Active Fuel Management
March 27, 2025
What is AFM? – Active Fuel Management (AFM)
Active Fuel Management (AFM) is a technology developed by General Motors (GM) designed to improve fuel efficiency in certain engines. It works by deactivating half of the engine’s cylinders when full power isn’t needed, such as during highway cruising or light acceleration. This helps reduce fuel consumption by using fewer cylinders, and then reactivating them when more power is required, like during heavy acceleration. AFM is typically found in V6 and V8 engines, providing a balance between performance and fuel efficiency.
While Active Fuel Management (AFM) can improve fuel efficiency, it can come with issues, including:
- Lifter and Valve Train Wear: The AFM system relies on deactivating and reactivating cylinders, which puts additional stress on the lifters and valve components. Over time, this can lead to premature wear and potential engine noise or even failure of the AFM components.
- Oil Consumption: AFM can cause increased oil consumption in some engines. This happens because the lifters used in the AFM system may not seal perfectly, allowing oil to escape into the combustion chamber, which can lead to engine knocking or damage over time.
- Activation/Deactivation Issues: The system’s transitions between active and deactivated cylinders need to be smooth, but sometimes the transitions can cause hesitation, rough idling, or a noticeable change in engine performance. This can be frustrating for drivers who notice it.
You might ask, what can I do to help prevent such issues from happening? To try and help ensure that your engine runs as smoothly as possible, stay on top of regular maintenance. Because AFM can increase oil consumption, regular oil changes with high-quality oil will help keep the engine lubricated properly. With that being said, it won’t hurt to monitor oil levels as well by checking the oil level on the dipstick. If you do hear unusual engine noise or have a check engine light on, do not let it linger. Take it in to get it looked at. The longer you wait, the more costly it could become.
What vehicles are affected by AFM and how do I know if my GM vehicle has it? GM (General Motors) products are most notoriously impacted by AFM. These include Chevrolet, GMC, Cadillac, and Buick, primarily with V8 and V6 engines. Most often found in larger, more performance-oriented, fuel-hungry vehicles such as trucks and full-size SUVs where it helps improve fuel efficiency. To know if your vehicle has AFM, you can check the engine specifications in the owner’s manual or consult with your local mechanic.
As the temperatures drop and winter sets in, many drivers start experiencing frustrating car issues that seem to appear out of nowhere. At PROFIX Auto Repair, we've seen a surge in these cold-weather-related problems every year. The good news? Most of them are preventable with a little preparation and maintenance. In this post, we'll cover the most common issues our customers bring to us during the winter months and share tips on how to avoid them. 1. Dead or Weak Battery - Cold weather is the number one enemy of car batteries. Low temperatures can reduce a battery's power by up to 50-60%, making it struggle to start your engine—especially if it's already a few years old. Tip: Get your battery tested for free at PROFIX—we can tell you if it's time for a replacement before you're stranded. 2. Low Tire Pressure - For every 10°F drop in temperature, your tires can lose about 1 PSI of air pressure. Under inflated tires reduce traction, fuel efficiency, and increase the risk of blowouts on icy roads. Tip: Check your tire pressure monthly (including the spare!) and inflate to the manufacturer's recommended levels. 3. Thickened Engine Oil - In extreme cold, conventional oil can thicken, making it harder for your engine to turn over and potentially causing unnecessary wear during startup.firestonecompleteautocare.com Tip: Switch to a lower-viscosity synthetic oil rated for winter conditions. An oil change at PROFIX can make a big difference. 4. Frozen Door Locks and HandlesMoisture gets into locks and seals, then freezes solid, leaving you locked out of your own car. Tip: Apply a silicone-based lubricant to locks and rubber seals to prevent freezing. 5. Wiper Blade Issues - Wiper blades can freeze to the windshield, become brittle, or get damaged by ice buildup, streaking or failing when you need clear visibility the most. Tip: Replace old blades with winter-specific ones and lift them off the glass when parking in snow. 6. Reduced Traction and Getting Stuck - Snow and ice turn roads into skating rinks, leading to skids or wheels spinning without forward progress. Tip: Consider winter tires for better grip, and keep a traction aid like kitty litter in your trunk.Don't Wait Until It's Too Late!Many of these issues can be caught early with a simple winter maintenance check. At PROFIX Auto Repair, our experienced technicians are here to help keep your vehicle running smoothly all season long. Schedule your winter prep appointment today—call us or book online. Stay safe and warm out there! PROFIX Auto Repair – Your Trusted Local Experts for All Seasons
Well, Norman, Oklahoma decided to sprinkle a little Christmas magic on us in December, and by “sprinkle” we mean actual snowflakes the size of tortillas! While the kids are building wonky snowmen and half the town is attempting donuts in the Dollar General parking lot, we’re over here thinking about your poor car shivering outside.Here’s the quick, fun PROFIX Snow-Day Survival Guide:Slow Your Roll, Cowboy – Black ice doesn’t care how tough your truck looks. Ease off the gas, increase following distance, and pretend you’re driving Miss Daisy. Brakes Aren’t Suggestions – Pump those brakes gently like you’re flirting, not stomping like you just saw your ex at Target. Wipers Up, Problems Down – Before the snow hits next time, flip your wipers up. No more doing the ice-chip shimmy at 6 a.m. with a cereal bowl in one hand. Battery Hates the Cold More Than Your Mother-in-Law Hates Your Cooking – Cold weather can sap 50% of your battery’s cranking power. If your car’s been starting slower than a Monday morning, swing by PROFIX. We’ll test it faster than you can say “hot cocoa.” Tires Matter, Bro – If your tread looks slicker than the roads, it’s time for new shoes. All-seasons are cute until they’re ice-skating. Bonus laugh: Yes, someone already brought us a car this morning because “the traction control light looks like a sad face.” It’s okay, we speak fluent car emotions.Stay warm, stay safe, and if your car starts making noises that sound like it’s auditioning for a polar bear documentary, you know where to find us—we’re the warm shop with the coffee that doesn’t taste like regret.Drive slow, Norman. We love you (and your car) too much to see either of you in a ditch.— The PROFIX Crew
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Hey PROFIX Auto Repair family! At PROFIX, we're all about keeping your rides running smoothly so you can focus on what matters most. But did you know we're also passionate about lifting spirits—and sometimes even people—through the skies? We're proud to support Angel Flight , a nonprofit that provides free private flights to patients and families facing medical challenges. These compassionate pilots volunteer their time, planes, and hearts to connect folks with life-saving care they couldn't otherwise reach. It's public benefit flying at its finest, turning miles into hope! That's why a portion of our profits goes straight to Angel Flight. And here's the best part: Our owner, Philip, is an Angel Flight pilot himself! He logs those volunteer hours in the cockpit, personally flying missions that make a real difference. Every oil change, brake job, or tune-up you trust us with helps fuel their missions—and Philip's wings. Together, we're not just fixing cars—we're fueling kindness. Next time you're in for service, ask us more about Angel Flight . Let's keep the good vibes rolling! #PROFIXAutoRepair #AngelFlight #WingsOfHope #GiveBack
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