3 ms·

Doesn't this stopping distance depend on the car? Said German cars have bigger breaks and bigger tyre surface and have been proven to stop quicker. Top Gear sho

Doesn't this stopping distance depend on the car? Said German cars have bigger breaks and bigger tyre surface and have been proven to stop quicker. Top Gear showed this often (Australian trip with the m6, Bentley and gtr) all stopping in less than half the Highway Code distance...)

tomatotomato37 8y ago
Yes, it matters enough that you should pretty much ignore any skid calculator without a weight component. Consumer reports even put together a list on which cars have the best "safety performance" that measured things like braking distance; the SUVs rank pretty hilariously https://www.consumerreports.org/car-safety/best-car-safety-performance/ https://www.consumerreports.org/car-safety/best-car-safety-p...
oppositelock 8y ago
Stopping distance does depend on the car, but physics has a bigger influence. The kinetic energy in a car is 1/2mv^2. No matter what car you're in, going twice as fast requires dissipating four times the energy in order to stop. So, take a sporty car with twice the braking performance of a basic car, and you can go 1.44x as fast as the basic car while still having the same stopping distance. I have a very light car that I use on the track, with an amazing amount of braking for its weight. Full deceleration happens at 2.5g, that's not pleasant. There are also comfort limits here.
- tiernano 8y ago
  Might not be pleasant but guessing hitting something would be less pleasant...
- boznz 8y ago
  Reaction time has an even bigger influence. Slower speed = more reaction time
  - KnightOfWords 8y ago
    Distance covered during reaction time scales linearly with speed, while distance covered under braking goes up exponentially.
Johnny555 8y ago
The 100 km/h stopping distance of a BMW M5 is ~30m, compared to 41m for a Honda Fit. https://fastestlaps.com/lists/top-quickest-stoppers-60mph https://fastestlaps.com/lists/top-quickest-stoppers-60mph That's a pretty good performance (but it's a $100K car), but at 200 km/hr, the stopping distance of the M5 increase to 124m (which makes sense since a 200 km/h car has 4X the kinetic energy of a 100 km/h car) Once out of the specialty racing cars, all of the cars "faster stoppers" list took about 27m-30m to stop from 100 km/h so that seems about the best that can be achieved today.
GorgeRonde 8y ago
Since cars and trucks weight vary highly, there is actually a norm that sets how big the breaks should be so that everyone has the same emergency halting distance. This diminishes the chances of a pile-up.

tomatotomato37 8y ago

Yes, it matters enough that you should pretty much ignore any skid calculator without a weight component. Consumer reports even put together a list on which cars have the best "safety performance" that measured things like braking distance; the SUVs rank pretty hilariously https://www.consumerreports.org/car-safety/best-car-safety-performance/ https://www.consumerreports.org/car-safety/best-car-safety-p...

oppositelock 8y ago

Stopping distance does depend on the car, but physics has a bigger influence. The kinetic energy in a car is 1/2mv^2. No matter what car you're in, going twice as fast requires dissipating four times the energy in order to stop. So, take a sporty car with twice the braking performance of a basic car, and you can go 1.44x as fast as the basic car while still having the same stopping distance. I have a very light car that I use on the track, with an amazing amount of braking for its weight. Full deceleration happens at 2.5g, that's not pleasant. There are also comfort limits here.

tiernano 8y ago
Might not be pleasant but guessing hitting something would be less pleasant...
boznz 8y ago
Reaction time has an even bigger influence. Slower speed = more reaction time
- KnightOfWords 8y ago
  Distance covered during reaction time scales linearly with speed, while distance covered under braking goes up exponentially.

Johnny555 8y ago

The 100 km/h stopping distance of a BMW M5 is ~30m, compared to 41m for a Honda Fit. https://fastestlaps.com/lists/top-quickest-stoppers-60mph https://fastestlaps.com/lists/top-quickest-stoppers-60mph That's a pretty good performance (but it's a $100K car), but at 200 km/hr, the stopping distance of the M5 increase to 124m (which makes sense since a 200 km/h car has 4X the kinetic energy of a 100 km/h car) Once out of the specialty racing cars, all of the cars "faster stoppers" list took about 27m-30m to stop from 100 km/h so that seems about the best that can be achieved today.

GorgeRonde 8y ago

Since cars and trucks weight vary highly, there is actually a norm that sets how big the breaks should be so that everyone has the same emergency halting distance. This diminishes the chances of a pile-up.