Do you engine compression brake?

[snymat68]

Originally Posted by 130R

When I REALLY have to slow, I have an anchor I throw out...

Does it say Prius on the side?

[offduty]

Saves on brake pads and brake dust also. Love the de-cell sound at higher RPMs with open exhaust

[Bhobbs]

I downshift all the time but never skip a gear. I go gear by gear until I stop.

[thahemp]

Originally Posted by ORANGE U NV

There is gear friction, either accelerating or down shifting (gear braking). This friction is reduced by all the oil in the drivetrain componets.... but there is friction (wear) transmitting all the engine power to the tires or from the tires to the drivetrain when gear braking.

When placing a car in neutral, the only thing slowing you down is the tire friction, wind resistance and gravity. When you gear down and feel that braking force, thats the friction in your drivetrain that is slowing you down. Down shifting can be just as stressful (wear & tear) as hard accelerations on your drivetrain. I'm not saying do or don't.... but there's no "free" braking. You either wear (friction) the brake components or the driveline componets.

Gravity doesn't slow you down. It's actually trying to accelerate you towards the core of the earth. It's not drivetrain friction slowing you down either. It's the engine.

[MADBADGER]

Originally Posted by thahemp

Gravity doesn't slow you down. It's actually trying to accelerate you towards the core of the earth. It's not drivetrain friction slowing you down either. It's the engine.

The tires rolling resistance will slow you down. This force is caused by the weight on the tire. weight is caused by acceleration (or gravity) on a mass.

a vehicle in low gravity would coast farther than a vehicle in high gravity. given that gravity is the only variable.

So gravity does slow you down, in a sense

[jd10013]

what am I missing here? if I want to slow down, I use my brakes. change them about every 60k, and I'm fine with that. why would you want to put any extra wear on your drivetrain to get an extra 5k miles on a set of brake pads

[snymat68]

Originally Posted by jd10013

what am I missing here? if I want to slow down, I use my brakes. change them about every 60k, and I'm fine with that. why would you want to put any extra wear on your drivetrain to get an extra 5k miles on a set of brake pads

So we can have discussions about gravity and friction on the forum!

[jninan2k2]

I got the Jbrake option on my camaro...works much better

[Caspers2SSRS]

Originally Posted by thahemp

Gravity doesn't slow you down. It's actually trying to accelerate you towards the core of the earth. It's not drivetrain friction slowing you down either. It's the engine.

In all fairness no single answer defines the known theories of gravity or in this case the phenomenon known as gravitational pull. In the instance that an automobile were traveling on an uphill incline and your were to downshift, gravity would lend a hand in slowing the mass of your automobile. Applying the same mechanic's while traveling downhill would require a greater amount of resistance whether that would be shifting to a lower gear, applying more pressure on the brake pedal, or a combination of both..........the variable's are endless until you've actually stopped. If you've stopped on perfectly level ground gravity itself keeps you there. Its isn't the brakes or transmission. The opposite scenario occurs on inclines as gravity pulls the mass of your automobile downhill. Being the automobile's mass is comprised of the total mass of all of its components it can be theorized that each component plays a role in slowing the automobile down....including there resistance to forward motion. Toss into the endless equation, wind, the geometry of the suspension components, tire's, wheels, and aerodynamics's, etc. In simpliar terms, the friction created decelerating the mass of the automobile. The engine is just one of the components of the power train.......as yes it can be braked.

[ThingFish]

Engine brake all the time.

[thahemp]

Originally Posted by MADBADGER

The tires rolling resistance will slow you down. This force is caused by the weight on the tire. weight is caused by acceleration (or gravity) on a mass.

a vehicle in low gravity would coast farther than a vehicle in high gravity. given that gravity is the only variable.

So gravity does slow you down, in a sense

Gravity is definitely where the friction comes from, but the post i was responding to listed friction AND gravity. Also, the effects of friction in an engine braking scenario are negligable compared to the engine.

Originally Posted by Caspers2SSRS

If you've stopped on perfectly level ground gravity itself keeps you there. Its isn't the brakes or transmission.

Technically, the ground keeps you there. Move the ground out of the way and you'd be off and accelerating again.

[13lstuner]

Gosh the semantics debated on this forum blows my mind. My major will be physics in two years when I graduate, but truthfully all of this seems like everyone trying to prove the last man wrong. The original purpose of this thread was making sure that downshifting would not exponentially increase the mechanical wear on his tranny, or whatever you would like to say. Now it is just useless bantering and everyone trying to prove the last man wrong. The OP doesn't need to understand the forces acting upon his car. Especially completely irrelevant information like if the ground wasn't there, and neither does anyone else. So just answer the question to the best of your ability, or if you have no clue just move on. I will learn the "string theory" and quantum mechanics another time.(I know that is not what you all were explaining please do not start flaming me for joking)

[offduty]

Yea and what he said

[KaBoom1701]

Originally Posted by 13lstuner

Gosh the semantics debated on this forum blows my mind. My major will be physics in two years when I graduate, but truthfully all of this seems like everyone trying to prove the last man wrong. The original purpose of this thread was making sure that downshifting would not exponentially increase the mechanical wear on his tranny, or whatever you would like to say. Now it is just useless bantering and everyone trying to prove the last man wrong. The OP doesn't need to understand the forces acting upon his car. Especially completely irrelevant information like if the ground wasn't there, and neither does anyone else. So just answer the question to the best of your ability, or if you have no clue just move on. I will learn the "string theory" and quantum mechanics another time.(I know that is not what you all were explaining please do not start flaming me for joking)