, besides a battery change at year 4. The European one, I have changed small obscure electronic parts to rebuilding the engine head from a donor engine, that essentially cost 1/5 of the insurance value of the car. The European one rides well, is nicely tuned, but I am going all jap in my next change lol.

European car parts are also about 3 times the cost of the Korean ones, and at least double of the Japanese ones, so servicing the car in the company workshop costs about 3 times as much as servicing an Asian car (in my country). If your country has a good service network for Japanese cars, like a Toyota, Honda or Suzuki, consider them, the total cost of ownership can be much lower in my opinion. If your country doesn't have that advantage, then the point is moot.

Is that true? I'd say in the UK the most reliable brands are generally considered to be European. e.g. Volvo, VW, BMW.

The best way to get a quick understanding I think is to listen to episode 561 (2015) of This American Life about NUMMI in California:

https://www.thisamericanlife.org/561/nummi-2015

Toyota was more or less forced to start building cars in the US in the early eighties and did so in an unlikely joint venture with General Motors. GM was very interested in learning how Toyota build their cars. Bottom line: the Toyota Production System or TPS is mostly a way of management thinking that is completely different from the way most companies in the world manage people.

It is based on trusting employees, enforcing employees by training them, allowing employees to report errors as soon as possible, viewing the production proces as a manager with your own senses, understanding the production proces, truly following a vision and more.

Toyota actually does what most managers learn in management schools but don't practice. Most managers outside Toyota want to be a boss and not a leader. But Toyota wants leaders that are being followed by employees based on intrinsic values.

Interestingly, the Toyota Production System is heavily influenced by the Training Within Industry program developed by the US Army during WWII and taught in post-war Japan by the US. And statistician W. Edwards Demming who showed Japan what true PDCA looks like.

Although an initial success, the production plant ultimately stopped operating. It was purchased by Tesla, and AFAIK, as of today Teslas are being build in the same plant in Fremont. But I highly doubt TPS is used to build Teslas.

In the 70s/early 80s, smog laws meant American cars had problems. Suddenly became harder to work on, more complex, less reliable in general. Japanese cars were small tin boxes with tiny motors that didn't need as much complexity to meet those new requirements.

Good marketing.

Back in the 80s, 90s and early 00s, Japanese brands were indeed more reliable. That isn't really the case any more. Not saying they aren't reliable, but they aren't the leaps and bounds better than anyone else anymore. But the marketing for Toyota (especially) as well as Honda really leans in on the reliability angle. It is kind of like how Volvo leans heavily on safety in their marketing material. Their cars are indeed safe, but I wouldn't say they are much safer than any other similar category vehicle, but since their marketing pushes that topic so much laypersons equate them to safety.

When it comes to Japanese quality, it also really helps them that their used cars from their heyday are still around. You still see 90s era Camrys and Corollas once in a while, but not so much cars from other brands. So people see those, much more simple and thus more reliable vehicles and think modern Japanese today vehicles are way more reliable than everyone else.

The automotive press doesn't help too much in dispelling the myth either. I was looking at the results of a recent quality survey. All you hear about from these lists are the rankings, but no one ever talks about the scores themselves. You don't know if the rankings were really close or really far apart. These quality surveys list number of problems per 100 vehicles. The top ranking brands are usually around 140 or 130 problems per 100 vehicles (or 1.4 to 1.3 problems per each vehicle). In 2022 JD Power Initial Quality survey ranked Buick, Dodge and Chevy top 3 in their quality survey with Lexus down to 6th place and Toyota in 14th place.

So if you go just by the ranking, you'd think that Lexus has totally lost it in quality. Well they might have slipped a little, but when you look at the problems per vehicle, Lexus has 1.57 problems per vehicle, while the top ranking Buick brand had 1.39 prblems per vehicle. That's pretty darn close even though the ranking for Lexus is way further down the list. The industry average is 1.80 problems per vehicle so that might go to show you how the top ranking brands are not that much better than average.

I also don't think the domestic brands get the credit they deserve for their quality. They are typically right up there with the Japanese brands in terms of quality these days, but all everyone talks about is how their uncle's 1984 Camaro had a window motor issue and then an alternator problem and then a bad diff.