Discussion in 'Motorhome Chat' started by ShiftZZ, Nov 12, 2011.
Is it legal or not?
A friend said that it was illegal as you were not in control of the van.
Hi ShiftZZ, the authorities outlawed the built-in Freewheel as found on early Saab and Rover 95 back in mid 60's and as I understand it if by free-wheel you mean what I call coasting (out of gear-low engine revs, downhill sort of thing) that is illegal as you are not in full control of the vehicle.
Someone I'm sure will put me right if I'm wrong which of course is unlikely as My Missus keeps [STRIKE]Yelling[/STRIKE] telling me.
Popeye that is my understanding too! It can have frightening consequences if it is done. Many eyars ago I did it going downhill for about a mile and when I reached the bottom flung it back in gear.....................
what I hadn't realised was that whilst I was freewheeling the fuel pump was still pumping fuel so when I engaed the clutch fuel vapour filled the exhaust and ignited with a deafening roar and flames shot out of the back.
The car behind didn't travel so close after that
It sound as if your engine died while coasting or you switched the ignition off. Either way when the engine restarts that is exactly what you will experience especially if you have the slightest air leak in the exhaust.
Many years ago if we had a car in for exhaust replacement (blowing) we would rev the nuts out of the engine up to around 6000 rpm, immediately switch the ignition off and wait the short time for the engine to slow down, all this time unburnt fuel would be travelling into the exhaust.
Then at the last second before it stopped completely we would switch the ignition back on and all the unburnt fuel in the exhaust would ignite and sometimes explode.
Often the resulting 'Backfire' would remove the exhaust from the car so shortening the labour time associated with the repair.
Made one hell of a bang in an enclosed space, perfect for juvenile apprentices........Griff
When I was with the MP's in the late sixties, I was a courier on a motorbike called Matchless. I used to announce my arrivel by doing just that. One day the lieutenant was outside and was scared out of his green underpants by the explosion, so it got outlawed. Shame though, the cook started dinner at our loud arrivals! :shout:Hans.
Another thing is that if you're freewheeling to save fuel, apparently most new vehicles save more if you simply take your foot completely off the accelerator.
More info here: http://www.mpgtips.co.uk/faq/if-i-freewheelcoast-downhill-in-neutral-will-i-save-fuel/
As far as I know it's only legal if your name is Bob Dylan :BigGrin:
Nice one! :Laughing:
It's certainly only cool if you're Bob Dylan :Cool:
the question should read 'who would know if you were free-wheeling ?'
an auto box has very little engine braking compared to a manual box, so it's effectively free wheeling down most hills
Aren't you 'freewheeling' when you depress the clutch? (albeit only momentarily)
So it can't be illegal can it? :Wink:
Freewheeling - Whilst the engine is at tick over, there is not enough vacume being created to operate the brakes effectively at speed.....
for those that do not have mechanically operated brakes.
there should be more vacuum in the inlet manifold, which is where brake servo vacuum is take from, when the throttle butterfly is closed (tick-over).
the pistons are still trying to pull the correct amount of air through too small a gap causing a higher manifold vacuum.
brakes are tested at tick-over for the MOT and meet the minimum efficiency at least.
this is why a diesel engine has a separate vacuum pump.....no throttle butterfly in a diesel
"Who would know" is irrelevant, John.
Not in full control is not in full control, that's it.
A little tenuous, Bryan!
As far as I know it sounds like s**t if you're Bob Dylan........
Once got nicked coming down Beattock in an Atki Borderer with 2 10 ton coils of steel on. The Gardner governor came in at 50 MPH so we used to knock it out of cog coming down big hills on the motorway,which was much quieter then.
The traffic cop said I was doing 78 but booked me for doing 63 which carried a smaller fine. I must add I was young and foolish in those days. Not so now...or so I would like to think so.
I know 'coasting' defo used to be illegal but I have this thought somehwere at the back of my brain cell that they lifted that, yonks ago, when we had that fuel shortage ..... seem to recall saying this to husband #1 in a traffic jam going downhill one day at that time, when he was coasting and that was his answer.
No idea if he made it up to shut me up or what? I mean he wasn't prone to lying, we hadn't fallen out, I wasn't otherwise giving him an earful or owt, it was just a comment eg Oooh you bad boy, cos you is coasting! whilst we were on the way home from work. If they hadn't said that, he could just as easily said I know but I'm doing it to save petrol - and I'd still have been perfectly happy.....
I only freewheel when i run out off titty:Rofl1::Rofl1:
For those with good memories - Ford Pop - vacuum operated windscreen wipers -went slower the faster the engine was revving. (Reduced vacuum at higher engine revs):thumb:
I'm really looking forward to meeting you Yosser, if for no other reason than to explain exactly what the hell you are talking about on this here thread..................straight over my head........is it me?....Griff - Swift - Popeye, take your pick...........
From the Highway Code :
Control of the vehicle (117-126)
This term describes a vehicle travelling in neutral or with the clutch pressed down. It can reduce driver control because
* engine braking is eliminated
* vehicle speed downhill will increase quickly
* increased use of the footbrake can reduce its effectiveness
* steering response will be affected, particularly on bends and corners
* it may be more difficult to select the appropriate gear when needed.
so it is not illegal, but if you were involved in an accident whilst free wheeling you could be guilty of not being in full control of the vehicle ..
Personally I think it is a stupid thing to do .. saves no fuel and puts you and others at risk ..