4 ms·

A lot of people don't know how to use engine braking, I guess teaching them that is going to significantly increased your brake pad life on existing vehicles in

A lot of people don't know how to use engine braking, I guess teaching them that is going to significantly increased your brake pad life on existing vehicles in circulation. Remember there are 3 brakes in your car, handbrake, foot brake and engine braking.

airhead969 5y ago
Foot brake and handbrake are effectively the same thing because they operate on shared friction components using mechanical wires instead of hydraulic lines. There maybe a different mechanism but it ultimately uses the same drum or disc. Engine braking (jake braking) by trucks is illegal by statue in many cities and towns because it's very loud. Also, engine braking is riskier in terms of costs (stresses to drivetrain, torque converter, transmission, engine) than brake pads, so people aren't going to do it. Furthermore, they rarely have the skills or transmission to be able to do it conveniently. In addition, if it were more efficient or safer, it would likely be a feature, but I've never seen it in a standard transmission passenger vehicle.
quietbritishjim 5y ago
I'm completely not a car mechanic, so the following is essentially a question phrased as a statement. But I'm a bit skeptical about this idea. I assume you mean the engine break in a manual tranmission car (AKA stick shift in the US). But that relies on your clutch, which is still a friction based mechanism. Admittedly if you're breaking you're probably going to change gear either way, but the amount of friction depends on the difference in revs between the two parts coming into contact, which is presumably going to be larger if you're using it to engine break. So it seems to me that you're reducing wear on your brake pad but just switching that to increase wear on your clutch - with similar effects on air quality.
- Caprinicus 5y ago
  No, it isn’t actually the clutch doing most of the braking, it’s the inherent friction of the engine moving without combustion
- the_pwner224 5y ago
  The clutch is only actuated when changing between gears. Engine braking happens when in gear, and at that point the clutch plates are compressed together and spin as one unit - no dust being generated. Any significant slipping of the clutch would make it burn up very quickly, since cars use dry clutches which cool down by radiating heat into the air. Engine braking happens because engines have very high internal resistance - with motorcycles for example, there's no parking brake, you just leave it in 1st gear and it will not roll. So when you're not on the throttle, the inertia of the wheels/drivetrain will keep the car moving and the engine RPMs from dropping to idle instantly, but over time the engine will drain that inertial energy and slow down the car. Also, engine braking is pretty weak on modern manual cars AFAIK. At least in my Honda Civic it basically doesn't engine brake, compared to my motorcycle. The effect is there but very minor.
  - quietbritishjim 5y ago
    Interesting, thanks!

airhead969 5y ago

Foot brake and handbrake are effectively the same thing because they operate on shared friction components using mechanical wires instead of hydraulic lines. There maybe a different mechanism but it ultimately uses the same drum or disc. Engine braking (jake braking) by trucks is illegal by statue in many cities and towns because it's very loud. Also, engine braking is riskier in terms of costs (stresses to drivetrain, torque converter, transmission, engine) than brake pads, so people aren't going to do it. Furthermore, they rarely have the skills or transmission to be able to do it conveniently. In addition, if it were more efficient or safer, it would likely be a feature, but I've never seen it in a standard transmission passenger vehicle.

quietbritishjim 5y ago

I'm completely not a car mechanic, so the following is essentially a question phrased as a statement. But I'm a bit skeptical about this idea. I assume you mean the engine break in a manual tranmission car (AKA stick shift in the US). But that relies on your clutch, which is still a friction based mechanism. Admittedly if you're breaking you're probably going to change gear either way, but the amount of friction depends on the difference in revs between the two parts coming into contact, which is presumably going to be larger if you're using it to engine break. So it seems to me that you're reducing wear on your brake pad but just switching that to increase wear on your clutch - with similar effects on air quality.

Caprinicus 5y ago
No, it isn’t actually the clutch doing most of the braking, it’s the inherent friction of the engine moving without combustion
the_pwner224 5y ago
The clutch is only actuated when changing between gears. Engine braking happens when in gear, and at that point the clutch plates are compressed together and spin as one unit - no dust being generated. Any significant slipping of the clutch would make it burn up very quickly, since cars use dry clutches which cool down by radiating heat into the air. Engine braking happens because engines have very high internal resistance - with motorcycles for example, there's no parking brake, you just leave it in 1st gear and it will not roll. So when you're not on the throttle, the inertia of the wheels/drivetrain will keep the car moving and the engine RPMs from dropping to idle instantly, but over time the engine will drain that inertial energy and slow down the car. Also, engine braking is pretty weak on modern manual cars AFAIK. At least in my Honda Civic it basically doesn't engine brake, compared to my motorcycle. The effect is there but very minor.
- quietbritishjim 5y ago
  Interesting, thanks!