Tech Tip Tuesday: Should you let your car warm up?

This may seem like an odd topic to cover during this time of year when most of you are experiencing mild to warm weather, but warming up your car isn’t just for the chilly months. If you’re like most people, you may let your car warm up when it’s cold outside to clear the windshield for safety and warm the cabin for comfort. That all makes sense, but how does the engine feel about all this?

I’ll cover three general temperature ranges, all assuming a “cold start” – this means that the vehicle hasn’t run in several hours and the engine is at or near the ambient temperature.

The cold (ambient temp) start: temps are well below freezing. When Jack Frost settles in for a while, it’s best to let your car warm up for a minimum of 30-60 seconds to allow the oil to begin to warm up and thin a little. You can let your car warm up for 10-15 minutes in order to clear the windshield and warm the cabin, but most cars can knock the chill off in about 2-3 minutes unless it’s just a bitter cold morning.

The mild start: temps are 40-60 degrees. Think a crisp fall morning where you might don a light jacket or a sick Thundercats windbreaker. Mild temperatures like these don’t require a long warm up time for the driver, but the engine still needs a minimum of 15-30 seconds to get oil everywhere it needs to be to protect the engine properly.

The warm start: temps are 80+. You’ve just completed another grueling day at the office, shop, store, etc. and you come out to race home and beat the traffic. Hold up just a second! Even though the inside of your car could bake cookies, your engine still needs at least 10-15 seconds to warm up.

Most vehicles have a “fast idle” where they will idle above the normal 600-700 RPM speed while they’re warming up. If you’re unsure of how long to warm up, let your car tell you. When the idle settles below 1000 RPM or so, you should be good to go.

Why warm up? Think of it this way: you get out of bed and go for your morning run. Do you jump out of the bed and immediately hit a full on bear-chasing-me-through-the-woods sprint? I sure don’t! You’d pull more muscles than you knew you had if you did that. Your vehicle is the same way. It needs some time to collect it’s thoughts, wake up, decide where it’s going… Ok, but seriously, the engine is designed to run at 200+ degrees and if you jack-rabbit away, you put a lot of unnecessary wear on an engine. Most engine wear happens at start up when oil pressure is non-existent and the engine is cold and tight.

What do YOU do when you start your car? Do you blast a power-up song before your commute? “Eye of the Tiger” anyone? Let me know in the comments section below. Happy wrenching!

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