Coming up to London the A31 from Winchester is a series of fast-ish dual carriageway bits interspersed with sneaky hidden roundabouts over crests and around bends. Tonight's study showed most drivers applying the brakes, or at least having their foot on the brake pedal, continuously from the moment they needed the brakes until they stopped at the roundabouts. Presumably they feathered the pedal gradually as needed until coming to a halt.
My technique is to press down a bit harder but not so as to cause a passenger any discomfort - then lift off, apply again and so on maybe 3 or 4 times until I've stopped. Am I kidding myself it's better for cooling and better for pad/disc longevity ? It's the same energy that needs to be burned off after all.
PS Not long ago I had my first new set of front pads fitted at 76,000 miles.
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Most drivers brake too much IMO. My wife is a perfectly competent driver who hardly ever crashes into anything, but even on familiar roads comes straight off the accelerator firmly on to the brake, making me want to ask (I rarely do as I know what's good for me) why she didn't just lift off 100 yards earlier, saving fuel and brakes, given she's not on a racetrack or even going particularly quickly.
I am still on the original discs and pads at 85,000 miles despite the franchised dealer telling me I needed new pads at 25,000 and new both at 50,000, the result being I wouldn't trust them to wash the car much less service it. I do tend only to touch the brakes once though.
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On all too many occasions I briefly think someone on a side-road is not going o stop and run into the side of the car. They brake late and hard. Who taught that?
And approaching traffic lights some numpty will overtake/pass even though we can all see the lights were read. They then break hard but having anticipated the road ahead (and therefore slowing) you just accelerate.
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>>On all too many occasions I briefly think someone on a side-road is not going o stop and run into the side of the car. They brake late and hard
Not clever on any level. Worries and distracts other road users. An unexpectedly slippery surface, perhaps in the wet or caused by loose grit or spilt diesel, and they're over the line.
Universal hazard rule applies - get the thing to the right speed and under control before you get there. Often it's the quickest way - you can give more attention to negotiating the junction maybe without even stopping, picking a line round the bend or whatever and make better progress overall - or so it seems to me. Far more satisfying than an abrupt halt and a scrabble for first gear as well.
Not that I haven't done my own share of pointless rushing in arriving at this enlightened state!
Last edited by: Manatee on Tue 6 Jul 10 at 23:01
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>>why she didn't just lift off 100 yards earlier
I'm into neutral long before then. I'm a pensioner and petrol's not cheap!
Last edited by: bathtub tom {p} on Tue 6 Jul 10 at 23:28
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I'm firmly with manatee on this one. It's the tactics I use in a car and certainly have always used in a lorry.
There's no point in having a heavy vehicle if you're not going to use that weight to slow you down for free.
I was taught to treat it like traffic lights in reverse......Green for accelerator, Amber for hovering between the two pedals and Red for brakes.
I'm amazed at how many people still accelerate up an uphill sliproad off the motorway only to brake sharply at the end when the slope could have reduced their speed by doing nothing.
Pat
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>> >>why she didn't just lift off 100 yards earlier
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>> I'm into neutral long before then. I'm a pensioner and petrol's not cheap!
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Why? Surely you should syill be in gear until you come to a halt? You'll use more fuel coasting in neutral than just lifting off I'd have thought
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"On all too many occasions I briefly think someone on a side-road is not going o stop and run into the side of the car. They brake late and hard".
A few bad winters with ice on the road and they will not...
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>>despite the franchised dealer telling me I needed new pads at 25,000 and new both at 50,000
Picking up Manatee's comment, this happens almost every time we have one of our extended family's cars serviced. Usually goes like this: "you need new discs and pads" "they look alright to me" "no, we measured the thickness of the discs and it's x which is close to the manufacturer's limit of y, so would be below the limit if left until the next service, could shatter under heavy braking, won't be liable for the consequences etc etc" "Oh, alright then". Unless you have a set of calipers, it's hard to check this, let alone argue with it. I can't remember the last time only the pads needed replacing either - the discs seem to wear as fast or faster than the pads (according to the workshop) and always seem to need replacing together.
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Its all down to planning and anticipation, you either have it or you don't.
Or more likely have never been taught it.
Last edited by: Old Navy on Wed 7 Jul 10 at 09:34
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I was taught that braking several times before a junction was bad practice. Brake once and gently rather several hard jabs. It also stops the driver behind running into the back of you, if al he sees is red lights on constantly rather than blinking on and off.
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I've said this before, so I'll say it again :)
The brake pedal is like a tap that empties fuel straight onto the road. You use hard-earned money to buy expensive fuel, convert it into kinetic energy, and then chuck it all away every time you touch the brakes.
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>> It also stops the driver behind running into the back of you, if al he sees is red lights on constantly rather than blinking on and off.
I dunno, i can imagine a person just failing to notice brake lights, away in a day dream, the brake lights are on from a sensible distance back but still they just plough right into you only realising when its too late.
Blinking brake lights would hopefully penetrate their day dream and get them thinking "what's the lunatic in front up to, he's one to give a wide berth".
I do tend to stop in 2 stages.
Also if i'm last to join in a queue of traffic i leave a reasonable gap with the car in front which i close only when i see the next car approaching behind slowing down for me.
The skill / harder bit is in setting off at the right time once i'm sure they're stopping, to close my gap so that the driver behind doesn't need to mess about and can just feather the brake slightly and roll on the extra distance i've now left. On the motorway if they don't leave a gap i probably wont close mine. 70mph -> 0mph == his car and me are getting a bad shunt.
Although i'll be on handbrake at traffic lights, if the car behind seems to be a 50/50 whether they'll stop i'll blink my brake lights. Not so fast that it looks like im panicing but so it looks like i've just be readjusting myself in the cabin. Same theory, brake lights on then off the on etc. should hopefully wakeup a day dreamer.
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>>if left until the next service, could shatter under heavy braking, won't be liable for the consequences etc etc
>>
One manager I worked with had no interest in cars beyond " It is transport".
He had been commenting re brakes felt odd so eventually got somene to "sort 'em out"
The next time I saw him he had a very large shim to show me.
The disk was almost non existant. thin as a sheet of paper and had detached itsself.
I assume the other disk had retained some braking capability.
So this was one disk that did not shatter but survived - well sort of!
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>> The next time I saw him he had a very large shim to show me.
>> The disk was almost non existant. thin as a sheet of paper and had detached
>> itsself.
I remember looking at someone's Renault (11 i think it was) years ago and i found similar, the discs were down to feeler guage thickness, how they didn't shatter is an all time mystery, brake backing virtually wore through too...the noise and feel through the pedal must have been dreadful, how can people not realise something is so wrong.
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To put everybody's mind at rest, I am not pursuing a policy of reckless endangerment ;-)
My disks are not thin (I can see by the edge) and they do get measured by the independent chap who services it, who has all the vehicle data.
The dealer's reasoning on the disks was that they were pitted - the invisible kind of pitting apparently.
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>>To put everybody's mind at rest, I am not pursuing a policy of reckless endangerment ;-)
Quite the opposite, I'm sure, Manatee. It seems to me that replacing discs and pads at almost every service visit is becoming "standard practice". All I can do is try to feel how much the discs are worn at the lip that forms around the edge, but this is a poor argument when you get the inevitable phone call mid-morning telling you the measured thickness. I suppose the only way to check is to invest in a set of calipers. Anyone know what sort would be best and how much?
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>> "On all too many occasions I briefly think someone on a side-road is not going
>> o stop and run into the side of the car. They brake late and hard".
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These and the ones who stop at the give way then roll forward as you approach are my favourites, following traffic permitting, I just slow right down as I pass them so they have to wait a nanosecond longer before they pull out and an even better effect is when there was a gap behind me that they could have come out into, but has now been closed by following traffic, if they hadn't "made ;0)" me slow down. Heh Heh!
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I'm in the anticipate the hazzard ahead, adjust speed and go past it at the appropriate speed, only using the brakes gently brigade... certainly not "covering" them or "on/of/on/off"...
Cliff, you summarised it well!
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I don't think braking 'wastes' fuel per se - you have to convert the kinetic energy of the car to waste heat somehow to slow it down, be that via the brakes or other parts of the car heating up. There's probably a minor difference between staying on the power a bit longer and braking than lifting off earlier and slightly less braking, but it will be small. What does waste fuel is lack of anticipation and acceleratng into hazards then having to brake to match the speed, or stop for something you haven't seen (like traffic lights!), or frenzied acceleration to a new speed (although there is some debate on which is better from an economy point of view. Getting into top gear at 15mph doesn't help either - peak engine efficiency occurs at peak torque so it's best to run at peak torque if you can (natural on a diesel as it's usually around 1700-2000 rpm.....!).
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>>I don't think braking 'wastes' fuel per se - you have to convert the kinetic energy of the car to waste heat somehow to slow it down, be that via the brakes or other parts of the car heating up.
You need to think about this some more ;-)
It's about how much the brakes, or other parts of the car, need to heat up.
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>>I don't think braking 'wastes' fuel per se
I fully agree - it's midleading.
What wastes fuel is unecessary use of the accelerator pedal. Whether you slow via overrun or via the brakes makes no difference whatsoever.
However, it's advice that is trotted out in almost every "10 Tips for saving fuel" article in papers and magazines, and as such has been accepted as a truth.
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I know we've had this discussion before, but while it may true that it doesn't matter how you slow down, it does follow that if you are doing it on the overrun rather than using the brakes, you will have saved fuel simply because you have had to get off the accelerator sooner.
The simplest way to implement that is to try and minimise braking. It works. I am currently getting 50mpg in mixed motoring from a diesel SUV with a combined cycle figure of 42.
Scenario 1 - approach roundabout at 70mph, 100m away off thottle and straight on to brake, arrive at roundabout doing 20mph.
Scenario 2 - approach roundabout at 70mph, 300m away off throttle, 50m away light touch on brakes, arrive at roundabout doing 20mph.
The second involves much less braking and uses less fuel. The two may not be cause and effect but they are synonymous in practice; therefore it is not helpful in the least to argue that reducing brake usage does not save fuel.
I do not need you to agree but you can if you like ;-)
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EDIT: Disregard post...
I always read it as the implication that you don't use brakes as much. To enable you to not brake as much, the implication is you're not hitting the accelerator as much.
It still stands on it's on right if you only read into it verbatim as you guys are doing. Modern Car coasting in gear to a stop over 100 yards uses almost no fuel because nothing is injected until blaa blaa blaa everyone knows the rest ;-)
EDIT: Manatee was faster on the draw ;-)
Last edited by: CraigP on Wed 7 Jul 10 at 13:39
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Why not attack the problem directly, and say avoid unecessary use of the accelerator pedal?
I think the avoid braking advice is needlessly indirect, and potentially dangerous if carried out with excessive zeal.
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>>> I think the avoid braking advice is needlessly indirect, and potentially dangerous if carried out with excessive zeal.
Not to mention excrutiatingly annoying when the pink fluffy dice in front saves his 0.1mpg at the cost of the 20 cars behind who couldn't predict his behaviour (no crystal balls) and have been left scrubbing speed neeedlessly early and maintaining a lower speed via throttle.
Last edited by: Webmaster on Mon 12 Jul 10 at 00:34
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Of course I don't mean the brakes literally use fuel - it's a figurative expression.
Needing to use the brakes hard is a symptom of having used the accelerator unecessarily.
Once you have built up all that speed, the efficient thing is to use the energy usefully, eg to climb the next hill. Being forced to ditch it in a hurry shows lack of foresight and anticipation.
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I brake harder than I need or used to do to clean the rust off the discs. If I don't they get in a right rusty mess.
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>> I brake harder than I need or used to do to clean the rust off
>> the discs. If I don't they get in a right rusty mess.
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I probably do enough miles not to worry, but I do normally brake hard at least once a day, as I have to leave the A41 racetrack onto a very short downhill exit slip. Perhaps if I didn't, I'd have more risk of rusty discs or seized calipers? No need to do it all the time though - a bit like driving the long way round to keep your DPF clear!
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I fell off my chair with shock at the "85,000 miles on original brake pads" comment.
I don't think I've ever managed more than a quarter of that, on any car. Thanks to modern pad material, it's usually a set of discs at the same time too :-(
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I can assure you it's true. And I don't think I'm a particularly slow driver either, though I have backed off a bit since the company stopped paying for my fuel a year or so back!
West Herts/Beds/Bucks isn't an especially hilly area, which helps I dare say. In the past I've certainly been much harder on brakes.
What does surprise me is the very good condition of the discs - no grooving, and no sign of warping/vibration at all.
Maybe the original equipment components are better than average quality. I ran the previous CRV for 52,000 miles without any brake replacements; the predecessor Scorpio estate had two sets of discs between 19,000 when I got it and 85,000 when it went.
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>> West Herts/Beds/Bucks isn't an especially hilly area, which helps I dare say. In the past
>> I've certainly been much harder on brakes.
I take it your not including High Wycombe?
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>>I take it your not including High Wycombe?
Now and again. Not exactly Snowdonia though ;-)
I used to live in the kneehills of the Pennines, and occasionally had to explain to Head Office why my 895cc Polo only did 27mpg!
Last edited by: Manatee on Wed 7 Jul 10 at 20:25
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I fell off my chair...
Then don't get too comfortable yet, DP: I had the S60's original front pads replaced in May after seven-and-a-half years and 108,000 miles. I meant to ask to see the old ones because I suspect there was still some wear left in them but I reckoned that it's a once-and-once-only job for this car so best just get it done.
The car did its last 50,000 miles in 32 months, mostly on the M40, so it's done much more going than stopping. But before that I was living and working in one town, so it did its share of short journeys too. I'd credit the long brake life partly to my habit of using third gear in town, using engine braking for fine control of speed; no points on my licence either.
};---)
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>> I brake harder than I need or used to do to clean the rust off the discs.
Surely there can't be a need to do this, unless the vehicle is used only to go a tiny distance, and that infrequently - the build-up of rust doesn't happen quickly.
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Rust on discs seems to occur incredibly rapidly in my experience, particulalry in humid weather as at present. Quite common to see a light covering if one of the cars has not been moved over a weekend.
Not sure I'd bother altering my braking to clear it except perhaps if car was left during a fortnight's holiday. I'd also need to carry some weight in the back (to exercise the brake regualtion valve) in ordeer to effectively clean the rears.
The car is a Xantia.
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Saw a comfort braker today, not seen one in ages.
Very very gentle braking application, but very frequently, either for longish periods or rapidly blink blink blinking away (but not really slowing down).
Avg speed ~33mph. Found her a real challenge to overtake safely. I couldn't get very close to her because of the twists turns dips and rises in the road -- i'd be out of sight for anyone approaching the corner at national speed limit but there i'd be immediately round the corner at 30mph. Having to hold right back approaching corners so that i could be sure of a full exit out of the corner on the other side.
Then because of that it'd be a mad dash of rapid accelerating to catch her up only to find it's not safe to overtake followed by approaching the next blind dip, rise, twist or turn.
The annoying thing isn't the speed it's the fact that she has very little chance of needing an insurance claim. Travelling at ~30mph she would rapidly pick up a follower who would be the cushion in the case of a rear shunt from someone going too fast round a corner they couldn't see round or over a blind summit. I'm not disputing the fault of the person going too fast for the conditions, just the fact that it's very hard for someone who doesn't want to be in an accident regardless of fault, to keep their NCB.
I love a rant i do. Almost as much as being right ;-)
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I do try to be quite careful about using the brakes, preferring gravity etc to do the work for me. Leaving the M56, I can lift off nearly half a mile before the junction as it slows to a 50 limit and then goes downhill briefly.
However, normally on slip roads I brake once, gently, at the start to be certain the brakes are working and then more firmly as I come to the end.
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To make sure the brakes are working? I could just about understand this in the days of Marinas that would overheat in any traffic jam, and whose window would fall out if you slammed the door, but has anyone here suffered even a partial brake failure in a properly maintained car built in the last 20 years?
Sorry to pick on you, AF, but what you describe sounds more like superstition than sensible roadcraft.
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I've always thought brakes were there to be used.... never understood why you'd adopt a no brakes driving style. My discs always look like polished chrome.
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It's a good move to test your brakes after a wet motorway stint, wet discs don't work very well. I almost learned that the hard way a few years ago.
Last edited by: Old Navy on Fri 9 Jul 10 at 08:19
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>> Sorry to pick on you, AF, but what you describe sounds more like superstition than
>> sensible roadcraft.
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Been in a vehicle where the brake servo failed on the motorway and not discovered until the slip road. Wasn't me driving but suspect it took the driver a long time to get the brown stain out of the seat.
It's only a tap at the beginning of the slip road. Better than getting to the end and finding out...
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It's a good idea to have a tentative prod when leaving a motorway or similar fast road where you might not have touched the brakes for an hour or two. Gets you the feel, perhaps of the road surface as well as the brakes, and as has been mentioned if it's raining hard they could be wet - something I've noticed from time to time, not being one of those people who's on and off the brake all the time on a motorway.
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Having had the heart stopping moment when the pedal dropped to the floor coming off the A1M down Welwyn (more likely, it was over 30 years ago) or Stevenage Nth slip road in a Wartburg, i don't blame anyone just having a feel.
Luckily the Knight's handbrake was one of the best i've ever used.
Seeing how some drivers approach such junctions relying totally on admittedly powerful brakes, i wonder how long they would have survived in the older generation of cars with non servoed basic brakes.
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Braking Style - Manatee
