[vgeek]

An easily visible one is air intakes. Many manufacturers have shifted to plastic. Peteo-engineering has advanced a lot, but they will still get brittle and break.

Interior wise, you can look at things like fabric durability-- lower deniers can be cheaper, but will wear sooner. Springs/foam in seats are another example, but this will vary across manufacturers, models and trims.

This isn't exclusive to financial engineering manufacturers like Stellantis or Nissan, either. Toyota has had issues with simple things like rust proofing (whether intentional or not) on 1st generation Tacomas leading to massive recalls and things like plastic timing guides prone to wearing out. Ford with the wet clutches having belts submersed in oil. German cars needing body off access for rear timing chain maintenance at 80k miles. Water cooled alternators (really, VW?). All types of "why?" if you follow cars once they are 3+ years old.

It seems like there are a lot of regressions that probably result from cost cutting, while others may exist to simply drive service revenue.

[bobchadwick]

OK, I went looking for sources and found this[1]:

In the United States, the Environmental Protection Agency assumes the typical car is driven 15,000 miles (24,000 km) per year. According to the New York Times, in the 1960s and 1970s, the typical car reached its end of life around 100,000 miles (160,000 km). Due in part to manufacturing improvements, such as tighter tolerances and better anti-corrosion coatings, in 2012 the typical car was estimated to last for 200,000 miles (320,000 km) with the average car in 2024 lasting 160,545 miles according to the website Junk Car Reaper.

[1] https://en.wikipedia.org/wiki/Car_longevity#Statistics

[ethbr1]

I think you're talking about apples and oranges, as parent appeared to be cataloguing recent design defects. Which are pretty common too.

That'll influence the average reliability minimally, unless you were unlucky enough to buy one of those models.

Personally, why I'd rather get something at 120k mileage w/ 250k+ max examples on the road by that calendar date. You'll know whether they designed a lemon.

Add: undersized Tacoma rear leaf springs, multiple manufacturers' head gaskets, a few early aluminum engines (? from memory)

[vgeek]

There are many other considerations, too. Years ago I scraped Craigslist and Autotrader, grouping cars by generation/make/model/drivetrain to be able to predict longevity based on quantity for sale versus original sales figures. If a model sold 100k per year for 10 years and only 3 were for sale in year 13, that isn't a great sign. Cheap cars will tend to have cheap owners who are more likely to skimp on maintenance, typically leading to more accrued issues and a shorter lifespan for the vehicle. Some cars are just poorly engineered, and the markets are relatively efficient in pricing resale value. The definition of "high mileage" is going to vary by who you ask. Domestics 150k, German 80k, Japanese 200k, Korean 100k. These are subjective averages (some cars like Theta engines, Darts, even late model GM 6.2s have engine failures <40k), based on when they start disappearing due to repairs being more than the vehicle is worth, but based on what I saw then and kind of observe still.

Leaning on those prior mentioned product mixes, keep in mind that Japanese manufacturers weren't in the American market 60 years ago, so market mix would be wildly different. (Multiple 400k+ mi Toyotas in my family, along with 60 year old GMs, but with aftermarket or rebuilt engines.) The cost of vehicles (and repairs) relative to prevailing wages will impact the repair vs replace balance. Trade publications like Cox/NADA/Adesa/etc. are always cited by financial blogs when mentioning consumer spending/state of economy by average age of cars on the road. Why cars get junked or totaled has shifted drastically, too. Steel bumpers were easy to replace, modern bumper covers with styrofoam backing and aluminum crumple zones, not so much. Tolerances is a vague term in that veiled PR piece on that wiki article. Machining has improved. Tech like direct injection and improved lubrication (synthetics) have done much more in terms of efficiency and longevity. In a lot of cases, manufacturers try to get more and more horsepower from the same displacement by pushing tighter engine tolerances (crank/main bearings, pistons/rings, valvetrain) and things like higher compression ratios and revs, leading to more heat and earlier failure. So while you have better initial engineering, you are closer to the point of failure. For another example, interference engines will grenade themselves if you ignore timing belt maintenance, but in the meantime, you get more horsepower by getting more air into the cylinders.

A v6 Camry or Accord is going to be have more hp, be faster,more reliable at same age, be quieter and get 3x the mpg than nearly any muscle car of the past. Unfortunately it seems that many Americans prefer giant vehicles that place more emphasis on their size (and status) than materially important factors like reliability engineering or fuel economy.

Obviously these are ancedotal examples, they can be confirmed by wasting hours reading about cars and watching mechanic review videos from people who work on them daily (I am partial to the CarCareNut on YT).