OT: cars at traffic lights

My car (and I assume others) have several conditions that need to be met before stop-start operates, when it does, it stops the engine with a known cylinder at TDC ready to inject fuel and turn the engine using the alternator rather than the pinion starter.

Obviously it isn't "instant" but it is only a fraction of a second, on autmatics that happens at the slightest touch of the accelerator, on manuals it happens as soon as you start to lift the clutch.

I doubt it makes a noticeable difference to a queue of vehicles, even if they all have stop-start.

longer than what? Than it used to be?

Cars at rest are bunched up. It takes a while to move off as they have to, when running, have a decent gap between. My Auris hybrid is quick off the mark since, although the engine is off, it doesn't then start until I'm doing 20mph or so.

On a flat road my car will start to move the moment I take my foot off the brake. Feet on no pedals and it moves.

Probably because at least one of the drivers in front is using their mobile phone, or so my observations would suggest.

Thanks. It sounds like it is just a perception or perhaps a sign of impatience. It's like a queue when I think the person at the front is taking too long or talking too much, then when I get to the front I do the exact same.

The alternator to start the engine? That surprises me.

Honda motorcycles were doing that 60 years ago…

If I'm not at the front of the queue, it also re-starts the engine when the front parking sensor notices the car in front starts to move forward.

Perhaps, in these hard times, another issue is that being gentle on the accelerator can save a few pennies.

Chris

That is clever!

Ah, your stop-start works like that? I learned about that design fairly recently. The only cars with stop-start that I've driven (Honda CR-V, and a VW Golf hire car) have used the starter motor - at least I presume it's the starter motor because it's the same starter-motor whine as when I start the engine from cold with the key. Mind you, leaving a cylinder at TDC and injecting fuel and firing that spark plug doesn't work with a diesel. ;-) I suppose if the cylinder was still hot enough, the explosion could still be triggered when a dose of fuel is injected, even if the compression that produced the hot air in the cylinder was some time before.

I find that I can always have the engine running, ready to set off, well in advance of the light turning green. That's what the red-and-amber phase is for: a "get ready" signal - clutch down (which restarts the engine), select first gear, hand on handbrake, foot on accelerator, ready to do the standard and completely instinctive three-control juggling of clutch, handbrake and accelerator once the lights go green. And of course, the further back you are in the queue, the longer is the delay between being ready to set off and actually being able to start moving.

On my Honda, it is the act of *pressing* the clutch down which restarts the engine, rather than the act of *releasing* it from the fully-pressed position after engaging first gear. That means the engine is already running and doesn't have to start in the few milliseconds between starting to lift the pedal and it reaching bite point.

So you hold it at rest on the footbrake, rather than applying the handbrake until you're ready to start?

Maybe I'm unusual in still doing it the way I was taught for my normal and IAM tests - "footbrake to stop the car, handbrake to *stay* stopped".

I *hate* people who dazzle me at night by leaving their brake lights permanently lit while they are stopped ahead of me in a queue. So I won't inflict that on anyone else. The only time I keep by foot ont he brake is if I;m the lst car in the queue, to make it clear that I'm stationary; once a car stops behind me, I come off the footbrake (having applied the handbrake as soon as I came to rest, as normal).

Highway Code Rule 114: "In stationary queues of traffic, drivers should apply the parking brake and, once the following traffic has stopped, take their foot off the footbrake to deactivate the vehicle brake lights. This will minimise glare to road users behind until the traffic moves again."

My car is designed to do what you (and I) dislike ... when I come to a halt, what would normally be the parking brake symbol (P) lights up in green rather than red, indicating that the car is holding the brakes using the ABS pump (not the electric parking brake)

I can take my foot off the brake pedal, but the brake lights stay on, until I either press the accelerator to set off again, or shift into neutral.

Ditto mine (Renault). Though you can disable it with the A (autobrake) switch down next to the P (parking brake) switch.

As the autobrake only works while stationary, I don't know why it needs to leave the brake lights on.

nib

Well I could press the P button, which puts it in neutral and applies some sort of brake.

Mine has a foot pedal for (what Americans call) the parking brake, not a handbrake. If I'm stopped at the lights I press the P button which engages a parking pawl in the transmission and prevents the car moving, but is not intended to hold the car when parked on a slope. If I'm parked on the flat I often don't use the parking brake when parked.

Theo

I have an automatic and can hold the car at lights on hte handbrake and still outpace the ones with the foot on the footbrake.

But don't you have to be right up the car in front's **** for the front parking sensor to detect the car? I don't normally pull up that close but will try it once and see if my auto does the same.

Malcolm

You only need one person at the front to have applied their hand brake when stopped and also have no idea how to read the road or the lights such as seeing the pedestrian crossing indicators turn from green to red or seeing that the cars from the other adjoining roads have stopped because thay have just got a red light.

It seems to be the result of many drivers not looking further ahead than the car in front, so they are not ready to move when that one does. As for automatics, mine does 0-60 in 7.8 seconds. The previous one was 0-60 in 6 seconds, but the V8 engine only did 19mpg.