It is too early to tell, as most electric cars on the road today have only been driven for a few months.
The few vehicles that are less than a year old are the first to go off the production line. Teething troubles and other problems are normal and do not affect the long-term quality of vehicles produced later.
So, DIRECT evidence is sketchy and will remain so for a few years.
Indirect evidence shows that the most expensive parts in an electric car are INCREDIBLY reliable.
- The reliability of industrial-sized electric motors, such as those used in electric cars, is very high. Tesla’s tested them to 1,000,000 miles without any problems. This is at least 8x more than the typical gasoline engine.
- Because the battery packs contain many thousands of batteries, it is very unlikely that one battery will fail. The fact is that each battery will eventually fail over the lifetime of your car. This will gradually reduce the range available. Initial predictions were that batteries would lose range at 10% per 100,000 miles. This isn’t terrible. Three factors appear to be driving that number closer to 3% for every 100,000 miles.
- To reduce cell failure rates, manufacturers are improving their ability to set charge cycles and monitor battery temperatures.
- Drivers are more informed about the “best practices” to keep their batteries healthy. The “80/20 rule”, which states that you should not charge your car more than 80% or drain it less frequently than 20%, is a good example. It’s possible to do this for long trips and other reasons, but not every day.
- It is now clear that the INITIAL rate for battery degradation (10% per 100,000m) decreases over time. So, battery reliability actually increases with age.
This means that the only thing that is likely to fail in your car is not the motor or battery pack, which are the costly bits.
Many other parts that are commonly defective in gasoline/diesel cars don’t even exist. Things that are required to be serviced frequently, such as oil changes, antifreeze, fuel injector cleaning and transmission fluid changing, or air filter, don’t exist in electric cars.
Even the things that both types of cars have in common, such as the brakes, are more reliable in an electrical car. This is because the electric car has regenerative brakes (which uses the motors and batteries to slow the car down) which means that hydraulic disk brakes are used much less frequently. The brake pads are said to outlast the rest. I can attest to that, given how often I use them.
The total number of moving parts in the entire Tesla Model 3 drive train is 17.
The total of a traditional car is around 200 parts.
According to some sources, the entire car has only 210 moving parts, compared with about 2,000 for a standard car.
This is an important point. Less parts mean less chance of things going wrong.
Consider something simple, like your car’s radio. Other cars have two knobs for volume and tuning, and perhaps a dozen buttons. These controls can send data to the computer, which controls the radio in any modern car. The Tesla uses a touch screen to control everything. This controls the radio. There are no buttons or knobs that can be broken. There are no moving parts, so dirt and grime cannot get in.
CONCLUSION:
It is not known how reliable these cars are when they reach 20 to 30 years of age.
However, basic engineering principles suggest that they are extremely reliable.
People with a lot more knowledge than me on this subject say that a Tesla will live between 300,000 and 600,000 miles.
While some cars are built to last longer than others, the average American car’s life expectancy is just under 200,000 miles.