Poll

What would you write on a dirty car?





Show Results

Poll

What would you write on a dirty car?





Show Results

Hydroplaning: The Physics of Ending Up in a Ditch

by Mac Demere on Friday, January 14, 2011 05:41

The reason you said, “Oh, Fudge!” or similar when you drove into that big puddle (and maybe even spun out or plowed straight off the road) is that water is not compressible. Unlike air. Air can be compressed, and for that we can thank it for football, basketball, and, especially, women’s beach volleyball. When you hit that puddle, you felt as if you had no control of your car. And you didn’t.

Water must be pushed aside or it will lift heavy objects off the ground. How much weight can water lift? Denver’s old Mile High Stadium used water to support half its grandstands so they could be slid from football to baseball configuration and back.

If water can lift half of a sports stadium, it’ll have no trouble lifting your 3,500-pound car off the road. “Off the road” as in “nothing is touching the ground.” “Off the road” as in “you have as much control as a fisherman in a flat-bottom boat without a rudder or oars on a fast-moving stream.”

When you drive into deep water, the water has two choices. First, it can be channeled through the grooves and such on you tires. Second, it can lift your car off the road. (Tire nerds are saying, “That’s not EXACTLY correct.” There is a step between those two states. Okay. It’s called viscoplaning: The water lifts up portions of individual tread blocks. Happy nerds?) More...

Tags: ,

Electronic Stability Control: When It Comes On Do Nothing

by Mac Demere on Tuesday, December 7, 2010 03:45

If the electronic stability control system in your car engages, you’re best bet is to do nothing. Anything you do is probably going to be wrong. Or futile.

That was prompted by a question from a reader from Milwaukee in response to one of many articles I’ve written about ESC, which is called a variety of names by different manufacturers. (If you just moved from Manhattan to America and are learning about “cars” for the first time, ESC uses a computer to sense that your car is about to spin out or plow straight off the road. Then it does magical stuff with the brakes and engine in a not-always-successful attempt to save you from your dumb, no-drivin’ self.)

“My wife went out to run errands on the snowy suburban streets. She returned and described the sounds and warning lights that were being generated by the (ESC) and traction control, and ABS.

“In the past we drivers were always taught to steer into a skid. My question, is this still the case when driving a car with a system like (ESC)?” More...

Tags: , , ,

Why People Drive Like Idiots in the Rain

by Mac Demere on Friday, December 3, 2010 03:03

When it rains, why do people drive like idiots? Drivers run traffic lights, fail to wait for a safe gap to pull into traffic, make erratic or inexplicable lane changes, and drive either far too fast or way too slow. (Take “People” and “drivers” to mean to “you.”)

At the turn of every season, motoring clubs and various “experts” send out press releases telling you how to prepare for the upcoming inclement weather. (I picture people reading these: “The weather is going to change? It might rain, get cold, or SNOW? THAT’S never happened before!”)

The well-meaning folks from the auto club, and car writers trying to satisfy editors who just heard Christmas music in a store, pull out the old stand-bys: Check your battery, assemble a survival kit, and take your vehicle in for a checkup. If the group or writer has a lick of sense, they also hit on the two reasons people drive like nuts in the rain: windshield wipers and tires.

Rubber components are like people: They die even if they haven’t gone very far or done very much. A one-year-old wiper is like an 80-year-old man. If you can’t remember when you last replaced your wipers, you need new ones. Top-quality auto parts stores will replace your wipers for no extra charge. Also, use a water-shedding product, either applied directly to the windshield or in the washer fluid. More...

Tags: , , , ,

Driving with Electronic Stability Control

by Mac Demere on Tuesday, October 12, 2010 02:30

The world’s best driving instructor rides with you every day. You ignore it. Your digital driving instructor is the computer that controls your anti-lock brakes and, if you have a newer, or higher-end car, electronic stability control (ESC).

A professional racecar driver can lap a road-racing course track (left and right turns) almost as fast with ESC operational as he can with it disengaged. A pro almost never triggers ABS. (There are exceptions: Mercedes’ ESC is extremely invasive.)

Smoothness is the reason the pro driver can avoid engaging ESC or ABS. The pro driver is allowing the car to do the work. He’s not attempting to force it to submit to his will. More...

Tags: , ,