Safe Speed Forums

In Ralph Nader's book "unsafe at any speed" (out of print now, but well worth a read if you are interested in cars, design, safety) there is a chapter about one car model that had R and D next to each other without anything inbetween, and the fact that it caused shed loads of fatalities.

I believe it was quite revolutionary at the time, the now "standard" order of gears in an auto was developed as a response to the book.

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COAST Not just somewhere to keep a beach.

A young loner on a crusade to champion the cause of the innocent, the helpless, the powerless, in a world of criminals who operate above the law.

Many years ago I was given an automatic as a hire car never having driven one before

I also had to contend with an almighty traffic jam on the M42 and learned the hard way that putting it into neutral when you would normally do so in a manual car is not the right approach

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"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed

Thanks Prof! Some good info there on the finer points of gearbox decision-making.

It's no surprise that people become distracted in their cars, there are so many things to play with while you're behind the wheel. Electric windows, electric mirrors, electric roof, heated seats, economy/winter/sport settings, and that's in a 10 year old car! All I want to do is go for the shopping, but I feel like I'm vising Cape Canaveral.

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Less Kodak, more Kojak.
In times of deceit, telling the truth is a revolutionary act.

For a few days last week I had a Honda Civic IMA Hybrid which I road-tested. That has a CVT with a NiMH battery pack between the back seat and the boot, regenerative braking and more electronics than Appollo 8 could dream of.

I wrote a fairly comprehensive report if anyone wants to see it.

Yes please

Never been in one myself but people have reported riding in a Prius as somewhat scary because of the absence of normal engine sounds.

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"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed

Here you go.... http://www.safespeed.org.uk/forum/viewt ... 7627#97627

Yep the day that goes wrong out of warranty is the day it goes to the scrap yard...

Its worth remembering that the battery packs do not have reliable life expectancy data. Some deep discharge batterys used in electric vehicles can only stabt 1000 charge cycles. When that give up the car is beyond economic repair.

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Speed camera policy Kills

You do wonder who will be interested in a 10-yo Prius or Civic IMA

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"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed

If the battery, CVT belt(s) and motor brushes are replaced, it should be no worse for reliability than any other car I think.

But is replacing the battery likely to cost more than the value of the car? A 10-yo car is likely to be worth only £1000 or so.

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"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed

Battery technology is improving at quite a rate. It is possible that a replacement battery will give a big boost if accompanied by a "tune up" ROM

Just seen this:-

The brake lights are higher intensity, better to attract the attention of the car behind.
If you are shunted forward, the foot brake will limit the amount you travel forward.
If you are shunted forward, the good sized gap will reduce the chance of you hitting the car in front

ONLY if you are the last car in the Q!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

just realised the missing point in my post above, it was "when at the rear of a queue of stationary traffic".

Missed this too! Must be the whisky!

The handbrake on my auto Omega won't hold at much above idle, and a Merc E class auto I got my hands on a few years ago similarly had no difficulty in moving off with the parking brake fully applied, with just the slightest of dabs on the accelerator. I had the Omega handbrake serviced last year which made no discernable difference to its holding ability, and whilst I've no idea what the service history was like on the Merc, given it had only just reached a 4 figure mileage I'm assuming it was mechanically about as sound as when it left the factory.

So the question is - should a handbrake be expected to hold an auto when in gear at anything above idle, or even at idle?

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Chris

I should expect it to be able to hold the car when its at idle as from previous posts the torque convertor should not be delivering anything to the drive wheels at idle (or have I misunderstood there - I've never driven an auto). As for anything above idle? The handbrake in a manual must be able to withstand a small amount of applied torque when releasing the clutch for a hill start for instance. If the handbrake in an auto cannot do the same (and yes I realise that its not necessary to hillstart like that in an auto), then I would be concerned as to its ability to hold the car when parked on a hill for instance.

I still maintain that you should be able to leave the car in D with the handbrake applied and expect it to stay still.

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Science won over religion when they started installing lightning rods on churches.

The hand brake on my XJR and XJ40 will hold the car at idle in gear, but only if applied firmly.



Both cats will pull away in forward or reverse with the hand brake fully engaged without even noticing.



This is not the case, the hand book for most (all) automatic cars I have bothered to read, describe a slow manoeuvering technique where you hold the car stationery on the foot brake, then slowly release, this will then allow the car to start creeping. The speed is controlled by the footbrake not the accelerator.

The other common use for this is in very slow moving traffic and motorway jams. When in stop start traffic, I sometimes just take my foot off the brake and let it crawl at idle to the next stop point.

A rather rambling way to say that at idle an automatic transmission will still want to move the car.

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Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways - Beer in one hand - kebab in the other - body thoroughly worn out, screaming WOO HOO What a Ride

Thanks for the corrections!

The point remains though that the handbrake should be able to hold the car. And the point also remains that people stopped in traffic with their brake lights on is DAMN irritating!

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Science won over religion when they started installing lightning rods on churches.

Not true. As satared above the torque converter is biased to give some torque at idle to stop the car rolling back when starting on a hill.

Some autos use a powder clutch. This is different to a torque converter but still has some forward bias.

A hand brake can hold a car in most idle conditions but because the torque converter is a torque multiplier you can get massive torque generated as the engine comes off idle. Easily enough to overcome any hand brake. If you don't believe me just try it.

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Speed camera policy Kills

On my E class there was an alarm if you moved off with the parking brake (to give it its proper name) applied - so they obviously didn't expect you to notice from the drag!

but only in the UK...