Rolling

Probably the stupidest question this site has ever heard but I was wondering if sticking a manual car in nuetral would be benificial at all? I was thinking that it would be easier on the engine and wouldnt effect the brakes too much because the hills usually done on arent heavy braking. Also saving a tiny amount of fuel?

Shoot me down out:

[Grunter]

It's not a stupid question if you don't know the answer.

The only drama I could see would be a lack of control if you needed to quickly get on the gas in an emergency situation. The short time it takes to get back in gear may make the difference in making it or not.

Aside from that I wouldn't imagine you'd save much fuel coasting down the hilss anyway.

[pandaman]

I've heard there can be issues if the speed differential between the input and output sides of the 'box is too great, a lunatic trucky I know does it on downhills to get up to insane speeds but keeps the revs up as well. There is also the control issue that has already been mentioned and is my greatest concern. However chucking it in neutral at red lights is a no brainer for me, I always do it, as I have driven a vehicle where the thrust bearing had been rooted from years of extendled idle periods with the clutch in and it was not a pleasant experience.

[efgiar]

why dont you just put the clutch it? drop the revs, and in an emergency you just need to dump the clutch! whenever i have driven a manual thats wat i have done, i also use the clutch to slow down HEAPS quicker in emergency situations eg somone pulling out infont of you

[460cixy]

its called angel gear for a reasion mate. i dont think i have to explane why its called that

[bindi]

I have always used gears to not only accelerate, but to slow me down as well. Going down a hill in gear means you have more control to keep to the speed limit.

There was discussion a while ago on whether this saved you any money... I mean, you would go through brake pads more to stick to the speed limit if you cruise down the hill in neutral because the pull of the engine in gear means you slow down, whereas in neutral it just races away and you have to use the brakes more.

I for one can vouch for this. My rolla needs another carby. I've known this for about a year (running very rich). She backfires occasionally, when I'm going down a hill, if I use say 3rd gear to keep me at the speed limit (which in itself saves you money - nobody likes a speeding fine). So I have adjusted my driving for the time being to compensate for this annoyance... and in this time, have gone through two sets of front brake pads (that's double the normal for my car).

So... do you save money in neutral? Do you use less petrol? I'm not sure, because of the carby issues I can't tell you that (don't have a clear indication).

[MRJUCY]

Coasting to a stop or down hills will use more fuel then using the gears in an EFI car. When the car is in gear & coasting the momentum keeps the engine turning over but in neutral or with the clutch in the engine goes to it's idle program as it needs to power it self to keep it spinning.

When going down hills when I had the manual Pulsator, Id leave it in gear... with the foot to the floor. Twas the only way you could get to the speed limit at the bottom . Just gotta watch out for them damn swift tail winds that send me a few k's over the limit

When slowing down I wouldn't advise downshifting from higher revs to help stop, I would not downshift until the revs got below 1000 rpm. All comes down to is whats cheaper, replacing brake pads or replacing a gearbox or clutch.

[Mike Gayner]

When in gear and the wheels are turning the engine over, an EFI car won't send any fuel into the engine. So staying in gear will actually use less fuel than coasting down a hill.

[FordFan86]

Will this cause any problems with the transmission not being lubricated?

[montyv8]

why would the trans not be lubricated james?

[FordFan86]

I dunno... cauz only the input shaft and output shaft are spinning, and the oils not being pumped around the gears or something rather.. i can't remember what i was told.

[nang3]

Originally Posted by 460cixy

its called angel gear for a reasion mate. i dont think i have to explane why its called that

i was trying to remember hte name for it, thanks 460!!

im guilty of it ocassionally, mainly where the hill is a km or so long with SFA traffic around.. if theres traffic then i never do it..

[Mike Gayner]

Originally Posted by FordFan86

Will this cause any problems with the transmission not being lubricated?

If it's an automatic trans and a ludicrously long hill and you shut the engine down then it could be an issue, but in reality an automatic coasts down hills when in D anyway, and the pump is still working because even an idling engine is enough to sufficiently lubricate an auto. It's not like towing an automatic, where the engine is not running so the pump is not in use.

In a manual, if your foot is on the clutch pedal then the gears won't be moving, so no lubrication worries there. If your foot is off the clutch pedal then the idling engine will be turning the gears, which splash lubricates the box.

[Dauphin]

This reminds me of something else - the way a manual car can decellerate without any brake light warning.

[falcon91]

If the cost of saving a few cents of fuel is required, then Coasting Down Hills in neutral would be extremely low on my to do list. A short but truthful story:
Back in the 70's when there was a bigger panic on oil production than there is now, a mate of mine in a HQ decided that coasting down hills would save him heaps. After coasting down hills for a few weeks, surprise, surprise no noticeable result!
So, he decides to also switch off the engine as well, thereby (In his mind) No idling motor equals fuel saving. Only problem was it was an auto with power assisted brakes.
Conclusion: Could'nt restart the car in time, so no Brakes (Unsure about Power Steering) Smashed through a fence and into a paddock at the bottom of the hill. Cost him a lot more than a few cents to fix.

[Biggoggs]

why dont you just put the clutch it? drop the revs, and in an emergency you just need to dump the clutch! whenever i have driven a manual thats wat i have done, i also use the clutch to slow down HEAPS quicker in emergency situations eg somone pulling out infont of you

So instead of using the brakes to brake, you use steep engine compression, high-rev clutch friction, and driveline shock...? You go through cars pretty quickly, eh :P

When in gear and the wheels are turning the engine over, an EFI car won't send any fuel into the engine. So staying in gear will actually use less fuel than coasting down a hill.

Well it has to send something to the engine, or it'd be like turning your ignition off. I'd be interested to know actually, but I'd assume it was about the same as idle. But then, idle at 1k should use less than idle/compression at 3k...
Either way, I'd assume an engine using enough fuel to keep itself going will use 1/3rd(?) of what it takes to cruise along a flat highway.

[loxxr6]

Coasting to a stop or down hills will use more fuel then using the gears in an EFI car. When the car is in gear & coasting the momentum keeps the engine turning over but in neutral or with the clutch in the engine goes to it's idle program as it needs to power it self to keep it spinning.

I'd heard the same. I've been told you're better leaving the car in gear than putting it in neutral when slowing down. Having said that, half the time I'll pop it in neutral and just let the car slow down by itself.

[MRJUCY]

Originally Posted by ArgonEF

When slowing down I wouldn't advise downshifting from higher revs to help stop, I would not downshift until the revs got below 1000 rpm. All comes down to is whats cheaper, replacing brake pads or replacing a gearbox or clutch.

I always gear down to help slow down the trick is to heel toe to match the revs so there is no real driveline shock, once you get the hang of it it becomes second nature & you can barely feel the shift down.

[rodderz]

Even more dangerous again, we had this ridiculous eccentric teacher at school who actually turned off his valiant station wagon down hills! Too stupid to realise it took more fuel to start than it would running for quite a while

[Peuty]

Originally Posted by 460cixy

its called angel gear for a reasion mate. i dont think i have to explane why its called that

Forgive me for being a little dim, but care to explain?

And yes, I heel toe when downshifting and don;t coast down hills.

[460cixy]

Originally Posted by Peuty

Forgive me for being a little dim, but care to explain?

And yes, I heel toe when downshifting and don;t coast down hills.

lots of truckies used to use angel gear back in the day and im sure theres still some around. and sent lots of truckies off to the angels

[philstoj]

Originally Posted by FordFan86

I dunno... cauz only the input shaft and output shaft are spinning, and the oils not being pumped around the gears or something rather.. i can't remember what i was told.

This is true, the rotating shafts,but not the gears can actually create a vacuum in the box and cause the seals to suck in and you can bugger your box. This is why they tow cars on a tilt tray, or lock the steering, and lift the car from the back(unless its a FWD car)

[gozza]

i put it in neutral at the lights
someone said they don't like shifting untill the revs drop...try double clutchin when downshifting....say ur in 3rd...whack into neutral...kwik squirt of the revs and then into 2nd...if you match the engine speed with the wheel speed u won't even feel the shift...smooth as