TPMS System Q&ATire Rotation Q&ASpark Plug Q&AWinter Tires Q&A

My TPMS Light Is On, What Does It Mean?
— Wondering What to Do About It

tpmsBerning’s Auto Repair Answer:

If your TPMS light is on, it means that one or more of your tires has low air pressure. The dashboard warning light, which looks like a cross-section of a tire with some lines in it, comes on when the tire pressure is 20% below what the auto manufacturer recommends. So if your recommendation is for 35 psi (pounds per square inch), the light will come on when your pressure falls to 28 psi.

It’s vital to note that 20% below recommended pressure is significantly under-inflated. This means that you will be experiencing degraded handling and that your tire will be running hotter than it should. This can not only be a safety hazard, but your tires will wear prematurely and could even suffer a heat related failure.

Even though the idea is a great concept, in reality, drivers should not use their Tire Pressure Monitoring System (TPMS) warning light as their trigger for checking their tire pressure. They should still check their tire pressure at least once a month.

Some TPMS systems indicate tire pressures for individual wheels which will indicate which tire is low – as long as the system has been reset after rotating the tires. Other systems will simply give a warning and it is up to you to check all your tires (including the spare). For more information, talk to your friendly Berning’s Auto Repair service professional.

You TPMS does not have a regularly scheduled maintenance interval. However, be aware that the batteries in the sensors mounted in each wheel will eventually die, illuminating the warning light and necessitating replacing the sensor. Sensors can also be damaged by road salt and other contaminants.

The automotive professionals at Berning’s Auto Repair in St. Michael recommend that you have your tire pressure checked at least once a month to maintain your safety and increase tire life.


How do I know when I should get my tires rotated and balanced?
— Good Question on Regular Vehicle Maintenance

18Berning’s Auto Repair Answer:

The interval for tire rotation could depend on a recommendation from either the tire manufacturer or the vehicle manufacturer. The interval is typically around 5,000 miles but could range from 3,000 to 8,000 miles. The background question for vehicle owners is why do tires need to be rotated?

Front tires wear differently than the rear tires because steering wears the shoulders faster up front. Rotating the position of the tires allows for more even wear among all the tires. Now the suspension set-up on certain vehicles may also affect the relative wear between the front and rear. There are several rotation patterns – your friendly Berning’s Auto Repair service professional will see that you get the correct pattern for your particular vehicle.

Wheels and tires are not perfectly balanced due to slight variations in the manufacturing process and the placement of tire pressure monitoring sensors. So weights are strategically placed on the wheel to ensure that the tire spins true. When a wheel is out of balance it is essentially bouncing thousands of extra times every mile. Now this can result in an uncomfortable vibration for drivers and passengers in the steering wheel or through the seats. An unbalanced tire will also wear quicker and it is hard on your shocks and struts.

You should have your wheels balanced if they detect a vibration or uneven wear. A wheel balance check every year is a good idea. Because tires cost so much, it’s a great idea to do everything you can to make them last as long as possible. Proper tire inflation, regular tire rotation and wheel balancing are important keys to long tire life. The team at Berning’s Auto Repair in St. Michael can survey your tires for signs of uneven wear and diagnose and correct the problem.

I’m confused about when I should get my spark plugs replaced. What’s the deal?
— Charged Up

Answer from Berning’s Auto Repair:

Well it can be confusing for drivers because there are several types of spark plugs and some last longer than others. Your owner’s manual will have a recommendation for when your spark plugs should be changed.

Here’s a little background from Berning’s Auto Repair. Spark plugs are in the combustion chamber of your engine. They send a little spark between two electrodes at the end of the spark plug which ignites the gasoline. This little spark goes off thousands of times a minute. Over the miles, the electrodes on standard grade spark plugs wear away increasing the gap between them. When that happens, the spark isn’t as strong and the fuel doesn’t burn as well.

As I mentioned above, there are several types or grades of spark plugs. The standard grade is copper core. They are great for quick starts and may last 12,000 to 13,000 miles.

Single platinum spark plugs use platinum on one of the electrodes. These typically last 30,000 to 60,000 miles and have improved ignitability and performance. Double platinum plugs use platinum on both electrodes. This virtually eliminates gap erosion. They may last 60,000 to 100,000 miles.

Then there are the plugs that use iridium in their electrodes. These usually last over 100,000 miles. They are very durable and give premium performance and improved fuel efficiency.

Now it’s essential that motorists always use at least the grade of spark plug that originally came on their vehicle. This makes sure that your spark plugs are up to delivering the performance and fuel economy your vehicle was designed for. Of course, you may upgrade your spark plugs for better durability and performance. Talk with you friendly Berning’s Auto Repair service specialist about how you want your vehicle to perform and let us help you select the spark plug that best suits your needs.

What is the benefit of winter tires?
— Slippin' & Slidin' Through Minnesota Winters

Berning’s Auto Repair Answer:

This is a really good question. Most new vehicles come with all-season tires that work pretty well in our climate, and the winter conditions many drivers encounter. First, let’s talk about the things that dedicated winter tires do really well, touch on all-seasons and then you should have some information to help you in your tire selection.

The first thing about winter is that it’s cold. The rubber compound used in summer and all-season tires gets a bit hard when MN temperatures drop below 45 degrees Fahrenheit. Winter tires, on the other hand, stay more pliable as the thermometer drops in here in Minnesota. This means better dry road traction in the cold.

Ice and snow is the next thing drivers worry about during Minnesota winters. Extreme winter condition snow tires have a tread design that cuts into and expels deep snow for maximum traction. These tires have a mountain and snowflake icon on the sidewall of the tire.

If you live where the ice and snow are more moderate, you can still benefit from winter tires. Their tread has many small “cuts” called sipes that really help them get a grip on ice.

Now, all-season tires are a year-round compromise between high summer performance and high winter performance. They just don’t handle either extreme as well as do dedicated summer or winter tires for Minnesota driving. For example, winter tires offer 25% to 50% more traction than all-season tires. And studies have shown that all-season tires can take upwards of 40% longer to stop than winter tires. This could be enough difference to prevent getting stuck or in an accident.

So what’s best for you? Talk to us about the conditions in which you drive in Minnesota
throughout the year and how essential performance is to you. For many local vehicle owners that put a premium on handling performance, dedicated summer tires in summer and dedicated winter tires in the winter (for cold as well as ice and snow) are what they need to satisfy their performance needs. Berning’s Auto Repair will mount different tires depending on the season, and some vehicle owners will stock themselves up two sets of tires and wheels, one for summer, one for winter.

Your friendly Berning’s Auto Repair tire professional can help you decide on a great all-season tire if that is what best suits your needs. No matter which route you take, remember that quality tires are not immune to the laws of physics – so it’s key to drive safely in all Minnesota road conditions.