Power, Torque and their relation to grip

[eltax91]

Hi all

I'm having a bit of an internal mind wrangle, so I'm throwing out a wintery-themed question to the PH masses.

Yesterday, I was visiting my mother in laws house. She has a moderately steep driveway, which she had cleared of snow after the first dumping. As the first drops of yesterdays flurry started to fall, she posed me the question: "Am I best leaving the car pointing down hill, or turning it around whilst I know I can get off the drive, as I need to try to attempt to get to work on Monday".

The car, for the record is a 1.5 Almera, so FWD. Now, I know that in order to give myself a better chance of getting going on the slippy stuff, I need to use 2nd gear. I think this is because 2nd gear give me less torque than first, right? If so, then surely reverse is very low speed and very high torque in terms of gearing? By that logic, reversing on the drive and using 2nd gear to try and get off it would be the best option? So, PH's, do your worst, ridicule me.

P.S. Can the "should have bought winter tyres" brigade stay away from this one please.

[samoht]

I assume that the drive slopes downwards from the road.

You're correct that reverse is higher torque.

However, reversing uphill has the benefit that the weight transfer will be onto the driven wheels. I guess this would outweigh the benefits of lower torque. So I would leave it pointing down.

Actually, I would have got the car out of the drive and left it parked on the road or pavement overnight if I thought there was a question of not being able to get it out in the morning, but I don't know if that's possible for you.

[ging84]

should have got a shovel and cleared the drive and gritted it

[StottyZr]

Reversing uphill in a FWD is always the best idea as the weight is on the driven wheels.

No idea what you're talking about second gear having more torque than first though. The gear will produce less torque at the wheels, which reduces wheelspin I believe.

[Mr2Mike]

eltax91 said:

I think this is because 2nd gear give me less torque than first, right?

StottyZr said:

No idea what you're talking about second gear having more torque than first though.

[e635815]

On a diesel car, you'd better engage first gear and declutch without accelerating.
The idle speed is good enough to get away from most of the situations. Unless your drive is too steep.
On a petrol car, I don't know, since both of them are hibernating in the garage.

[ging84]

doogz said:

Unless he's edited it, he says it'll produce less torque, not more.

And I don't get this whole pulling away in second malarkey. Never had a problem pulling away in first, and even just idle in second gear is going to be somewhere near twice the wheel speed of first gear, which is what is going to spin the wheels.

this would be true if there was no such thing as a clutch

[eltax91]

ging84 said:

should have got a shovel and cleared the drive and gritted it

In my OP. I think I mentioned she had cleared it? It's just what to do when you wake up in the morning and find the pretty white stuff has landed on your cleared/ gritted drive. Clear it away and thus take the grit with it? Or, attempt to drive?

[StottyZr]

Mr2Mike said:

eltax91 said:

I think this is because 2nd gear give me more torque than first, right?

StottyZr said:

No idea what you're talking about second gear having more torque than first though.

No idea what you're talking about either