hey guys.

so i was on the highway, down a steep hill,
and my dad was changing gears to a lower gear (2nd, he drives an automatic).

now is that bad for the transmission?

i've heard it is good for trucks and heavy vehicles because it reduces wear and tear or parts like the tyres, brake disks, etc.

now is it good for passenger cars?

my dad's is a toyota tarago.

i think it's a 4 cylinder 2.4l engine.

hey guys.

so i was on the highway, down a steep hill,
and my dad was changing gears to a lower gear (2nd, he drives an automatic).

now is that bad for the transmission?

i've heard it is good for trucks and heavy vehicles because it reduces wear and tear or parts like the tyres, brake disks, etc.

now is it good for passenger cars?

my dad's is a toyota tarago.

i think it's a 4 cylinder 2.4l engine.

It's not gonna make a lick of difference to the tyres.

It won't significantly hurt the engine or transmission, if you keep within reasonable bounds.

It will perhaps save the brakes some wear (but they are a wear item anyway so who cares).

But normally the reason it is done is down very long or steep hills, to avoid the brakes overheating, especially with drum brakes. That really probably isn't an issue with the average passenger car.

except on clyde mountain, on the south coast.

people always stack it there

Unless you're popping it into 2nd at 120 mph, it's not going to hurt.

My jeep is a manual, and it is very hilly where i live. I use engine braking a lot, not to reduce wear, just to make it easier. if i keep it in third instead of going into fourth, i can roll down a hill at a very reasonable speed without having to touch my brakes.

Look in your owner's manual, it'll probably say something about it.

My 96 toyota's manual says that you can shift the selector from D to 2 and the transmission won't downshift to 2nd until the truck has slowed to a certain speed (60 mph), the same thing goes for shifting from 2to L.
I can't remember what it said for manual transmissions but I figure they would probably list the maximum speeds for each gear.

I was taught to do it to save the brakes from overheating and glazing.

It's done when off-road going down a steep slope to prevent the wheels locking up and sliding you sideways. Even ABS normally isn't enough for fine control.

Otherwise, I'm pretty sure that it saves a lot of wear (and possible overheating as leady said) on long hills.

If you are driving a fuel injected car engine braking saves fuel. That's because the injectors can turn off since the engine is being turned over by the wheels. If your car uses carburetters the idle jets still draw fuel during engine braking.

If you are driving a fuel injected car engine braking saves fuel. That's because the injectors can turn off since the engine is being turned over by the wheels. If your car uses carburetters the idle jets still draw fuel during engine braking.

Maybe in a few select newer vehicles...

Maybe in a few select newer vehicles...
True, this. Not all fuel injected cars can turn their injectors off, certainly not older ones with the early Bosch systems.

My VW Polo had a Bosch system which I found out wasn't capable of turning them completely off, just running at a lower rate than idle.

you've made a few threads about your dads driving habits/car?

are you concerned your dad is damaging his car, or are you just interested in what he is doing?

good to see you are paying attention to an experienced driver either way, you might learn something.

It's generally a good idea to use low gear on steep hills, it saves your brakes and you have more control over the vehicle.

but you should remember that brake pads are worth about $50 where as your gearbox is worth a few thousand. I drive manual so it's a little bit different but even in an auto it's good for retaining control, I don't like to brake all the way down through corners and bends.

what highway where you on? chances are me or someone on this board from the south coast will have driven on it at some point

interested in what he's doing.
he;s a good driver, though he's getting old. (61).


i'm on my L's, and i havn't driven yet (dad wants me to go to a instructor for the first 10 hours)
it was near the blue mountains. the highway from sydney to blue mountains, then to bathurst

that'd be the great western highway.

you won't go through low range gears and steep hills at first with an instructor anyway.

are you learning manual or automatic.

You should try to get your licence as soon as possible. The legislators are thinking of increasing the age you can get your licence to 18 :rolleyes: That's the minimum age in Victoria.

I take it you have to do 120 hours. I did. It's hard for some parents to commit that many hours. Try to convince your parents that you have learnt quickly. That way whenever you and your parents have to go for a drive somewhere you are the one driving. Every time you have to go somewhere in a car ask if you can drive.

Back on what I was saying about fuel injected cars - I have noticed my fathers car which has a fuel consumption gauge never goes down to zero. It does go below what it consumes at idle if engine braking is used. Why do the injectors not go to 0% duty cycle :confused: It's not like fuel is needed.

I have noticed my fathers car which has a fuel consumption gauge never goes down to zero. It does go below what it consumes at idle if engine braking is used. Why do the injectors not go to 0% duty cycle :confused: It's not like fuel is needed.What fraction of the idle fuel consumption does it go down to?

This is just a guess but maybe it's b/c your engine/computer doesn't necessarily 'know' that no fuel is needed, as in the computers haven't been designed to sense when engine braking is occurring...?

Or, maybe they have been designed to sense engine braking and that little bit of fuel is for cooling purposes?

the injector pulse will never drop to zero because the engineers decided to make sure the engine keeps running.

say you were coasting down a hill and the injector pulse drops to zero. all of a sudden a retarded child runs into the road. now the earth first thing to do would be remove this unnecessary life form from existence. alas there are laws against that. anyhow, with your engine essentially not running you slam the brakes and the car comes to a halt. the wheels are no longer turning the engine, the engine is dead. now a large truck is hauling even larger construction equipment behind you. he has already overheated his brakes. (too much trucker speed has dulled his senses) the tard is out of your way, but you cant move quickly enough. the drooling dimwit lives, but you are a smear on the pavement. all because some pencil necked geek was forced to find a way to squeeze .01% more gas mileage out of a vehicle,...

well this is at least my assumption why this is done.

the injector pulse will never drop to zero because the engineers decided to make sure the engine keeps running.

say you were coasting down a hill and the injector pulse drops to zero. all of a sudden a retarded child runs into the road. now the earth first thing to do would be remove this unnecessary life form from existence. alas there are laws against that. anyhow, with your engine essentially not running you slam the brakes and the car comes to a halt. the wheels are no longer turning the engine, the engine is dead. now a large truck is hauling even larger construction equipment behind you. he has already overheated his brakes. (too much trucker speed has dulled his senses) the tard is out of your way, but you cant move quickly enough. the drooling dimwit lives, but you are a smear on the pavement. all because some pencil necked geek was forced to find a way to squeeze .01% more gas mileage out of a vehicle,...

well this is at least my assumption why this is done.

When the engine drops below a certain speed or you place your foot on the throttle the injectors should open again. I cannot see any reason the injectors stay open during engine braking.