Regen vs Mechanical Braking

[fred88]

I honestly can't remember everything he spoke about. There were a few takeaways that have stuck though, namely:

• The IAM was about teaching people to avoid other people's accidents, Ie, among other things, don't get involved with a bad driver and end up having their accident.
• Light on the throttle, light on the brakes, this encourages thinking ahead as has been said above.
• He got penalised on his IAM exam for not overtaking a very slow driver when there was a safe opportunity to do so.

It was an interesting group but ended up moving to a venue too far away for me to join.

 

[TonyHSD]

15 hours ago, Don Mac said:

Did he also use phrases like "Lift your vision" and "a good drive should be boring"? (Americans might say something like "slow is smooth, smooth is fast") I have met police drivers who took pride in never having to stop on "blue light" drives through heavy traffic.

It's all about planning ahead. If you look up & anticipate what is coming you can (almost always) avoid having to make any sharp changes to speed or direction, and you can also hold on to your momentum/speed into roundabouts etc. (like Andrue said).

I imagine that a good proportion of the people on this forum (well, me at least) are attracted to Toyota hybrids because they are so well suited to this style of driving.

True. Very well said 👌

[Geoff W]

20 hours ago, Bernard Foy said:

When I bought my first car (heap of scrap) all those years ago I as an old guy for advice on driving. His reply was “drive as though a glass of water is sitting on the bonnet and try not to spill it” 👏. In other words do everything smoothly.

There was an app on my first Toyota (59 reg) called "Glass of Water" which actually simulated exactly that! What happened to all those apps? 

[Dylanfan]

Years ago I had a library book out about the IAM test. One of the thinking I remember was TT, that was tyres & tarmac, when pulling up behind a car in a queue you should be able to see their tyres on the tarmac.

I also picked up that the police were trained to use their brakes, not the engine/gearbox to slow down because brakes are much cheaper to replace, I don’t know if they still teach that now.

[Don Mac]

1 hour ago, Dylanfan said:

I also picked up that the police were trained to use their brakes, not the engine/gearbox to slow down because brakes are much cheaper to replace, I don’t know if they still teach that now.

I think they do, but I would qualify it to mean using the brakes to slow down when approaching an obstacle (presumably at speed because they're the police...) rather than changing down a gear. (thus avoiding clutch wear) As I recall police/IAMs teaching was to brake/accelerate to the desired speed, then select the correct gear for the speed (block changing) - rather than always going through every gear.

Using engine braking by lifting off the throttle or changing to a lower gear on a steep downhill are better than using the brakes unnecessarily.

[Yugguy1970]

Since getting a hybrid I'm very conscious of pointless acceleration, and maintaining speed to avoid too muxh braking.

But there's always times you need to brake rather than coast down.

[Cyker]

With the gear thing, if you're doing it right you shouldn't need to downshift to engine brake because you'll already be in the right gear - This is why MMT and DSGs will never be as fast as a good manual driver in real life driving: Sure they can change gears with millisecond speed, but we can see there's a hill or tight corner ahead and will have already shifted well in advance rather than e.g. in the braking zone for the corner!

The block change thing is very situational; If you're accelerating gently, you should need to go through all the gears. If you accelerate from e.g. the lights like I did in my old D4D, then going from 2nd to 4th or 5th would be a regular occurrence  

Lately I've found it very noticeable when the mechanical brakes cut in - I suspect they're getting a bit rusty  

Normally it's pretty smooth and progressive, but lately it's been much sharper, presumably due to the extra friction from the rust, and I sometimes have to back off them when they engage which is very annoying and makes it hard to apply correct pedal pressure because I'm pressing a certain amount under regen then the friction brakes cut in and the car is suddenly braking much harder than it was before. I wish the system could sense braking force and blend them better in that situation.

[TonyHSD]

3 hours ago, Cyker said:

With the gear thing, if you're doing it right you shouldn't need to downshift to engine brake because you'll already be in the right gear - This is why MMT and DSGs will never be as fast as a good manual driver in real life driving: Sure they can change gears with millisecond speed, but we can see there's a hill or tight corner ahead and will have already shifted well in advance rather than e.g. in the braking zone for the corner!

The block change thing is very situational; If you're accelerating gently, you should need to go through all the gears. If you accelerate from e.g. the lights like I did in my old D4D, then going from 2nd to 4th or 5th would be a regular occurrence  

Lately I've found it very noticeable when the mechanical brakes cut in - I suspect they're getting a bit rusty  

Normally it's pretty smooth and progressive, but lately it's been much sharper, presumably due to the extra friction from the rust, and I sometimes have to back off them when they engage which is very annoying and makes it hard to apply correct pedal pressure because I'm pressing a certain amount under regen then the friction brakes cut in and the car is suddenly braking much harder than it was before. I wish the system could sense braking force and blend them better in that situation.

Yes these are the first symptoms of brakes need service. The next ones are scored brake discs and then like my case recently burning smell and even more trouble. Ten cause of the issues are rain and wind and the salt on the roads. The catalyst of the process is the regenerative braking and always cold brakes. Ten results moisture locked Inside the slide pins and inside the callipers pistons boots.
So what happens then: you are pressing the brake pedal and the car slows down mostly with brake by wire regenerative braking, pressing further and rear brakes should engage as pressure is send to the rear callipers but not strong enough to open the piston or piston opened and pushes the inner pad against the disc but because the slider pins are stuck the outer pad can not push against the outer side of the disc., then you push even further and the front brakes engage sharply as they are directly driven by the hydraulic force of the master cylinder, the results sudden braking, sharp transition between regenerative and actual brakes . 
Services required: dismantling, cleaning and lube the pins, check pistons for normal operation, clean pads and shims, put back all together, job done. 

[Cyker]

TBH I think it's nothing that serious, just needed more use; Been up and down Muswell Hill a few times today and the brakes seem back to normal  

Will probably start again tho' as I drove through a lot of heavy rain and puddles on the way home (So much splashy!  ) which will probably rust them up again...

One downside with having the steel rims is it's much harder to visually see the condition of the discs, but maybe they will have shielded them from the worst of the water!

[TonyHSD]

Same, last night I had to go through deep waters at some country lanes in the fields of Buckinghamshire. No problem with deep water but then after I noticed a clicks when manoeuvre and use the brakes. Perhaps from the ball joints, as those were definitely immersed in water. I hate going through waters but had no choice. 150 miles later and everything dried out and no clicks, hopefully not a long term problem. Same happened before after doing the same. Brakes as usual, rust forms every day but then clean away until it stops and the discs start to look scored. Soon will do a brake services , tyre rotation and deep alloy clean. 👌

[Gerhard_Corolla]

You can definitely feel the changing process between regenerative braking and the subsequent intervention from the front brakes and then the rear brakes; rust can enhance the feeling on the brake pedal indeed...

 

Yesterday, for the first time, had to make an emergency hard braking, and I could feel the different processes coming into action. I couldn't feel the car creeping forward at any moment, just a gradual increase in braking power, but the feeling was not nice. Late at night I drove along a park, which is depressed, and have stairways flowing directly into tight sidewalks, so it's difficult to see if anyone approaches or intent to cross the street. I just saw a white blob with my peripheral vision running towards the street, step on the brakes hard, and happily managed to not hit what we later saw was a dog. At first I thought it was a child, my pants feel off...

 

Just for that type of scenarios, I take weekly a longer route than I should to drive the car on highways, where you can brake hard from higher speeds to try to keep up your rear brakes in good shape. Something not easy to do in winter...