driving in neutral to save fuel

darich

Wig wrote: »

I get a clutch changed for £100 labour. Obviously it varies on make/model which only goes to show further how silly your quote was, but my last 4 cars have been £100 or under for clutch.

Doesn't that indicate something about dipping the clutch?????
I don't "dip the clutch" and have been driving for 19years....I've never had to replace a clutch on any car I've owned.

Wig

darich wrote: »

Doesn't that indicate something about dipping the clutch?????
I don't "dip the clutch" and have been driving for 19years....I've never had to replace a clutch on any car I've owned.

Doesn't indicate anything at all, as all of my clutches have been replaced due to friction plate wear never bearing wear. It's more likely to reflect the fact that I drive my cars till they die of old age and I either take on other family members cars or I buy at auction where there can be lots of miles on the clock, and 2 out the last 5 cars were taxis Carlton and Omega which needed clutches every year, and front discs every 6 months (but I digress).

computershack

kaya wrote: »

RUBBISH, with the engine TURNED OFF there is no transmission fluid circulating around the gearbox which will cause the failures you mention in your post, with the engine running the pumps still operate and the fluid still circulates so you can turn the drive wheels safely without causing damage, however if you put the car into neutral whilst moving you are coasting and not driving so you are not in control of the vehicle, very dangerous position to put yourself in

And your mechanical qualifications are?

economiser

I used to this when I first started driving in the 1950's. Anything to save money being an apprentice of £2.15s.8d (£2.53) per week and petrol 5 shillings (25p) a gallon. Living in hilly country there was one route where I could do almost 10 miles with the engine off. Of course cars were simple then, no electronics and it was manual. You do some daft things when you are young!

gsmmad

how about in automatic when you come to a stop and you know you will stop for like 30 seconds, is it better in N or D?

kaya

computershack wrote: »

And your mechanical qualifications are?

qualified electrical and mechanical engineer, crewed on and built dragsters running all over the uk for nearly 20 years, rebuilt many th350's and a good few 700r4's, the section your referring to in the workshop manuals is for when the car breaks down(engine not running) , any auto gearbox specialist will confirm what i am saying is correct, the engine must be running to circulate the fluids, i have towed automatic cars from watford to santa pod(northampton) with bust gearboxes on more than one occasion with no gearbox damage resulting, i also helped build and run europes only functioning hybrid rocket car as well
excuse the quality of the video but you get the idea im sure
http://www.youtube.com/watch?v=RkHlLDVm9GU&feature=channel

Pew_Pew_Pew_Lasers!

gsmmad wrote: »

how about in automatic when you come to a stop and you know you will stop for like 30 seconds, is it better in N or D?

D, with the parking brake on.

shonewillym

As far as I'm concerned, I believe that the most important
aspect of driving a car is safe driving from point A to point B.
It's quite true if you maintain at a particular speed on the road,
you are able to save some fuel for the distance traveled over
the cost in fuel consumption of your car.

Zanzibar

gsmmad wrote: »

how about in automatic when you come to a stop and you know you will stop for like 30 seconds, is it better in N or D?

You leave it in D with the foot brake (not the hand brake) - most modern automatics (mid 90s on) go into Neutral automatically (you will hear the revs drop) when the footbrake is applied at standstill to save fuel and wear. If you leave it on the hand brake it will come back out of neutral.

Also, though it isnt advised, coasting an auto in Neutral isn't the same as being towed (where you have big limitations on how far you can go) as the box is still pumping oil and running it through the oil cooler but only at an idling rate so its not a great idea.

The other issue is that when re-engaging drive after a coast you will clunk back into gear from gearbox idle to road speed which will cause wear prematurely if you did it all the time. You can pre rev back up to approximate revs for the road speed to limit this but its a lot of faf.

How much would it actually affect your gear box? You would get as many outcomes as there are gearbox designs. Some may cope with this others wouldn't and its not worth finding out.

At the end of the day its not worth it for all that and the safety issues mentioned before.

(see.122: http://www.direct.gov.uk/en/TravelAndTransport/Highwaycode/DG_070304)

GSXRCarlos

Hadrian wrote: »

Correct, it was a wartime measure for buses. It was rescinded many moons ago. Also if you turn the engine off (As I once did!) the power steering packs up and it's almost impossible to turn the wheel.

lol i've done that, just don't take the key out so your steering locks :eek: