Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum - View Single Post - Snow driving weather
View Single Post
Old 01-05-2013, 08:18 PM   #9
Focus Enthusiast
dodgeguy's Avatar
Join Date: May 2011
Fan#: 85952
Location: Sterling Heights, MI
What I Drive: 2014 White Focus ST2

Posts: 285
Points 634, Level 12
Points: 634, Level: 12 Points: 634, Level: 12 Points: 634, Level: 12
Level Up 68% Completed
Level up: 68% Level up: 68% Level up: 68%
Forum Activity 1%
Activity: 1% Activity: 1% Activity: 1%
FF Reputation: 1 dodgeguy Good Standing Member
Buy-Sell-Trade Rating: (0)
Originally Posted by zehkaiser View Post
I wouldn't keep it in a low gear all the time. Try to keep your RPMs as low as possible while doing anything in a low traction situation. Let me try to explain a little bit that will hopefully shine some light on suggested driving during poor conditions.

The coefficient of friction on snow is usually between 0.3 - 0.6. This is much lower than the coefficient of friction on dry asphalt, which is usually about 0.9. Every action you take in a FWD car 'uses' some available friction from your front tires on the surface you're driving on. That means that if you're turning WHILE braking or accelerating, you have a greater chance of losing traction. Because you're in a FWD car, all force from the engine will also be on your turning wheels. Using the brakes instead of your engine will put ~70% of the stopping force on your front tires, and ~30% on your rears. Your hand brake will be 100% braking from the rear tires.

So to get back to driving on snow, if you're driving in 2nd gear at 25 mph on snow, you're probably around 3k rpms. If you try to make a turn and you let off the gas to do it, you're going to cause the engine to slow the front tires. This uses some of your 'available' friction. Begin turning, and it'll use more. Try to turn too hard, and you're gonna slip.

The best method for driving where traction is an issue is to reduce the overall forces on your tires. Don't turn sharply, don't accelerate/decelerate quickly, and take your time getting places. Oh, and look out for the idiots who will slide right out in front of you because they were going to fast.

Also, don't try to stop using the hand brake. It's much different from using the pedal, and you can easily lock up your rear wheels.
Man, I love the techie! I thought the handbrake was for doing powerslides! LOL :)
dodgeguy is offline  
    Reply With Quote