f3racer wrote:Is the IAM's justification for slowing down entirely using the brakes and then making a single gearchange really valid?
f3racer wrote:I always deliberately try to avoid the use of brakes for ecomomic purposes and reduce sleed using the gears where possible.
f3racer wrote:I always deliberately try to avoid the use of brakes for ecomomic purposes and reduce sleed using the gears where possible.
martine wrote:f3racer wrote:I always deliberately try to avoid the use of brakes for ecomomic purposes and reduce sleed using the gears where possible.
So when you're slowing and dip the clutch and go from 4th to 3rd to 2nd, you are using more fuel than keeping it in 4th, clutch up and using the brakes. This is because modern engines have a fuel cutoff in this situation i.e.no fuel is being used. As soon as you put the clutch down to change gear, fuel has to be used to keep the engine going.
Other more important (in my view) justifications include:
* keeping both hands on the wheel for longer (safety and more accurate steering)
* more balanced (4 wheels are braking, if you use gears to slow only 2 (unless it's 4wd)
* easier to adjust rate of slowing precisely
Makes sense to me.
Gareth wrote:
Next, whatever method you use to slow down the 'wasted' fuel is that needed to subsequently accelerate, so using gears is effectively no different to using brakes in this. If you wanted to be the most economic you'd try to slow down as slowly as possible, possibly using neither brakes nor gears but just lifting off the accelerator. You'd probably need to work out whether it is better to keep it in gear with the clutch up, (normally shuts off the fuel), or depress the clutch to minimise friction losses, but neither approach is anywhere close to the aims of UK advanced driving.
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daz6215 wrote:Isn't slowing down by lifting off and not using the brakes 'acceleration sense' as advocated by Roadcraft? It does actually require a lifted vision and good anticipation to achieve successfully, which is all part of advanced driving.
Gareth wrote:daz6215 wrote:Isn't slowing down by lifting off and not using the brakes 'acceleration sense' as advocated by Roadcraft? It does actually require a lifted vision and good anticipation to achieve successfully, which is all part of advanced driving.
Lifting off, slowing for lower speed limits apart, is a subtle application rather than the main method of slowing down. Excessively slow slowing is what some people mistakenly mistake for smoothness but denies the aim of sustained good progress.
daz6215 wrote:Gareth wrote:daz6215 wrote:Isn't slowing down by lifting off and not using the brakes 'acceleration sense' as advocated by Roadcraft?
Lifting off, slowing for lower speed limits apart, is a subtle application rather than the main method of slowing down. Excessively slow slowing is what some people mistakenly mistake for smoothness but denies the aim of sustained good progress.
Depends on the definition of 'progress'!
Slow to Flow and all that!
GJD wrote:Roadcraft says "Acceleration sense helps you avoid unnecessary braking" [my italics]. It gives two examples: accelerating out of a junction only to have to brake for traffic ahead, and accelerating up behind a slower vehicle and having to brake before overtaking. I don't think Roadcraft advocates trying to generally avoid the brakes. Indeed, four pages after the acceleration sense bit, it says "Use the brakes when you need to make more than a gradual adjustment to your road speed."
The no brakes game is a good exercise for getting your vision up and planning ahead, but I wouldn't drive like that all the time. By permitting myself to incorporate more than just gradual adjustments to road speed in my plan, I think I improve both progress and flow.
daz6215 wrote:time it right and you may arrive at that point when its cleared, be it by using the brakes or acceleration sense, they are both advocated!
Gareth wrote:daz6215 wrote:time it right and you may arrive at that point when its cleared, be it by using the brakes or acceleration sense, they are both advocated!
Both of which are far from the method advocated by the OP.
daz6215 wrote:Maybe I misinterpreted your explanation, It looked like you described acceleration sense in your answer to the OP and then said neither were advocated in advanced driving!
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