Does Auto-Start/Stop Wear Out Engine Components?

Start Stop

Nowadays people will say just about anything to prove their point. Not only will they continue to confuse themselves, but they will also confuse your thoughts on a subject.

They will argue about the quality of the fuel you should put in your car, the pressure you should have in your car’s tires, and even weigh up the pros and cons of Auto-Stop/Start technology. Even if you cannot judge what is right and what is wrong, you can certainly find out the truth from the Internet.

This is where this article comes into the spotlight. So does Auto-Start/Stop technology damage your engine and its components? That is what we want to find out!

What Is Auto-Stop/Start Technology?

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Before we talk about Start/Stop technology in detail, let’s take a look at its history and its significance.

The Auto Start/Stop system first came into the automotive world in the 1980s when Volkswagen used it in its top-of-the-range vehicles such as the Passat and the Golf. The technology did not get off the ground at first, but today we can see it in almost every other car regardless of its size.

Why is this technology so popular today compared to the past? Because the world is more focused on saving the environment. When fuel burns, harmful chemicals and gases like carbon dioxide and carbon monoxide are emitted. These gases suffocate the environment day after day.

Scientists and engineers have tried to reduce gas consumption by using advanced methods to improve aerodynamics, engine, and vehicle design. Later, they discovered a very trivial fact: when an engine is not running, it does not produce life-threatening gases. The Auto Start/Stop technology is the implementation and practical application of this fact.

With the Auto Start/Stop technology, the engine is switched off completely when a vehicle comes to a standstill. The engine ignites again automatically as soon as you decide to start moving again. This innovation is only useful if you make several stops along the way. You will not save fuel when driving on the motorway.

However, most of the journeys everyone makes are on city roads, so there is something to be gained from using this technology. Even if the Start/Stop action saves a small percentage of fuel, in the long run, it can make a significant difference in your fuel costs.

How Does the Start-Stop Technology Work?

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There are a number of companies that produce such technologies, but the most popular of them is Denso. You might recognize Denso if you have ever worked with your car’s air conditioning. The Japanese company supplies the Auto Start/Stop technology to all major American car brands like Ford and also to other global car manufacturers.

The Auto Start/Stop system senses that you have applied the brakes and the engine speed comes to a stop. As soon as it senses that you have come to a standstill, the system shuts off the engine. It starts the engine again as soon as you take your foot off the brake.

Difference between Regular Starter and Auto Start

Every car has an ignition or a starter to start the engine. The starter does this by a very simple process of spinning the flywheel and igniting the engine. However, this simple mechanical system is not suitable for normal starts.

With the Auto-Start/Stop technique, the engine is started several times during a ride. Therefore a completely different component is used. This other component can handle hundreds of starts in one day without feeling the heat.

Damage to the Vehicle

The engine of a vehicle is vulnerable when it starts. The engine has to heat up the lubricants inside it so that they can flow easily to any angle. A cold engine is more susceptible to damage, and that’s what many argue about when they talk about Stop/Start technology. Yes, the engine can be damaged when it’s cold, but Auto-Start/Stop technology is only activated when the car is on the road. This only happens when the engine has warmed up to operating temperature.

Even if you sit at a stop light for about a minute, this time is not enough to cool the engine lubricants. Therefore, the Auto Start/Stop technology does not cause much damage. In case you need to stand still for a longer period of time, the system is designed to start the engine automatically when it notices that the lubricants are getting cold.

In addition, the technology does not allow all the oil to flow back into the sump, so when the car is restarted, a considerable amount of fluid is already left in the engine compartment. Even then, to further reduce engine wear, engineers now use dry lubricants in key areas such as the engine mounts. Modern engine mounts are designed to withstand many restarts even when there is no oil to reduce friction.

Is There A Way Round It?

Frankly speaking, saving the environment is the responsibility of every human being. It is better that we, as responsible people, use the systems set up by experts to reduce the harmful effects on the environment. But not everyone thinks so. Some people prefer less technology over the dominance of technology, and they do not like such innovations. Car manufacturers respect this, and as such they always offer manual override of the system.

If you don’t like the technology, you can switch off its functions simply by pressing a button. With this button, you can switch between using and not using the Auto-Start/Stop function. You may not want to keep your foot on the brakes while standing at a brake light. The engineers have even solved this by providing you with a separate button that allows you to keep the technology in play while you take your foot off the brakes.


So does the Auto-Start/Stop technology damage your engine? Yes, it does, but not to the extent that you need to worry about it. The system is designed to minimize engine wear while preserving your contents.

Written by: Magnus Sellén

Founder, owner & main author of Mechanic Base. I have been repairing cars for more than 10 years, specialized in advanced diagnostics & troubleshooting. I have also been a drifting driver and mechanic for over 7 years.