What You Need to Know about Stop/Start Systems

How Stop/Start Systems Work On The Road

A Car Pro Show radio show caller wanted to know if he could purchase a car these days without start/stop technology. He was concerned about the long-term effect on a carís engine, and, frankly, just didnít like it. As I explained, the technology is still so new, it is hard to say whether start/stop systems will cause problems or not, but I have had the same concerns.

How Stop/Start Systems Work

Although start/stop systems are fairly new to cars in the United States, it was Volkswagen who debuted it in Europe in 1983. About 10 years ago, Mazda announced a similar system that did not engage and disengage the starter, but it never really came to fruition and proved to be unreliable.

If you are not familiar with this system, simply put, when you come to a stop, like a red light, the engine shuts down, but essential other components continue to run, like the air conditioning system, power steering, brakes, sound system, etc. When you take your foot off the brake to press the gas pedal the engine restarts and you go on your merry way. In a vehicle with a manual transmission, the system operates from the clutch pedal instead of the brake.

Automakers and the engineering community say start/stop technology improves fuel economy by 5 to 10 percent, although I am not confident in their findings. There would have to be some amount of gas savings while your vehicle is not idling, and there would be fewer emissions coming out of your tailpipe.

To put your mind at ease about the mechanics of the start/stop system, vehicles that have the system have heavy-duty starters, and they have larger batteries, which are essential since all the accessories are running strictly on the battery when the engine stops.

Real-World Driving

So what are the real-world driving characteristics of this technology? I can tell you that for me, it drives me crazy, especially in heavy traffic. I drive over 100 new cars per year, and for the past year or so, most of the vehicles I drive and review do have the start/stop system. Some automakers, like Ford, have committed to putting it in every vehicle they produce.

One observation I have noticed is that the smaller the engine, the more seamless the feel of the engine turning on and off. With larger engines, you tend to feel the system more. Iíve been in cars that the engine noise going on and off is quite loud, and you actually strongly feel a vibration every time the engine cranks again. I always note in my car reviews when the system really bugs me.

Another downside I have experienced in some vehicles is when the outside temperature is high, the air conditioning system does not work nearly as well with the engine stops. A long traffic light can make the interior temperature uncomfortable. With some vehicles, when the outside temperature is hot, there is no difference in the air conditionerís output, so if you are in a hot weather area, this is something you would want to pay attention to when test-driving.

Disengaging Stop-Start

Here is the good news: almost every vehicle I drive that has start/stop also has a switch to turn the system off, but two GM SUVs recently (the 2018 Buick Enclave and 2018 GMC Terrain) did not have a way to disable it. If you are like me and donít like this technology, in most cases, you can turn it off. The bad news is that in almost all cases, you have to disengage the system every time you start your vehicle.

In my personal case, my Range Rover has the start/stop system and over time, I have gotten used to hitting the start button to crank the engine, then I immediately hit the button to turn off the start/stop system. If by chance I forget, I catch at the very first instance of stopping.

Right now, with low gas prices, this technology will save most people, on average, less than $50 per year, so you have to make up your mind on whether you choose to use start/stop or not. If it turns out that this technology causes starter failures at a greater rate, there will be no savings.

Final Thoughts

As I told the caller on the air, I wouldnít let start/stop be a deal breaker if the car you want has it, but be aware of it when car shopping and test-driving your next new vehicle. If the car you are considering has the system, and you donít like it, make sure it can easily be turned off.

Related Reading:
2019 Buick Envision Updates Include Start/Stop Disable Button
Related Articles
Americans Confused About Self-Driving Technologies, Study Finds
Many drivers donít fully understand partially automated driving systems according to a new AAA study. Researchers say that 40 percent of drivers surveyed misjudged a systemís capabilities based on th... More ›
A Car Shopperís Guide to Navigating Auto Shows
Americaís love of automobiles shows up no brighter than at auto shows. They beckon car buyers and enthusiasts with their spotless, shiny new vehicles, glamorous exotics and super cars along with conce... More ›
Three years ago my wife and I rented a Skoda with start/stop technology at the Copenhagen airport and drove to Prague and back. To be sure, the Skoda is a weakling, but the start/stop technology simply degrades vehicle performance. Driving around Berlin for a couple of days, we learned that accelerating from stop lights problematic; the car couldn't be counted on to get up and go. It simply dragged it's derriere across intersections. To think that a Toyota Supra has this sort of technology is difficult to imagine. Do the new Mustangs or the mid-engine Corvettes have start/stop technology.?
The Car Pro
Most cars do but as long as it has a disable button, I'm OK with it, you get used to turning it off.

Thanks for your thoughts!

Jerry Reynolds
The Chevrolet Traverse and Equinox you can add to the list of cars that does not have the ability to shut off the stop/start technology.
You can also add Subaru Forester '19. The simple fact that this feature cannot be permanently turned off is one of the dumbest things ever designed for two reasons, safety and mechanical failure. If I am stopped and the car turns off, and if something is headed my way and I need to move out of the way, I guarantee you, those lost seconds will mean the world. And continually engaging the starter will decrease that life a ton.
Is there a list out that has the cars with the start/go feature and the ones that have the ability to shut it off.
The Car Pro
I don't know of such a list. I'd assume most have it, and most (except for some GM vehicles) will allow you to disable.

Jerry Reynolds
Sandi R
In your opinion which small SUV is the best that doesn't have the start/ stop feature?
The Car Pro
Sandi, I don't really know of any small SUVs that don't have, but most have a disable button you get used to hitting every time you start the car. Some of the GM SUVs do not have the button.

Typically Toyota RAV4 and Honda CR-V are the most reliable in small SUVs.

Jerry Reynolds,
My 2018 Mazda CX-5 does not have it, but it has cylinder deactivation to save gas, which in my opinion is even worse.
Darrin Francis
My elderly father just purchased a 2019 Chevy Equinox with the auto Shut-off (start/stop) feature. The safety issue he encountered was that after pulling into a parking spot, we were showing him how to use the touchscreen features, when the car shut off. After a little while of exploring the features, my brother opened his passenger door and got out. My father opened his door and proceeded to get out when the car started up and took off!!! Enough time had elapsed from when the engine shut off, that he forgot he didn't shut the engine off. This is a huge safety issue!!! I would like to comment that RAM (Chrysler) vehicles will not move if the doors are open and GM had better reconfigure their vehicles before they get sued!!! If my father had fallen from the vehicle and gotten run over, we'd be very rich right now, but I would never want him to get injured. That's why I'm posting this!
Amy P.
I have not heard of this happening before but can see how it could. Stress to him to put it in park immediately when stopped and it's a good idea to set the emergency brake also.

This is an aftermarket device to disable it:


Glad everything turned out ok.

Jerry Reynolds
The car took off? How? I have been using start stop for years and to "restart" from stop your foot has to be on the gas. Makes me wonder if his car is defective?
Besides not noticing he didn't turn the truck off, he might also have not put the transmission in PARK. Then when he took his foot off the gas to get out, the engine started and began to move.
On my 2018 GMC Terrain, all you have to do is take your foot off the brake and the car starts back. This is a super annoying feature and I could definitely see the car taking off if you're not careful. What makes me extremely mad is I might be getting ready to back up and the engine shuts off. Or I'll be at a complete stop and the person behind me might not be paying attention and run in to the back of me. That does scare me. All cars should have been made with a disable switch.
The Car Pro
I agree and have been saying this on air for few years. When you come to a stop, you can shift into low gear to disable, then shift back to drive when you start rolling.

Jerry Reynolds
Carolyn Fisher
I own a 2016 Chevy Malibu with the stop/start engine. I have had it back to my Chevy dealer because the stop/start will NOT disengage. Each time they would "work" on it to get it working. This went on for 4 visits! Last visit on February 7, 2019 the car was out of warranty and the bill was $386.00 but they gave me a 50% discount because it was happening when car was still under warranty. What they did was reprogram this system . Now, April 4th, it"s happening again

I want someone to tell me what could be wrong and how to fix it! Also. I would like to know if the transmission and engine is being damaged by my continue to drive it. Honestly, I would prefer it didn't work because it drives me crazy!!! I'm a 78 year old single woman and not financially secure to trade this car in.
Amy P.
Carolyn, I would call the Service Manager at your dealership and get him or her involved. They should fix it again with no charges to you since you paid the last time. They are missing something, hopefully the Service Manager can assist.

There is no evidence yet that the system is harmful to engines or transmissions, it's just annoying.

Good luck!

Jerry Reynolds
I would put a disable stop/start switch on your car, Ebay sells them for some vehicles.
If they can't fix the same problem in 3 tries, the car come under the lemon law. See an attorney.
l had some stopping problem when l stop at the red light my engine stop when my foot is on the brake when l took my foot off it starts again l checked the manual and it was explained that it is a new concept in the US it was very helpful now l know the reason for that it is to save fuel,which is great,

Ken I am getting good reports on a disable device at www.4dtech.com. If you can this for $100, I think it is money well spent.

Jerry Reynolds, President
Car Pro Radio Network


ok THE IDEA THAT THIS STOP/START FEATURE SAVES ON FUEL IS UTTER NONSENSE SINCE IT COST MORE TO TURN THE CAR OFF AND RESTART IT THAN IT DOES TO LET IT IDLE FOR THE SHORT PERIOD OF TIME IT IS OFF. sorry for the cap locks. I have a 2018 Chevrolet Equinox and the problem with the auto/stop feature is 90% of the time it does not work as designed and there are other times that the car stutters when stopped cause it does not auto stop. they have reprogrammed it twice with no change the car is starving for fuel and not shutting off and that too will waste fuel. There is no way to disable the feature on the 2018 models I am told or trust me that would have already happened as the feature is the dumbest thing ever designed on a vehicle. It never shuts off when the AC is on no matter what I have read here and another thing is a bigger battery means more money to replace it when the feature ends up killing it and the same with the starter so therefore I have had it with Chevrolet/GM and I worked for them until I got tired of being laid off every other month and took a buyout. the Dodge Journey is a much nicer SUV and I believe I have owned my last Chevrolet due to the stupidity of this feature and the Dealerships inability to FIX the problem of it not working and telling me it works properly...I am not stupid I was a certified Mechanic before becoming disabled and I know for a fact they do not make money fixing cars under warranty so they just say it works fine!

There is an aftermarket bypass module that plugs in under the hood. No splicing required, plug and play. This should an option from the car manufactures.