The Beat Goes On: Car Durability

When an automotive engineering team is given a project, some of the first questions involve the design's longevity parameters.

What is the product life expectancy?

How long do competing cars last?

How long is the warranty and what is the claim profile over time?

Every component has a quantifiable Mean Time Between Failure (MTBF).

Cars are built to last just long enough to stay competitive.

Planned obsolescence and product lifespan strategies are part of every business.

So designers source the least expensive components consistent with product life expectancy targets.

Durable Radial Tires Create Disaster

The last thing any builder wants to do is accidentally build cars that last. Nothing is worse than creative destruction, the advance of technology making old ways obsolete.

A good example of this occurred in the tire business. Tires used to last around 25K miles. These were bias-ply tires with fiberglass belts.

Michelin introduced steel-belted radial tires in Europe, starting in 1948. American automobile companies and their cronies in the tire industry resisted the modern tire. Expensive retooling of both car and tire plant was anticipated.

Other nations adopted the technology until the US was surrounded. It took about 30 years to get across the pond and wreak havoc. The new tire technology produced tires that lasted 40-60K miles.

Radials were more fuel efficient and were installed on cars built overseas. When the 1978 fuel crisis struck, foreign radial tires, led by Michelin, made big market share gains.

Disaster struck the US tire industry. Because the new tires lasted longer, there was about 50% surplus manufacturing capacity.

Firestone tire, previously an industry leader, began a decline and never recovered. Trashy products disintegrated, 25,000 workers were laid off, and tire company stock prices collapsed.

By 1983 nearly every new US car shipped with radials.

The manner in which American industry failed to adapt to change was not lost on the Japanese. American cars of the late 1970's were some of the shabbiest products ever mass produced prior to the rise of China.

American car manufacturers, with what they believed would remain a captive market, deliberately built cars that didn't last to force consumers to buy the latest model.

Japanese car manufacturers built a beachhead in America with carefully engineered cars that lasted nearly twice as long.

During the same time frame, synthetic lubricants, fuel injection, better internal tolerances, and computer control modules reduced engine wear.

The result is a crisis which has engulfed the entire industry. As in the radial tire fiasco, extended longevity meant that fewer new cars were needed.

The reliability race has spiraled out of control. The old phrase "worked themselves out of a job" comes to mind.

Today the global industry has the capacity to build 30% more cars than the population has the ability to buy.

Demolition Derby

The reality is that cars have a life cycle which depends on initial quality, mechanical configuration, and maintenance. A car lasts until someone decides the cost of maintenance exceeds the benefits of ownership.

This means that very cheap or rapidly depreciating vehicles will have lower life expectancies.

But some cars go on to become classics, collector cars, or just keep providing basic transportation for decades.

Somewhere down the road, assuming proper maintenance, a major component is going to fail. People who successfully maintain cars with high miles are good at delaying the decision point of major engine and transmission rebuilding. When it comes, the still-clean car is often worth the investment.

Modern cars are becoming more complex and difficult to maintain.

Many cars decay to the point of not being worth fixing long before the drive-line dies. Electronics tends to develop faults, upholstery rips and fades, power "everything" breaks down and costs too much for third owners to justify. These small defects are allowed to accumulate on poorly maintained cars.

This is why rolling chassis records, cars that went millions of miles, tend to be held by simple cars like Volkswagen Beetles and old Volvos and Saabs.

The 200K Barrier

In modern cars, the metal used in the body and frame is corrosion-resistant, electro-galvanized steel.

Due to this improved corrosion protection, car bodies are lasting longer than their first drive-train. Running 200K or even 300K is within reach.

In a Consumer Reports' 2007 questionnaire 6,800 respondents reported more than 200,000 miles on a car.

Design issues restrict some vehicles from breaking the 200K barrier. High piston travel per mile due to the lack of an overdrive gear is a killer. Turbochargers are inherently self destructing, and attract the most aggressive first owners.

The key to vehicle longevity is continuing maintenance.

Most people think following the user's manual service interval is enough.

Not.

Maintaining a car starts with the way it is driven.

I knew a guy some years ago who drove a 1963 VW Beetle with 235K on it. Every other employee had a flashy ride, but not "the Fat Chinaman." No amount of ridicule could goad him into a new car, though he had plenty of money.

He would carefully start the Bug and let it idle for 10 minutes before going out in traffic.

Cold starts, short trips, and hard driving on a cold engine are the equivalent of smoking and drinking for cars.

Experienced heavy diesel mechanics have a rule: the life expectancy of an engine is proportional to the rate that fuel goes through it. Engines that are carrying heavy loads, whether a loaded commercial trailer, or just a heavy foot up the freeway ramp, have faster wear.

Harsh or awkward clutching and shifting, as well as lugging of manual transmissions is another drive-line killer.

Using throttle lift to gently up-shift an automatic, rather than keeping the gas down so there is a jerky shift, will add years to its life. Trailer towing and mountain driving in summer can overheat a drive-line even when the engine does not overheat.

Front end ball joints, chronic alignment, and power steering problems are the death knell for many cars.

Hitting curbs, parking stops, speed bumps, pot-holes and road hazards will damage front end parts, accumulating a sloppy front end before the drive-train fails.

Lengthened oil drain intervals are popular today. I do not follow them. Five or six thousand miles on premium synthetic oils is my maximum.

At minimum, adhere to the "severe service" maintenance schedule in your car's owner's manual, using full-synthetic lubricants.

When it's time to deny warranty claims, automakers will often insist that you live in a severe service area.

Like maybe the southern half of the US where it gets hot. Or else the northern half where you should have realized it gets cold.

Longest Lasting Cars

As stated above Japanese cars are the most likely to provide prolonged mileage. Searching for used cars on craigslist, eBay, and autotrader, you will routinely find Hondas, both Civics and Accords, with 220K or higher miles. Many are still running perfectly and selling for several thousand dollars.

But note: Honda has settled a class action for odometer misstatement. Many of the company's products may have less mileage than the odometer shows.

Toyota is also pretty durable, but I consider Honda to have a significant edge.

US automakers have moved closer to the Asians, and Europe is far behind.

Volvo was once a high mileage marque, but was destroyed by Ford ownership.

Consumer Reports lists the following cars as "good bets" for longevity;

I expect future cars to continue the trend of increased vehicle longevity. The coming clean diesel cars are likely to last a very long time.