Well I have succumbed to an Audi S8, 1997 vintage and have had it converted to LPG (47MPG equivalent at the moment). It’s got the auto tip box on it. When waiting at lights do I put it in neutral and put the hand brake on (as I do at the moment), or do I just sit there with it in drive with the brake pedal down? I feel the former is better, especially if there is someone behind at night, as I hate having to look at brake lights when someone is in front of me with the brake lights on. Just wondering on whats best for the box, but the etiquette matters as well I suppose.
Bill
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Leave it in drive with the handbrake on? anything providing you don't sit with your foot on the brake pedal!
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D and Stick brake on. Cover the brake pedal until the lights change.
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Neutral and handbrake - less stress both for the car and for anyone behind you - unless you know you won't be there for a long time.
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Assuming it's traditional auto, It's probably neither here nor there from a wear point of view whether it's in N or D when stopped with the handbrake on - changing in and out of drive will cause some wear, whereas leaving it in drive will probably just put heat into the ATF with no mechanical wear as such, so that being the case I always went for handbrake + drive when I had an auto. Also avoids the inadvertent snatch that sometimes happens when moving from N to D and trying to get away smartly.
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Most of the cars here in Australia are autos. Most people just stick them in drive and leave it there till they park. At the lights they just put their foot on the brake. Almost every car you see stopped at the traffic lights has the brake lights on. No one ever comments on being dazzled by them.
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Most of the cars here in Australia are autos. Most people just stick them in drive and leave it there till they park. At the lights they just put their foot on the brake. Almost every car you see stopped at the traffic lights has the brake lights on. No one ever comments on being dazzled by them.
That's how I drive autos too. I can't imagine there being any advantage in changing to "N" every time you stop. The whole point of automatics is that you don't have to bother - just select forwards or backwards, and press the go pedal or stop pedal!
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The advantge of handbrake and N is to stop you hitting the car in front should you be shunted from behind - same is true for a manual car. If you hold on the brakes when you are hit from behind your foot is forced of the brake pedal and you shoot forward. If you are in D in an auto this is potentially worse than being in 1st in a manual, a manual you will stall an auto won't. I use handbrake and N in the Audi. Using P locks the gearbox and clutch - being hit from behind in this scenario and forcing the gearbox to mvoe when locked I imagine could cause serious damage.
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Most of the cars here in Australia are autos. Most people just stick them in drive and leave it there till they park. At the lights they just put their foot on the brake. Almost every car you see stopped at the traffic lights has the brake lights on. No one ever comments on being dazzled by them.
And EVERY driver in America does the same.
MTC
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You can warp brake discs by braking very heavily and then holding the brake hard on once you have stopped, the discs get hot however the area not clamped by the pads cools much more quickly than the area that is clamped by the pads and the disc distorts. This is common on some big heavy cars, the driver brakes up to some lights from 80 and sits with it in drive with his foot on the rather hot brakes. If you have used the brakes hard then always release them as soon as you stop.
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Hi Cheddar, I'm not doubting the veracity of your post - but why isn't that an issue in America wher the overwhelming majority of cars are autos and every single one (seemingly) holds the car on the footbrake at red lights?
MTC
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Hi Cheddar, I'm not doubting the veracity of your post - but why isn't that an issue in America wher the overwhelming majority of cars are autos and every single one (seemingly) holds the car on the footbrake at red lights? MTC
Hi Murph,
It is not exactly a common occurance anywhere and in the US with lower speed limits and IME less traffic light GP's etc it is perhaps rare though I am sure not unknown.
Regards.
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True, but with traffic lights being very common in built up areas in the US, no engine braking from an auto and the cars being well and truly on the Porky side, these are all things that would show up as problems on the disc warpage front.
MTC
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Reckon it happens in the US, perhaps no more, perhaps no less. Not exactly a common prob though a consideration for auto drivers in particular.
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I'd never even heard of it / come across it before I came to HJ !
I'm not sure if I'd change the way I do the whole traffic light thing any way. My car has a "foot brake" and a hand release by my right knee and it just isn't as handy as a good old fashioned handbrake - so I sit at the lights with my foot on the brake. As for dazzling folk, surely thats a bit of a non starter - loads of buses / trucks have auto boxes and I can't ever recall being disturbed by their tail lights.
MTC
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If I want to stir a stick around I would buy a manual. If I dont want to bother with such stuff I buy an auto. Wiggling the stick backwards and forwards on an auto is like buying a dog and doing your own barking.
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TourVanMan TM < Ex RF >
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I suggest you read the driver's handbook and do as it says.
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You can warp brake discs by braking very heavily and then holding the brake hard on once you have stopped,
Not that old wives tail again.
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Not that old wives tail again.
Clearly at least one old wife is well versed in thermodynamics and metallurgy.
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Yes an old wives tale.
1 in normal use the disk dont get anywhere near hot enough to cuase a problem
2 Your knowledge of thermodynamics will lead you to conclude that a significant proportion of the generated heat is stored in the pads/caliper assembly therefore making the temperature differential insignificant.
3 As an old wife versed in metallurgy you will also appreciate that modern twin ventilated disks, being a sandwich supported by vanes in the centre means that the direction of heat stress cant easily warp the disks due to heat differential.
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TourVanMan TM < Ex RF >
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2 and TVM is talking out of his botty - flawed point.
1 & 3 stand tho
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TourVanMan TM < Ex RF >
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> 1 in normal use the disk dont get anywhere near hot enough to cause a problem >>
Slowing 2000kgs + of car and passengers from say 80ph to standstill means a hell of a lot of kinetioc energy is transfered to heat by the brakes.
3 As an old wife versed in metallurgy you will also appreciate that modern twin ventilated disks, being a sandwich supported by vanes in the centre means that the direction of heat stress cant easily warp the disks due to heat differential.
>>
This is answered by your flawed point 2 "that a significant proportion of the generated heat is stored in the pads/caliper assembly" therefore ensuring that the are of the disc clamped by said pads retains significan heat for far longer than the open-to-the-air vented section of the disc.
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and of course, removing your foot from the brake pedal increases te airglow int eh vicinityof the disc by how much?
when brake discs were solid there used to be a problem, but this was as much due to teh quality of their contructin as anythig else. I've not seen a warped vented disc in many years.
--
I read often, only post occasionally
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