Holding On The Road: Driving Lesson Myths

  • Thread starter Yoni
  • Start date
In summary: The gear has nothing to do with how the tyres hold the road so I have no idea what the teacher was getting at.
  • #1
Yoni
65
1
When I started taking driving lessons a long time ago, my teacher told me that when putting the gear into neutral it diminishes the car's hold on the road. Is it actually true?
The tires "hold" the road through static friction, which has a maximum value of mu*N. Does the gear directly affect mu, which should depend only on the contact area and kind of tire and road? Maybe he simply meant that letting the car accelerate downhill on neutral would increase the centrifugal force needed for a fast turn, which might be higher than the maximum friction allowed.
 
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  • #2
The gear has nothing to do with how the tyres hold the road so I have no idea what the teacher was getting at. The only thing going into neutral when you drive does is eliminating engine braking.
 
  • #3
Yoni

By 'Hold' your instructor meant keeping the car on the intended route.

Try this experiment.

Hypothisis - Tyre grip is not affected by gear engagement during high speed negotiation of road bends.

Method

1) Find a road with a long tightening bend. Approach it a 60miles an hour and slip into neutral just as you enter the bend.

When you come out of hosptial and recover your vehicle from the body shop try part 2.

2) Approach the bend at 60MPH use the appropriate brake, gear change, accelerate sequence.

Results

Analyse and evaluate the difference betwen the two.

Did you reject the null hypothisis?

Is there a statistically significant difference between 1 and 2,

Is there a clinically significant difference

Discuss the merits and limitations of different driving protocols, how will this affect future driving experience.

Conclusion

Listen to the driving instructor

LoL Dave :smile:
 
  • #4
Yoni said:
When I started taking driving lessons a long time ago, my teacher told me that when putting the gear into neutral it diminishes the car's hold on the road. Is it actually true?
No it's not true. All this does is disconnect the engine from driven tires, eliminating engine induced acceleration or deceleration.

If anything, reducing the forward or rearward force at the contact patch on the driven tires, leaves more of the total grip available for cornering. For this very reason, almost all racing motorcycles, some street motorcycles, and some race cars, have slipper clutches that slip a bit during engine braking to reduce the engine braking force on the rear tire(s).
 
  • #5
david smith said:
Try this experiment.
Your experiment involved using the brakes. If you apply the brakes before entering a turn to reduce your speed, that's not the same as entering the turn at constant speed and also not the same as keeping the car in gear. It is the application of the brakes to reduce the speed so you can negotiate the turn that keeps you on the road, not the fact that the car is still in gear.

Your experiment is a non sequitur.
 
  • #6
Jeff Reid said:
If anything, reducing the forward or rearward force at the contact patch on the driven tires, leaves more of the total grip available for cornering. For this very reason, almost all racing motorcycles, some street motorcycles, and some race cars, have slipper clutches that slip a bit during engine braking to reduce the engine braking force on the rear tire(s).

Jeff, I agree with you completely, eliminating the force on the forward/backward axis leaves more space for friction on the radial axis, for turning. But I don't understand why is it important to reduce engine braking in the rear tyres specifically.

However, consider this hypothesis:
The gear induces only engine break that inhibits rolling of the tyres, which in turn reduce car speed by friction with the road. This deceleration would still be able to increase the maximum static friction through an increase in the area of contact between the road and the front tyres. Mostly the front tyres are important in turning, and the deceleration creates higher pressure on the front tyres (and less pressure on the rear tyres) which can increase the contact area and also the Normal force.
 

Related to Holding On The Road: Driving Lesson Myths

What is the most important thing to remember when holding on the road during a driving lesson?

The most important thing to remember is to stay calm and focused. Keep your hands at the recommended positions on the steering wheel and maintain a steady speed. Avoid sudden movements and remember to check your mirrors frequently.

Is it true that you should always hold the steering wheel at the "10 and 2" positions?

No, this is a common misconception. The recommended hand positions on the steering wheel are now at "9 and 3". This allows for better control and reduces the risk of injury from the airbag in case of an accident.

Do I need to grip the steering wheel tightly while driving?

No, gripping the steering wheel too tightly can actually lead to fatigue and muscle tension. It is important to have a relaxed grip on the wheel and use your arms and hands to guide the car in the desired direction.

Should I keep my foot hovering over the brake pedal at all times?

No, this is not necessary. Keeping your foot on the brake pedal can actually lead to unintentional braking and cause confusion for other drivers. Instead, keep your foot close to the pedal and only use it when necessary.

Is it true that you should always keep your hands on the steering wheel while driving?

Yes, it is important to keep both hands on the steering wheel at all times while driving. This allows for better control and reaction time in case of unexpected situations on the road.

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