Questions about an automatic gearbox

[TVR IS KING]

So I'm learning to drive.
My mothers car is an automatic family wagon thing, and my drive home often involves a climb up a windy steep hillside road. My mother has been telling me that I should take it out of 'drive' mode, and put the car in gear 3 while going up the hill, to relieve stress from the engine.
I happen to believe she (and her boyfriend who told her) don't know what they're talking about.
So does this actually help at all?
Is it actually the engine that's getting stressed? I can see the gearbox, or parts of it getting stressed from shifting gears around, but the engine? Is the automatic likely to stress the engine by leaving it in the wrong gear?

Also, today I followed her advice (she was sitting next to me :\), and I left it in third all the way up the road. Is third gear acceptable, considering I sat in it from around 15km/h up to about 60? If third is fine for 15k/mh, where to second and first come in?

I also managed to cut off some people and run a red light. I don't do enough city driving, there is less to worry about in the country >.<

[jediali]

The autobox is linked to the engine via a torque converter, this ensures engines strain during shifts is minimised. As i see it there is no difference in engine stress between "drive" and "3", as long as you are using suitable engine speed for the gradient, if the engine gets bogged down in "3" or your revving the crap out of it this will do more damage.

[TVR IS KING]

Yeah I figured that was true, that if you can hear the engine revving high, or you're hardly moving and mashing the accelerator...you're in the wrong gear

And I figured that all drive does is select the correct gear, and if that gear's third, then the box can choose it just as well as I can.
What's the correct rev range to change gears in a car like this? V6 if that helps...I know in drags on games like NFS (I know, NFS) you change at like 7000 revs, but our cars auto changes at around 3000...

[jediali]

Most mass production petrol engines produce good torque from around 1700-3500rpm, try and stay in that rev band. generally the gearbox will decide, but say in a manual you really should avoid under/over-revving before the accelerator becomes unresponsive or you see your valves bouncing through the bonnet, thats what economical driving is all about, minimum revs without stressing the engine. I often set myself the challenge of staying below 2000rpm, it forces me to drive smoother and think further ahead. This even means going down 30mph zone hills in 5th at 1300rpm because its fine.

[TVR IS KING]

I see. Thank you very much.
So the final verdict is that choosing my own gear isn't any healthier for the car than letting it choose itself, in this situation?

[jediali]

Your choice is better if you have control and a bad automatic gearbox, otherwise leave it alone.

[ruim20]

I see. Thank you very much.
So the final verdict is that choosing my own gear isn't any healthier for the car than letting it choose itself, in this situation?

Exactly, it's AUTO... therefore it does all the thinking by itself

[pimento]

3 just means that third is the highest gear it will go to, at 15km/h it's probably using second or first anyway. Also it's more important going downhill, as it'll keep the revs up and allow the limited use of engine braking, thereby enhancing control.

[SlickHolden]

So I'm learning to drive.
My mothers car is an automatic family wagon thing, and my drive home often involves a climb up a windy steep hillside road. My mother has been telling me that I should take it out of 'drive' mode, and put the car in gear 3 while going up the hill, to relieve stress from the engine.
I happen to believe she (and her boyfriend who told her) don't know what they're talking about.
So does this actually help at all?
Is it actually the engine that's getting stressed? I can see the gearbox, or parts of it getting stressed from shifting gears around, but the engine? Is the automatic likely to stress the engine by leaving it in the wrong gear?

Also, today I followed her advice (she was sitting next to me :\), and I left it in third all the way up the road. Is third gear acceptable, considering I sat in it from around 15km/h up to about 60? If third is fine for 15k/mh, where to second and first come in?

I also managed to cut off some people and run a red light. I don't do enough city driving, there is less to worry about in the country >.<

What's the car man??

I have Auto and if i climb hills no matter what speed i can drop it with acceleration to pick up easier.. But it my model car i can if i choice to drop it to the second D which makes it a 3 speed, I sometimes in big traffic on the freeway use this to help slow so i don't ride the brakes,, But never up a hill.. Even in cruise the car will hold that speed even going up a hill it will even drop a gear or 2 to keep the selected speed.

[Ferrer]

Most mass production petrol engines produce good torque from around 1700-3500rpm, try and stay in that rev band. generally the gearbox will decide, but say in a manual you really should avoid under/over-revving before the accelerator becomes unresponsive or you see your valves bouncing through the bonnet, thats what economical driving is all about, minimum revs without stressing the engine. I often set myself the challenge of staying below 2000rpm, it forces me to drive smoother and think further ahead. This even means going down 30mph zone hills in 5th at 1300rpm because its fine.

No, you're wrong. Thrashing the hell out of an engine is fun.

Altough very often I also change at about 1500rpm. Supercharged power and torque ftw.

[fisetdavid26]

No, you're wrong. Thrashing the hell out of an engine is fun.

I read on the intrawebz it's not recommended to rev the engine above 3,000 rpm in my Camry... if I'm not getting enough money for parts when I'll be changing it, multiple 0-60 tests ftw!

[SlickHolden]

Naughty boy you can't say torque

[taz_rocks_miami]

No, you're wrong. Thrashing the hell out of an engine is fun.

Altough very often I also change at about 1500rpm. Supercharged power and torque ftw.

You shift at 1,500 RPMs? How do you get anyware? I shift at 3,000 on the street and at around 5,000 on the highway.

[Ferrer]

You shift at 1,500 RPMs? How do you get anyware? I shift at 3,000 on the street and at around 5,000 on the highway.

Not always, but when I drive relaxedly I shift between 1500-2000rpm. The Mini can pull easily from 1000rpm even in sixth, which helps. When I'm in the mood I shift at 6000rpm...

[jediali]

No, you're wrong. Thrashing the hell out of an engine is fun.

Altough very often I also change at about 1500rpm. Supercharged power and torque ftw.

ok dokay, i thought he wanted a quick general description, not a second thesis on bmep vs engine rpm. If he wants to drive his mother to the shops he wont be doing 6751.43rpm. Maybe he should fit a tiny scandium turbine turbochargers to each exhaust outlet, use heteregenous mixture control and have a bore:stroke ratio of 1:10 so he can rev it at 10rpm without any problems.