Is It Illegal to Warm Up Your Car in Minnesota?

Is Warming Up Your Car Illegal in Minnesota?

The answer depends on where you live. There is no statewide Minnesota law that generally prohibits leaving your car running or idling while unattended. However, many cities have local ordinances that restrict this practice.

Why do these laws exist? Primarily to prevent vehicle theft. During Minnesota winters, car thieves look for running vehicles with keys inside, which they can steal in seconds. In recent years, Twin Cities law enforcement has dealt with spikes in vehicle thefts, with the common thread being unattended, running vehicles.

While enforcement varies by community, violations can result in tickets and fines. One Michigan resident made national news after receiving a ticket for warming up his car in his own driveway under a similar local ordinance.

City-Specific Ordinances: Know Your Local Rules

Several Minnesota cities have restrictions on leaving an unattended vehicle idling.

Minneapolis

Minneapolis has an anti-idling ordinance that limits most vehicles to 3 minutes of idling in any 1-hour period. Violations can result in fines up to $200. There are a few exceptions to this rule. For example:

• Vehicles may idle when stopped in traffic.
• When temperatures drop below zero or rise above 90 degrees, the idling time limit is extended to 15 minutes.
• An occupied vehicle with a sleeper compartment may idle during a rest or sleep period.
• A passenger bus may idle a maximum of 15 minutes while non-driver passengers are on board.
• Emergency vehicles, such as police vehicles, ambulances, and fire trucks, may idle longer.

Notably, this ordinance applies even on private property, such as a driveway.

The City also requires that if keys are in the ignition on a city street, parkway, or alley, the driver must be inside the car or in "physical control" of it (standing close enough to respond if needed). This requirement applies only to public streets, parkways, and alleys. On private property like your driveway, you can leave your car running with keys in the ignition, though the three-minute idling limit still applies.

St. Paul

St. Paul does not have a specific anti-idling time limit ordinance. However, a city ordinance requires that anyone leaving a motor vehicle unattended on any street, alley, or parking lot must "lock the ignition, remove the key and take it with him or her.” Violating this ordinance could result in a ticket.

This ordinance directs police officers who discover keys in the ignition of an unattended vehicle (running or not) to remove the keys and deliver them to the desk officer at the central police station.

Rochester

In Rochester, City Ordinance 11-6-9 makes it illegal to park a vehicle on a street or alley with the vehicle running unattended. Just as in St. Paul, the ordinance states that drivers must lock the ignition, remove the key, and take it with them.

St. Cloud

St. Cloud has no general regulation restricting idling and warming up. However, local police still advise against it due to the risk of theft.

Bloomington

Bloomington's City Ordinance § 8.14 requires that drivers remove keys from the ignition when leaving a vehicle unattended anywhere in the city. This regulation applies to cars parked on private property, as well. However, this requirement doesn't apply if the windows are closed and doors are locked, or if the vehicle is inside a building. It also doesn’t apply with a remote starter, since the keys aren’t in the ignition.

Unlike Minneapolis, Bloomington has no specific time limit on idling. This means you can warm up your car with a remote starter without restriction, and you can even warm it up with keys in the ignition if your doors are locked and windows closed.

Duluth

Duluth City Ordinance 33-91 prohibits leaving a vehicle unattended with keys in the ignition. As in St. Paul, if a police officer finds such a vehicle, they are instructed to remove the keys and deliver them to police headquarters. This ordinance applies only to vehicles parked on a “street, alley, used car lot, or unattended parking lot,” so a car on private property is exempt and may be left idling.

Lakeville

Lakeville City Ordinance 6-1-3 prohibits leaving a motor vehicle parked on public streets with the key in the ignition. This restriction does not apply to private driveways or private parking lots.

Does Your Car Need to Be Warmed Up?

Regardless of the law in your city, does warming up a car actually help anything? The truth is, your car probably doesn't need to warm up at all.

The Old Days vs. Today

Older cars with carburetors (generally pre-1990s vehicles) did need to warm up. Without warming, the carburetor couldn't get the right mix of air and fuel to the engine, and the car could stall. These vehicles genuinely needed several minutes of idling before driving.

Modern fuel-injected engines (virtually every car since the mid-1990s) have electronic fuel injection systems that automatically provide the optimal mix of fuel and air to the engine, regardless of temperature. These systems use multiple sensors to adjust instantly to cold conditions.

The Minnesota Pollution Control Agency confirms: unless you're driving a vintage vehicle, warming up is no longer necessary for the engine's sake.

How Long Does Your Car Need to Warm Up?

According to AAA and automotive experts, a modern car only needs 30 seconds to one minute of idling when you start it. That’s it. In the time it takes you to buckle your seat belt and adjust your mirrors, the oil circulates fully through the engine. After that, the engine is fully lubricated and ready to go. In fact, the engine warms up faster while driving than while idling.

So what’s the right way to warm up your car?

1. Start your engine and let it idle for 30 seconds to 1 minute
2. Drive gently for the first 5-10 minutes at residential speeds.
3. Avoid hard acceleration or high RPMs until the engine reaches operating temperature.

Not only is this approach more efficient, but it also uses less fuel than letting your car idle.

Why Long Idling Actually Harms Your Engine

• Fuel System Damage: When your engine idles in cold temperatures, it runs in a gasoline-rich mode. The excess gasoline can wash oil off cylinder walls and pistons. Because your engine is cold, the oil doesn't flow well enough to replace what's been removed. Over time, this causes engine performance to degrade and reduces fuel economy.
• Oil Dilution: The rich fuel mixture can cause gasoline to bypass the pistons and mix with your engine oil, diluting it. Diluted oil has a thinner consistency and weaker protective film, leading to increased wear and faster oil breakdown.
• Wasted Fuel: Extended idling wastes significant fuel. According to the U.S. Department of Energy, drivers waste about three billion gallons of fuel every year by idling.

What Actually Helps Your Car in the Minnesota Cold

Instead of long warm-up periods, here's what genuinely protects your vehicle:

1. Use a Block Heater: A block heater keeps your engine block, coolant, and oil warm while plugged in overnight. This handy device reduces engine wear from cold starts, improves fuel efficiency, and reduces emissions. However, you will have to plug it in two to three hours before you plan to drive.
2. Check Your Battery: Cold weather is brutal on batteries. Have yours tested before winter and replace it if it's more than three years old.
3. Use the Right Oil: Synthetic oils rated for low temperatures (like 5W-30 or 0W-20) flow better in cold conditions and provide better protection during cold starts.
4. Keep Your Gas Tank at Least Half Full: This prevents fuel line freeze-ups and gives you a safety buffer if you get stranded.
5. Clear Your Exhaust Pipe: Before starting your car, check that snow or ice isn't blocking your exhaust pipe. A blocked exhaust can cause carbon monoxide to enter your vehicle's cabin.

Why You Should Never Warm Your Car Up in a Garage

No matter what the law says, you should never idle your car in a garage, even with the door open. Research on carbon monoxide dangers in garages shows serious risks:

• According to Iowa State University research, running a vehicle in an open garage for just two minutes can raise carbon monoxide (CO) concentrations to dangerous levels.
• The same study found measurable CO remained in the garage hours after removing the car.
• In a closed garage, CO concentrations can reach life-threatening levels in minutes.
  

Studies have even shown that air from attached garages can flow into homes, especially during winter when houses are sealed up. Carbon monoxide from a running vehicle can enter your living space, often in concentrations too diluted to trigger your indoor CO detector, but still dangerous over time.

Staying Warm Without Warming Up Your Car

Of course, the real reason many Minnesotans warm up their cars isn't that they think the engine needs it. It's because stepping into a frozen car at 6 AM when it's -10°F outside is miserable. Numb fingers on the steering wheel, breath fogging up the windshield, and shivering for the first ten minutes of your commute isn't anyone's idea of a good time. Fortunately, there are better ways to stay warm than long idling sessions.

Counterintuitively, driving your car warms the cabin faster than letting it idle. When the engine is under load (actually driving), it heats up more quickly, which means hot air from your heater arrives that much sooner. Of course, a car equipped with heated seats and steering wheel can help ward off the cold.

Warming Up Your Car: Is It Really Worth the Hassle?

The next time you're tempted to let your car idle for ten minutes on a freezing morning, remember: Those old habits were built for old technology. Modern cars are engineered for quick starts and gentle driving, not extended warm-ups.

And while the laws vary across Minnesota cities, the science doesn't. Whether you’re in the Twin Cities or anywhere else, the best approach is generally the same: start your car, buckle up, and go. Your engine will thank you, your wallet will thank you, and you'll always be on the right side of both the law.

When Winter Driving Goes Wrong in Minnesota

Even the most careful Minnesota drivers can find themselves in difficult situations during winter weather. Whether it's black ice, poor visibility, or another driver's mistake, winter accidents happen.

If you are injured in a winter car accident in Minnesota, SiebenCarey is here to help. With offices in Minneapolis, Lakeville, and Duluth, our experienced personal injury attorneys understand Minnesota law and have been fighting for injury victims' rights for over 70 years. We can help you:

• Understand your rights after an accident
• Navigate insurance claims
• Get the compensation you deserve for medical bills, lost wages, and pain and suffering
  

Schedule a free consultation today, and we can answer all your questions.

FAQs

Can I get a ticket for warming up my car in my own driveway in Minnesota?

It depends on your city.

• In Minneapolis, the three-minute anti-idling rule applies everywhere in the city, including private driveways. Violations can result in fines up to $200.
• In St. Paul, there is no anti-idling rule. However, a city ordinance requires you to remove keys from unattended vehicles on public streets, alleys, and parking lots, but not private property. Thus, you can warm up your car in your driveway in St. Paul. 

Most other Minnesota cities have no restrictions on warming up your car on private property.

What happens if I get caught warming up my car illegally?

Penalties vary by city.

• In Minneapolis, you could face fines up to $200 for violating the anti-idling ordinance.
• In St. Paul, you may be fined for leaving your vehicle unattended and running on a public street. The police may also confiscate your keys and require you to pick them up at the police station.
• In Rochester, you could receive a citation for violating City Ordinance 11-6-9.
  

Most officers view this as a minor violation and may issue warnings rather than tickets, especially for first-time offenders.

Does idling my car waste gas?

Yes, extended idling wastes significant fuel. For your wallet and the environment, it's better to start your car and drive away gently after 30–60 seconds of idling.

Should I warm up my car in my garage with the door open?

Even with the garage door open, dangerous levels of carbon monoxide can build up in just two minutes. Iowa State University research found that CO levels remained measurable in garages for hours after a car was removed. The lesson here: Avoid idling your car in a garage, even briefly.