Will Auto Stop-Start Technology Wear Out Your Engine? (2023)

Will Auto Stop-Start Technology Wear Out Your Engine? (1)

Even if the extent of your automotive technical knowledge begins and ends with television commercials, you probably understand that most engine wear takes place when you start your car. Now that we’ve arrived at a point when most new cars have auto-stop/start technology, which increases the number of starts in an average commute by 100x, are we more vulnerable to engine and component failure?

What Is Auto Stop-Start Technology and Why Do We Need It?

Since the Obama Administration finalized standards in 2012 to encourage the automotive industry to reach a 54.5 miles per gallon corporate fuel economy average by 2025, manufacturers have been employing every means possible to squeeze another mile out of a gallon of gasoline. A combination of aerodynamics, weight savings, electrification, hybrid technologies, and advanced engine management software has gone a long way, but it doesn’t take a rocket scientist to understand that you save a lot of fuel when the car isn’t running at all.

Auto stop-start technology automatically shuts the engine off when the vehicle comes to a full stop, and then starts it again when the driver wants to get moving. If your commute consists of a single stoplight and a long stretch of highway, auto stop-start isn’t going to save a lot of fuel. However, if you’re like most of us, with a ton of stop-and-go traffic on your way to and from the office, it can make a significant difference in your fuel economy, typically between three and five percent.

How Does It Work?

There are a few different suppliers of such technology, but one of the biggest is Denso. It supplies the technology to all three American manufacturers, as well as vehicles in Land Rover,Audi, Fiat, Hyundai, Toyota, and Volvo‘s product lines.

In general, auto stop-start senses that the vehicle has come to a stop, the engine RPM has fallen either to a full stop or close to it, and that the brake is depressed.

At that point, the system shuts the engine down and disengages the transmission. When the system senses that the driver is taking their foot off the brake, it restarts the engine while the transmission is still in gear.

(Video) Why Not to Buy a Car with Stop/Start Technology

This technology is more than just a starter that spins the engine to a start more frequently, as you’ll soon find out, but the starter is the single most important component.

How is the Starter Different?

Since itsvery introduction, the electric starter on your car has had two jobs: Primarily,to spin the flywheel to start the engine. But they also need to get the pinion gear — the little spinning gear you can see in the animation below — out of the way so that it’s not engaged with the ring gear on the flywheel once the engine is running.

Will Auto Stop-Start Technology Wear Out Your Engine? (3)

For a vehicle that only needs to start a few times a day, it’s an ingenious little device that has existed almost unmodified sinceCharles Kettering received a patent for it in 1917.


But vehicles with auto stop-start systems have to fire up dozens (perhaps hundreds) of times in a single commute. A traditional starter like Boss Kettering’s simply won’t do the job.

(Video) The truth about engine stop start systems | Auto Expert John Cadogan

Denso has three different types of auto stop-start starters, depending on the application themanufacturer needs:

  • The first is a pretty traditional starter, but it’sengineered to be more durable, with dual layer, long-life electrical brushes and a unique pinion spring mechanism that reduces ring gear and flywheel wear caused by a typical starter by about 90 percent.
  • The second is a “Tandem Solenoid” starter that allows the engine to re-engage with the starter motor anywhere between idle (about 600 RPM) and zero RPM. That means shaving a second and a half off a restart when compared with a traditional starter.
  • The most advanced Denso starter was developed in partnership with Toyota. It’s called a “Permanently Engaged” starter, and as its name suggests, the pinion gear is permanently meshed with the ring gear on the flywheel, which completely eliminates any lag time when the vehicle needs to be restarted.

When you’re out shopping for a new car, sample a few different vehicles to see how they accomplish the auto stop-start system. There are some that do it more or less seamlessly, while others may do so with a bit of a shudder.

Starter manufacturers alsouserubber shock absorbers and clutches to isolate engine oscillations that help reduce engine-restart noise and engine-stop vibrations.

But the big difference between a smooth start and a rougher oneis down to whether they’re using a Permanently Engaged starter or not.

What About the Transmission?

The transmission represents a huge challenge in restarting an engine. In fact, the only vehicles that had auto stop-start technology prior to 2007 were those with a manual transmission.

When you start your car in the morning, whether you drive a car with a manual or an automatic transmission, the car is either in Park, Neutral, or in gear, but with your foot to the floor on the clutch.

But when you’re in traffic, you’re not shifting the car to park every time you come to a stop. So how does the transmission not stay engaged using an auto stop-start system? They automatically shift into neutral when the vehicle is stopped. Some incorporate an “Auto Hold” feature that allows the driver to release brake pressure while the engine is still turned off. It reengages when the driver hits the accelerator.

(Video) STOP Destroying Your Car Engine! (With These Tips)

How About Engine Wear?

Cold engine startup is commonly recognized as the most vulnerable time for internal engine components. The lubricant is cold, and it hasn’t had time to pressurize and lubricate all of the moving components on the top of the engine.

Auto stop-start systems aren’t as potentially damaging as cold starts, though, simply because the engine isn’t cold. Not only are the engines at operating temperature before the stop-start system begins to work, the vehicles also use electric water pumps to maintain optimal engine temperature when they’re stopped. If the engine is off long enough to reduce engine temperature significantly, the engine will automatically restart.

Secondly, while the engine’s oiling system isn’t completely pressurized as it is when it’s running, the oil in the passages hasn’t been allowed to completely run down into the oil pan.

Finally, suppliers are addressing wearwith dry lubricants on components like main engine bearings. Engine bearings are typically designed to withstand 100,000 start cycles. New bearings are now in use that are designed to withstand 250,000 to 300,000 start cycles. Federal Mogul, for example, has been incorporating polymers on the connecting rod bearings for cars with auto-stop/start systems to reduce friction when oil isn’t pumping.

What if I Hate It?

To date, every vehicle with this technology allows you to manually override it at the push of a button:

Will Auto Stop-Start Technology Wear Out Your Engine? (6)
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The downside is that (A) your fuel economy will be reduced by three to five percent, and (B) you’ll have to turn it off every single time you get in the car. No manufacturer that we know of allows you to permanently disable the function.

Owners of sporty cars with “Dynamic” or “Sport” modes will note that selecting those modes will automatically disable the system, too.

None of this technology is completely settled, and manufacturers and suppliers are working to develop new methods of accomplishing the same goals without the technical hurdles.

For example, Mazda has a technology called i-Stop that doesn’t use a starter for restarts at all. It uses engine combustion. As a driver releases the brake pedal, the fuel injector in one cylinder fires and the spark plug ignites, allowing the engine to start with combustion, rather than an electric starter motor.

In the short term, though, you don’t have to worry too much about whether your engine or its various components are being damaged by frequent starts. They’ve been engineered for it, and they’re different than the components in a vehicle without this technology.

Audi, auto start, Fiat, Fuel Economy, Hybrid, Hyundai, Land Rover, Mazda, Research, Technology, Toyota, Volvo

(Video) Auto Start/Stop is *DESTROYING YOUR ENGINE!!* Here's Why!!


What is the downside to the start/stop engine feature? ›

Disadvantages of Automatic Engine Start/Stop Systems

Another drawback of these systems is that they do require idling the main engine, creating additional hours of wear on the main engine and loading of the DPF exhaust system.

Does a stop/start function drain the battery? ›

A. The start/stop feature of your car is designed to save fuel and lower vehicle emissions. AAA's engineering department did some tests and found that fuel savings have been as high as five percent. Regarding extra wear and tear, so far tests have shown no significant change in battery or starter motor life.

How much fuel does start/stop actually save? ›

Depending on the style of driving, Start-Stop technology can achieve fuel savings of up to 15%. However, the effectiveness of the system depends on many factors, including the area of use. During urban use, the automatic Start-Stop system causes the engine to switch off at standstill.

Is Auto start-stop necessary? ›

Idling can cause issues with spark plugs, and if the engine isn't warm enough to fully combust fuel it can leave residue behind. Auto start-stop is much better for engines than constant idling. And if most of your driving is on the highway, auto start-stop will have no effect on your vehicle.

What are the pros and cons of auto start-stop? ›

Your Car's Start/Stop Feature: The Pros and Cons
  • Start/stop technology, otherwise known as auto stop-start, idle-stop, etc., is a relatively new feature designed to help car owners save on fuel use. ...
  • More mileage.
  • Better for the environment.
  • Wear and tear.
  • It can get really annoying.
12 Feb 2019

How long does a stop/start battery last? ›

How long does a Stop Start battery last? Conventional lead acid batteries can last for up to 4-5 years if maintained properly.

Can I change a stop/start battery myself? ›

It's best to have a dealer or workshop install a stop-start battery. They will have the diagnostic equipment needed to reset the car's active energy management system. Reprogramming tools can be purchased, but doing it yourself is only recommended for experienced hobby mechanics.

Do stop/start engines need special batteries? ›

Start-stop systems require a battery with modern technology, because normal starter batteries are not designed to meet the higher demands of these vehicles. The architecture of the electrical system in modern vehicles requires a compatible battery technology in order to function properly and reliably.

Does stop-start use the alternator? ›

Used in many modern vehicles, StARS (Stop start Alternator Reversible System) consists of a reversible alternator that replaces the conventional alternator and starter motor.

Do stop/start systems really save fuel? ›

Does stop-start help save fuel? Yes - in situations where you're stationary with the engine idling, such as in heavy traffic or waiting for traffic lights to change, it will save however much fuel would have been used by the engine while the car is stationary.

Does Auto Stop-Start use more fuel? ›

Myth #1: Stop-start engines use more fuel

This saving may seem small but would certainly add up over the lifecycle of your car. In any case, the data shows that they certainly don't use more fuel.

Is it better to idle or stop and start? ›

Turn off your ignition if you're waiting more than 10 seconds. Contrary to popular belief, restarting your car does not burn more fuel than leaving it idling. In fact, idling for just 10 seconds wastes more gas than restarting the engine. Warm up your engine by driving it, not by idling.

Can you turn stop-start off permanently? ›

As stated before, no automotive brand enables consumers to permanently turn off Autostop. However, it can be temporarily disabled by clicking the “disable” or “off” button. Besides this option, Start-Stop has been forced on consumers by automotive companies, who offer no way to permanently disable this function.

Is engine start/stop button good? ›

The Start Stop Engine feature does not only function for convenience and comfort, but also as added security. This button certainly makes it easier for vehicle owners to turn on or off the vehicle engine. Not only that, this system also provides additional protection because it can reduce the risk of a car break-in.

What is the benefit of the auto start/stop technology? ›

Stop/Start Technology automatically stops and starts the vehicle's engine under certain conditions. By turning off the engine when not needed, Stop/Start Technology can help improve fuel efficiency, thereby reducing greenhouse gas emissions (compared to the same vehicle with Stop/Start Technology not in use).

Why do newer cars turn off when stopped? ›

A vehicle start-stop system or stop-start system automatically shuts down and restarts the internal combustion engine to reduce the amount of time the engine spends idling, thereby reducing fuel consumption and emissions.

Why do new cars stop and start? ›

The idea behind the start-stop system is simple: If the engine is stopped for short periods, for example while waiting at traffic lights, fuel consumption and emissions are reduced. In this way, the automatic start-stop system helps to save fuel and protect the climate.

How long does a battery last on a stop and start car? ›

This type of battery lasts on average 3 to 5 years. AGM batteries are ideal for powerful vehicles with stop/start systems. They typically have a longer lifespan than EFB batteries. The EFB battery is for simpler stop/start electric systems with smaller engines.

Do you need a special battery charger for stop/start cars? ›

If your car has start/stop technology, you'll have an AGM or EFB battery. A conventional charger isn't suitable for these types of batteries and you'll need a 'smart' charger instead.

How many times can you start and stop a car before the battery dies? ›

A battery is actually about 60Amp-hours, so you can do this about 3600 times. If you actually start your car once a day, the starter motor lasts typically 10 years, or 3600 times, so there's an even chance you'd wear out your starter if you tried.

Do stop/start batteries need special chargers? ›

If your vehicle has Stop/Start Technology, it will be fitted with either an EFB (Enhanced Flooded Battery) or an AGM battery (Absorbent Glass Mat), so you'll need a smart charger to charge these types of battery safely. Before you start charging, ensure the battery terminals are clean and free from corrosion.

Can you jumpstart a car with stop/start technology? ›

Yes you can jump start a car with a stop start battery. These are more common in modern cars and it's best to check your car's handbook first. However, most stop start cars can be jump started in the same way as a traditional key ignition.

Do stop/start cars need special oil? ›

Since start-stop engines spend so much more time under boundary lubrication, it's vital to use an oil with superior film strength and additive quality. AMSOIL Signature Series Synthetic Motor Oil delivers. It provides 75% more engine protection against horsepower loss and wear to help protect today's advanced engines.

Do you need special oil for stop-start? ›

Why do you need engine oil specially designed to protect against stop-start wear? All that constant stopping and starting in traffic causes increased microscopic engine wear. Because of increasingly busy traffic, drivers today are experiencing more and more stop-start driving.

Does Autostop eliminator void warranty? ›

The Autostop Eliminator also does not void any car warranties. In less than five minutes, this disabler of the auto start/stop system can be functioning on your vehicle.

What new cars do not have start/stop technology? ›

The Suburban, Tahoe, Escalade, ford edge SUVs, and Yukon models do not have start-stop technology. Still, many SUVs have this technology in their automobiles. Automotive companies are now offering the choice to disable this technology if they want in many cars.

Does Auto start-stop wear out starter Reddit? ›

No. Auto stop/start is a well proven system with decades of engineering behind it. The starters and fuel pumps are specifically designed for it in cars with the feature - to deal with the extra cycles put on them. In cars with the system, they restart with near zero extra fuel use.

Does turning your car off at red lights save gas? ›

Unless you drive a vintage, carburetor-equipped vehicle, you'll save fuel and reduce carbon dioxide emissions by turning it off. Some drivers think that idling uses less fuel than restarting, but our research has found that drivers save fuel and reduce emissions by shutting down for stops as brief as 10 seconds.

Does auto start use a lot of gas? ›

Starting a car does not use much gas anymore, but it does add wear and tear to your starter, relays, and battery.

Do you waste gas if your car is on and parked? ›

Wastes gas. Leaving your engine running consumes gasoline. As a matter of fact, allowing your car to idle for two minutes is equivalent of driving a mile. You can waste almost a gallon of gas if you leave your car idling for more than an hour.

Do you waste gas if your car is off and parked? ›

A. Just 10 seconds of idling uses as much gas as restarting your car, according to the California Energy Commission Consumer Energy Center, which recommends you shut off your car when you're parked (at a drive-through business, for instance) for more than 10 seconds.

Does sitting in the car with the AC on waste gas? ›

Yes: The alternator, which is powered by the engine, is what provides energy to the air conditioner. The engine runs on fuel, meaning you are using up gas when you run the AC.

What happens if you press start/stop button while driving? ›

What actually happens, at least in the case of this Ford Fusion, is rather undramatic: the car carries on regardless. It is still possible to turn the car off on the move however (something you might need to do in the case of a mechanical issue like a stuck throttle), by simply holding the button down.

Why doesnt start/stop work all the time? ›

Stop-start won't operate when reverse gear is selected or a parking aid is active. Having the wheel turned at an acute angle will prevent it working too. The system realises there's a high chance you're manoeuvring and will find the engine cutting out every few seconds more than a little irritating.

Is it harder to steal a push to start car? ›

Yes, in many circumstances keyless cars are easier to steal. That said, it also depends on the particular model, as well as the situation. Some models have keyless entry that unlocks the doors when the key is close-by but still have a conventional key that is physically put in the ignition to start the car.

Is push start better than key? ›

Advantages. The pros of a keyless system include security and convenience. It's much harder to steal the vehicle since a potential thief would need your key fob. It's also more convenient since you only need to keep the key fob in your pocket.

Does Auto start-stop drain your battery? ›

Even the functions that save gas, drain the battery. “For example, a lot of people have start-stop, so when you go to a stop sign your car immediately shuts down. It saves gas but then it has to restart again and that is where your car battery is being utilized most,” said Quincy.

How much gas does Auto stop-start save? ›

Most people think the amount of fuel saved using a start-stop system is negligible, but in reality, that fuel burned while idling at a stop adds up quickly. A study by the Society of Automotive Engineers found that using start-stop can see a car's fuel economy improve by over eight percent in heavy traffic.

What is the point of autostart? ›

Auto Start/Stop Technology automatically shuts off the engine when the vehicle comes to a full stop and idles for more than a few seconds. Once the driver puts pressure on the accelerator, then the engine turns back on. It's simple, and some say it can save between 3-5% of gas in stop-and-go traffic.

Can the start/stop feature be turned off permanently? ›

Auto Start-Stop can be temporarily disabled. To turn the system off, press the Auto Start-Stop Off button on your instrument cluster. Note: this is not a permanent change, you will have to deactivate it each time you start your vehicle.

Does start/stop waste more fuel? ›

Myth #1: Stop-start engines use more fuel

This saving may seem small but would certainly add up over the lifecycle of your car. In any case, the data shows that they certainly don't use more fuel.

Can you turn off Stop/Start engine? ›

If the vehicle is equipped with the Stop/Start deactivation switch, you can push the switch to turn off Stop/Start. Stop/Start is turned off when the LED indicator on the switch is not illuminated. To help maximize the fuel economy benefit, Stop/Start is enabled each time the vehicle is started.

Is auto stop a good feature? ›

Stop/Start Technology automatically stops and starts the vehicle's engine under certain conditions. By turning off the engine when not needed, Stop/Start Technology can help improve fuel efficiency, thereby reducing greenhouse gas emissions (compared to the same vehicle with Stop/Start Technology not in use).

Is it better to idle or start and stop engine? ›

Unless you drive a vintage, carburetor-equipped vehicle, you'll save fuel and reduce carbon dioxide emissions by turning it off. Some drivers think that idling uses less fuel than restarting, but our research has found that drivers save fuel and reduce emissions by shutting down for stops as brief as 10 seconds.

Why do newer cars shut off when stopped? ›

A vehicle start-stop system or stop-start system automatically shuts down and restarts the internal combustion engine to reduce the amount of time the engine spends idling, thereby reducing fuel consumption and emissions.


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