Mobile phones legislation comes into force today...

[cjolley]

Originally posted by Gurm
I understand that the law exists, but it's stupid.

You produce more tree-killing emissions when starting than in 10 minutes of idling.

- Gurm

That sounds right, but I wonder if it's realy true given the use of catalytic converters.
I have no idea....
Any one have data?
chuck

[Gurm]

Catalytic converters only do so much.

When you start the car, it runs rich for a period of time, anywhere from 30 seconds to 5 minutes depending on engine temperature.

That "running rich" can put between 5 and 10 times more emissions into the atmosphere.

TRUST me here - my Bimmer wasn't warming up properly (thermostat problem), and I failed emissions quite spectacularly as a result. It was always running like it does when starting.

- Gurm

[borat]

dont really know, but its an amazing concept. they did a study in paris and cars were stationary for 30% of their city journeys. abviously its impracticall to turn the key on and off but manufacturers are deeveloping fly wheels and other technologies which cut the engine when you pop it into neutral when stationary then it flicks the engine over when you engage the clutch again. i'd buy it if it saved me a bit of petrol and was only a few hunded £'s. Personally id like to see less reasons to stop the car though. where i live they are in the process of putting in a traffic light crossing and reducing the road from 2 to 1 lanes each way, 6 feet from a footbridge, to allow the local comprehensive kids who are too lazy to use the bridge to cross the road. Fact of the matter is the kids dont use the bridge because they prefer to walk up the pavement pushing over the bins and then making gestures to the cars as they cross at the end of the road.

[jonnylane]

Originally posted by cjolley
That sounds right, but I wonder if it's realy true given the use of catalytic converters.
I have no idea....
Any one have data?
chuck

Most of the stuff I've found says that starting is indeed worse for emissions than just ticking over (up to a certain time, of course).

I found one site that said the biggest culprit is air conditioning when stuck in traaffic jams. It was a pretty poor argument, though.

A guy I know (this is back in pre-uni poverty days) used to turn his engine off when going down hills to save money. Not recommended, since the brakes didn't work. I remember he also used to shift his gears 1st, 2nd, 5th when moving from stationary. Minimal acceleration but lowers the revs.

I wonder if he did actually save any money..

[TransformX]

I believe that every penny saved on the road was spent in the garage.

[Wulfman]

Originally posted by Gurm
When you start the car, it runs rich for a period of time, anywhere from 30 seconds to 5 minutes depending on engine temperature.

That "running rich" can put between 5 and 10 times more emissions into the atmosphere.

TRUST me here - my Bimmer wasn't warming up properly (thermostat problem), and I failed emissions quite spectacularly as a result. It was always running like it does when starting.

- Gurm

that's certainly true for a "cold" start, but the motor should be already warm when you stop at a traffic light. I don't think it cools down enough during the few minutes to justify a higher fuel-flow.

mfg
wulfman

[Gurm]

It does. And it doesn't matter if it stays "warm", you still get the rich running - the engine computer makes sure of that.



Plus even a couple minutes off will cause the thermostat to reset.

- Gurm

[az]

Well, VW developed some kind of "eco-Golf" a few years ago that would shut the motor off everytime you stopped. I think they'd have put some research into this, wouldn't they?

AZ

[The PIT]

I'm just wondering how long it would take the average dumb road user to remember they had to turn the engine on again. It takes several minutes for them to find the handbrake let alone the ignition key. You'd get about one car through the traffic lights if you had to turn the engine off.

[agallag]

That's gotta be hard on the battery and starter motor too, don't ya think?

[THE_Editor]

the engine computer makes sure of that.

There's a lot to be said for a 50pence set of points !!

( If Sir can afford the car .. Then Sir can afford the £650 for a new module !!)

[DukeP]

VW and AUDI has economical cars that automatically stops the enginer when the car is stationary.
The technology involved supposedly only work with diesel motors (I guess its something about keeping the compression?).
THeir little VW GOLF runs about 100km on 3 liters of diesel (I have tested this, yes, even on higways doing 140ish km/h).

When the engine stops, it starts again in less than 3 seconds - it doesnt feel like a slowdown at all.

~~DUkeP~~

EDIT: Also in Toyotas, heres the link.

[Wombat]

The gasoline hybrids here in the states also stop/start combustion nearly instantly.

[az]

Jaguar has a prototype that stores compressed air in a tank when you brake, and uses this air to propel you forward when you start again. The motor only starts after a second or so, and I think the ignition is provided by the turning wheels. This saves quite a lot of energy, because it costs much more energy to get a stationary object moving than to keep an already moving car moving.

AZ

[Dr Mordrid]

This was tried with flywheels too, but keeping those together at the speeds required to store enough energy was a problem. So was their weight and physical size.

Hybrids are actually the best idea; enough so that the US military is getting hybrid versions of personnel carriers, attack vehicles and even the HumVee. Seems they're so quite they can sneak up on an enemy position almost unheard 'til it's too late.

The US Army is also getting versions of Chryslers 2004 hybrid powered Dodge RAM pickup truck.

Yup....a hybrid powered Dodge RAM pickup

Dr. Mordrid