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Is it bad to leave car in gear on a hill?

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Old Jun 2, 2006 | 01:00 PM
  #16  
Noogles's Avatar
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Originally Posted by AznX TL
5th gear can't picking up from a stop doesnt have to do with the car when the engine is off.
Are you serious?!?

It is easier for a car to roll in furst gear because of the lower gear ration(the tires will "X" number of times for every rotation of the motor.

If it is in 4th (closest 1:1) or fifth you are having to fight a full compression stroke before the wheels will even turn.
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Old Jun 2, 2006 | 01:17 PM
  #17  
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Originally Posted by Noogles
Are you serious?!?

It is easier for a car to roll in furst gear because of the lower gear ration(the tires will "X" number of times for every rotation of the motor.

If it is in 4th (closest 1:1) or fifth you are having to fight a full compression stroke before the wheels will even turn.
Yes, AznX TL is right. You have it backwards.
1st gear is a low gear ratio when driving forward (the crankshaft spins multiple times for each rotation of the wheels).

You generally can't start moving in 5th gear (unless you're testing a Corvette Z06 on Top Gear) because the overall gear ratio is so low that the engine torque is not being multiplied by enough to get the car moving.
But when the engine is off and you're parked on a hill in 1st gear, gravity is trying to backdrive the drivetrain from the wheels, and the high gear ratio (when back-driven) multiplies the engine resistance (multiple back-driven crankshaft turns per wheel rotation).

Last edited by ru4real; Jun 2, 2006 at 01:22 PM.
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Old Jun 2, 2006 | 01:22 PM
  #18  
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A simple test to determine who is right would be to go out in a parking lot, put the car into gear while its off(w/o the e-brake of course) and give it a shove in both 1st and 5th and see which one moves.
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Old Jun 2, 2006 | 01:24 PM
  #19  
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Originally Posted by ru4real
Yes, AznX TL is right. You have it backwards.
1st gear is a low gear ratio when driving forward (the crankshaft spins multiple times for each rotation of the wheels).

You generally can't start moving in 5th gear (unless you're testing a Corvette Z06 on Top Gear) because the overall gear ratio is so low that the engine torque is not being multiplied by enough to get the car moving.
But when the engine is off and you're parked on a hill in 1st gear, gravity is trying to backdrive the drivetrain from the wheels, and the high gear ratio (when back-driven) multiplies the engine resistance (multiple back-driven crankshaft turns per wheel rotation).

Bingo!!!
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Old Jun 2, 2006 | 08:10 PM
  #20  
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From: hershey,pa
ok wheres my cookie at?
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Old Jun 3, 2006 | 07:09 AM
  #21  
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When you leave your car in gear on a hill, the tranny takes the strain of holding the car in that position. You can simply leave your wheels turned the appropriate way, and put on your emergency brake, sparing your tranny. Just keep your emergency brake in good condition and adjustment. Brakes are cheaper and easier to replace than trannys that have been used for brakes.
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Old Jun 3, 2006 | 07:18 AM
  #22  
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owners manual even says when parked facing downhill, put the car in 1st gear, and when facing uphill, put the car in reverse

edit: you need the e-brake
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Old Jun 3, 2006 | 12:47 PM
  #23  
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i read that also which seems to be very odd.
i was alwayz taught the opposite.


Originally Posted by PKEVO8
owners manual even says when parked facing downhill, put the car in 1st gear, and when facing uphill, put the car in reverse

edit: you need the e-brake
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Old Jun 3, 2006 | 12:58 PM
  #24  
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Originally Posted by KOEvo
I am pretty sure 5th has more resistance. If you think about it getting 5th gear to spin from a stop normally would be near impossible, and horrible for your clutch. 1st just spins up like nothing. It's basic physics.

The problem is, you are thinking about it too much.

1st for uphill, reverse for downhill. 1st for downhill is not necessarily a bad thing either. Regardless of what kind of strain it puts on the transmission, you owe it to yourself and others to put the car in a safe position once you've left it.


'Nuff said!


Cabo
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Old Jun 3, 2006 | 06:46 PM
  #25  
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From: hershey,pa
Originally Posted by [TYPE]SS
i read that also which seems to be very odd.
i was alwayz taught the opposite.
you were told reverse for uphill and 1st gear for downhill.........thats just asking for it to roll down the hill
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Old Jun 3, 2006 | 08:45 PM
  #26  
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^^ he's refering to the owner's manual
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