Is automatic dangerous?

Anyone that drives an auto should know that the foot brake must applied when selecting gear from stationary.

But

The auto should also be put in N and hand brake applied when waiting at traffic lights. Sadly a lot of people prove that are incompetent to drive an auto every time they halt at a traffic light.

Why put it in neutral? If you're going to move the lever, put it in park. That usually works properly - unlike some handbrakes, and those who don't apply them properly.

That is going though 2 more notches on the selector and needs the shift button pressing (2>1, R and P).

D > N > *** R *** > P

Flashes the reversing lights which will sorta freak the person behind out. I'm sure they will prefer the blinding dazzle of holding it on brake lights to that.

I occassionally get given a courtesy car with a TCT auto-box and stop-start when mine is in for a service:

- When the car stops the engine stops (in D). - If you apply the handbrake and release the footbrake the engine re-starts. - If you put the car in N and apply the handbrake the engine restarts if you release the footbrake. - If you switch the ignition off you lose all exterior lights and air-conditioning.

In other words, the car is *designed* such that you sit there with your foot on the brake and the selector in Drive when stationary in traffic. My personal preference would be for it to cut the engine when the handbrake is applied and re-start when it's released with the footbrake applied. I don't like it, but there it is.

On my car it is fully forward for park, fully backwards for drive. Probably easier than finding neutral. And of course you have to press the button when selecting anything from neutral.

The reverse lights on mine have a slight delay. Move the lever through reverse and they don't light. Dunno if it's intentional, or just the speed it takes a relay to make.

That is pointless and contributes to faster wear of the bands in the auto box, by requiring them to jump every time. The auto box is designed to idle in Drive. Handbrake on, no problem, selector in Neutral, no.

Not in MY owners manual. In any drive gear the engine is loaded by the transmission as proven by the fact that car will MOVE if the brake is released. That load (~5bhp) still exists when the car is stopped and becomes heat in the slush drive as that's the only place it can slip. To produce the extra 5bhp that makes the car creep for parking the idle air valve is opened by the ECU to hold the idle at 850rpm, that load uses FUEL. In "N" the load is removed and the Idle air valve shuts down a bit more reducing fuel use.

• DRIVING PRECAUTIONS

• Shift into "N" position and apply the parking brake when at a standstill for longer than a short period.

I read that as pulling up at a traffic light that I know is going to be red for a full cycle.

• When stopped on an upgrade. Use your brakes (selector lever in the "N" position) to hold the vehicle in place to prevent overheating the transmission.

It is quite clear that "N" should be used when stopped.

And on the OPs original point.

• Keep the engine at idling speed while shifting from "N" to any driving position.

Additional *CAUTION*

• Cold engine idle speed is high, so use caution when shifting into a forward or reverse gear before the engine has warmed up.

• Avoid revving the engine while the vehicle is stopped. This could cause unexpected vehicle movement.

Further on it expands that to "if in a drive gear or damage the engine if in "N" or "P"."

The service brake may be rated at well over 500bhp but most cars can pull off and drive with the handbrake on. Handbrake application pressures are not anywhere near those of a servo foot brake. With a torque converter factor of between 2 and 3 and a 1st gear around 3:1 an auto can easily override the parking brake.

I would call one cycle a short period, but that is my interpretation.

On the rest of the post, I have no arguments, just this one.

Why do autos need a park position shouldnt neutral be sufficient

Why do autos need a park position shouldnt neutral be sufficient

With a manual, you could leave the car in gear if you were unsure about the handbrake, or if you wanted extra hold on a slope. P (or L as it was once called) is a way of achieving the same for automatics. At one time it was done by engaging two gears at once, hence lockup,or L. I'm told things have now moved on from that.

Steve

Wot do steering wheel nor accelerator?

As it is in a manual.

Or if you put it into first in a manual.

or first in a manual.

Moved on?

A toothed wheel splined on the output shaft with a pawl that engages in P.

Not foolproof.

P has always been P. L stands for low - first gear. But on an auto, the gears can't engage with the engine stopped, as they need hydraulic pressure, which comes from an engine driven pump. Engine not running, no connection between it and the wheels. Which is why you can't tow start a modern auto. (some older ones could - they had two pumps, one driven off the propshaft.

So leaving an auto in gear when stopped is the same as leaving it in neutral. Hence the mechanical lock called park.

1959 Mini with single leading shoe drum brakes at the front.

Actually rather better than the later twin leading shoe type - less prone to fade. And ok if you push hard enough. Especially for 30 bhp. ;-) I had several Minis with those brakes and they were just about adequate when in good nick.

The TLS were better if you adjusted them really carefully; rather worse were the early Cooper discs with no servo, and a hydraulic intensifier.

I once built a 'shopping car' for the (now ex) wife using an 850 Mini Traveller shell, with an MG 1100 engine, and Cooper 'S' final drive ratio. On rev-counter calcs, it would hit just shy of 100mph. (The speedo only went to 85 or so.) That had single leading shoe brakes, and was err... interesting to stop!

Chris

Well quite. All my Minis were 850 vans and to be honest unlikely to exceed

70 mph by much on the level regardless of what the speedo said. If at genuine 100 mph the same brakes (and on a heavier vehicle) would have been fun.

I hope that isn't how she became "ex".... :-)

Sadly not!

Chris