driving downhill - fuel consumption

Oh yers, because travelling several hundred yards with your foot on the clutch is really the same as a 1 second clutch change, isn't it?

And whats in the middle, dumbass? Oh yeah..THE INPUT SHAFT OF THE GEARBOX.

I'm an apprentice trained C&G qualified mechanic. I expect I know far more about it than you.

I guess you're not a mechanic and have never taken a gearbox off. If you had, you'd realise what bollox you've been spouting as you look at the shiney bits at the end of the fingers which form a circle which is coincidentally the same size as the contact area of the thrust bearing.

Reply to
Conor
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Its best practice. You can still turn the wheel the fastest that way.

Reply to
Conor

I guess you didn't do the gearchange exercise then? I bet you get a lovely burning smell going downhill.

Still there's drivers and screwdrivers...

Reply to
Conor

I bet it isn't too recent though...

I don't think you really need to worry about those either. I've never heard of an engine rebuild being triggered by wear to the crank thrust bearings alone. They're the sort of thing you check or replace as part of a rebuild but, at that time, the cost and effort is trivial.

Cheers,

Colin.

Reply to
Colin Stamp

Quick throttle blip before declutching?

Reply to
Abo

Old triumph (dolomite, spitfire sort) engines used to wear the thrust bearing till it fell out, you then had to take it to bits

Reply to
Mrcheerful

Thus spake johannes ( snipped-for-privacy@size464677743285fitter.com) unto the assembled multitudes:

When I learned to drive a car in 1983 I had been riding motorcycles for 9 years. I was used to the idea of changing up and down through the gears, but my driving instructor specifically told me not to do that in a car, and to remain in top as I braked to come to a halt, declutching only towards the end.

Reply to
A.Clews

grape explained on 19/06/2008 :

That depends upon car and the model.

A manual gearbox with ECU injected engine will consume no fuel if left in gear on a downhill, providing the engine being turned over at above it's tick over speed.

A similar automatic in D will free wheel to some extent, so it will consume fuel to keep the engine ticking over.

Automatic or manual carburretored engine will consume fuel, probably much more than an injected engine with ECU.

Reply to
Harry Bloomfield

No, prolly not. And I did do my test at Wrexham so there was some downhills, but I used the exhaust brake for these and the lorry was un-laden for the test/lessons so braking is only ever really 'pretend' at best.

Julian.

Reply to
Julian

See 'click', above.

Reply to
PCPaul

snipped-for-privacy@DENTURESsussex.ac.uk presented the following explanation :

I'm firmly of the opinion that best practise is to be aware of and be able to use either method, dependent entirely on conditions.

Reply to
Harry Bloomfield

but that would imply removal of the key !!

Reply to
Mrcheerful

Colin Stamp expressed precisely :

A closed throttle, with engine being driven by a hill will cause under oiling if the oiling method is by oil mixed in with petrol.

I once had a bike which metered the oil separately - an engine driven pump, with a stroke which was also adjusted by the throttle opening (may have been vacuum triggered). I think it managed to adjust the mix ratio somewhere between 50:1 and 150:1. The system managed to avoid many of the problems of 2 strokes, was economical on oil, but I did eventually manage to seize it.

Reply to
Harry Bloomfield

PCPaul explained :

If the gear used produces an engine speed just a little above the engines normal tick over speed and if done smoothly, I don't see a problem.

Reply to
Harry Bloomfield

I bow to your mechanical expertise. The last clutch I changed took me a lot longer than 1 second!

Seriously though, It's really amazing how, despite having it spelled out to you, you can continue to miss the fact that there are many more gear changes than prolonged coastings. It's almost as though you're doing it deliberately...

You just can't help digging yourself in deeper can you? It doesn't matter what the input shaft does - there is no force pushing it against the release bearing. No significant wear will happen there unless something is very wrong elsewhere.

Oh no! he's waving his qualifications at me! I'm afraid your C&G only makes your clearly demonstrated lack of understanding even more impressive.

Well, It's patently obvious that you expect very wrong, and you're making it ever more obvious with every post.

Do you *ever* stop to think about the processes you're describing? You should really consider it. You could avoid making a huge tit of yourself on sooo many occasions if only you sat down and thought it through before posting. Of course the ends of the fingers get polished - Every time the clutch pedal moves, the bearing has to push the fingers in causing them to slide in towards the middle of the bearing. The movement only happens whilst the clutch pedal is actually moving though.

Cheers,

Colin.

Reply to
Colin Stamp

Many ignition barrels require you return the key to the 0 position before being able to move it back to the "run" position. The only problem with this is that it engages the steering lock.

Reply to
Conor

Oh, and don't forget to pull the handbrake at each stop, LOL. you could always see from the shoulder movement on the driver in front when he pulled the handbrake.

Reply to
johannes

It certainly depends on how you were brought up. Yes, you see TV clips of police drivers shuffling very fast during pursuits, but it still looks ridiculous IMO. I doubt if rallye drivers are doing this.

Reply to
johannes

OTOH you shouldn't need much steering movement in most driving - maybe in town, but on the open road you rarely need to move the wheel more than 30 degrees in either direction. And knowing which way is straight ahead (ie, by keeping your hands in a fixed position) is required if your car oversteers.

Reply to
Doki

Rally drivers cross arms.

Reply to
Harry Bloomfield

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