DRCC acceleration settings.

[SDR]

I have a 24MY Corolla TS 1.8 (140).   When I initially went through all the meter settings I set the DRCC acceleration setting to the lowest of the  three available settings.   Thinking being, new car, running in, and if it's too sluggish I can just use the throttle to increase pace.

Yesterday it got its first real workout.   I found myself in a situation such that, from a crawl, I suddenly had a clear road ahead (with DRCC set to 55mph).   I was expecting very gentle acceleration and was thinking that I might need to give the throttle a prod to get it going.

Not a bit of it.   Acceleration was 'sprightly', way quicker than I was expecting.    Revs up, hybrid gauge into the power quadrant.   With less than 500 miles on the clock I wouldn't have been pushing that hard if I had been driving 'manually'.    Checked the mirror after a few seconds, a car that had been a few metres behind me was now way back.

Which left me wondering.   Is this as it is supposed to be or do I have a software issue that needs sorting?    And if this is normal for the car, just what happens if I change the DRCC acceleration setting to medium or fast?

Any thoughts please?

[sportse]

I have the same model, it normally accelerates using maybe 10/20% into the power band which gives very good acceleration.  but I find the dcc acceleration setting to not make much difference. 

it accelerates well, but there is quite a long delay before it starts to accelerate once the road in front clears. Mine is always set to fast now. 
 

I’ve also found it doesn’t keep the speed going downhill that well, and can go over the limit you’ve set by 1 or 2 mph and not slow down for ages so I have to override it by setting the speed down another couple of mph before then putting it back. 
 

no worries about the revs on your new car, ‘running in’ isn’t really a thing now on a couple of new cars I’ve had unless you have a high performance car. When I bought mine all I could find was a recommendation try not to to use full power in the first 500 miles, but you could if you wanted. 
 

the power band can have fairly low engine revs at the start of the band as it will be mixing the electric and petrol motors. Quite a bit of the response feeling is due to the electric motor. 

[SDR]

Thanks for the reply.   I don't suppose that there is anything actually wrong with the car, it's just that with the DRCC acceleration setting at 'slow', I was surprised at the pace.  

From this (very limited!) experience, and your comment about the setting not making much difference, I am thinking that it is the delta between the car's speed and the DRCC set speed that most likely influences the rate of acceleration.   This would have been about 50mph and the car seemed keen to close the gap as quickly as possible.

What you may not want to hear is that, once the road had cleared (the car in front turned into a side road), I didn't notice any delay before my car started to accelerate.   Maybe that's just subjective/expectation, but it seemed to me to be quite quick to get on with it.

[sportse]

On a previous VW I had, the setting affected how fast the car responded as well as the level of acceleration for the DRCC  but I haven’t noticed much difference in mine between the settings. 
 

it’s fairly quick in the Toyota but it does seem to wait a second or so just to be sure that the car in front has really moved into the other lane before accelerating. 
 

I would like it to keep the set speed accurately, it should be easy for it as it can use regen braking to do so but it does drift above a few mph. 

[SDR]

26 minutes ago, sportse said:

 

it’s fairly quick in the Toyota but it does seem to wait a second or so just to be sure that the car in front has really moved into the other lane before accelerating. 
 

I would like it to keep the set speed accurately, it should be easy for it as it can use regen braking to do so but it does drift above a few mph. 

Perhaps that explains the difference.   This was single carriageway, the car in front of me hadn't changed lane (where it might still have been visible to the camera or radar), it had turned off into a side road;   and fairly smartly too as it went through a gap in the oncoming traffic.   So it would no longer have been visible to my car.

I have found that it typically only reaches about 1mph above the set speed when going downhill.   However, I live in Cambs.   On the edge of the Fens.   Gentle undulations are the order of the day.  I've not really driven it down anything steep so far. 

[Chuffmonkey]

I am intrigued. I use Dynamic Cruise Control, I assume that's DRCC. Are you saying the car will come to a near stop if something in front slows down enough? Lets say I am travelling at 60 and the car Infront slows to 40ish my car will slow down to match which I experience daily but I normally press the cancel button at that point and use the throttle. If I just let the DRCC do its thing would it bring me to a full stop or a 5mph cruise?

Maybe I need to trust the tech more 😄

[taxidriver50005]

1 hour ago, Chuffmonkey said:

I am intrigued. I use Dynamic Cruise Control, I assume that's DRCC. Are you saying the car will come to a near stop if something in front slows down enough? Lets say I am travelling at 60 and the car Infront slows to 40ish my car will slow down to match which I experience daily but I normally press the cancel button at that point and use the throttle. If I just let the DRCC do its thing would it bring me to a full stop or a 5mph cruise?

Maybe I need to trust the tech more 😄

It will bring you to a complete stop and then prompt you to either resume or press accelerator... Don't think it will do emergency stop. 

[sportse]

1 hour ago, Chuffmonkey said:

I am intrigued. I use Dynamic Cruise Control, I assume that's DRCC. Are you saying the car will come to a near stop if something in front slows down enough? Lets say I am travelling at 60 and the car Infront slows to 40ish my car will slow down to match which I experience daily but I normally press the cancel button at that point and use the throttle. If I just let the DRCC do its thing would it bring me to a full stop or a 5mph cruise?

Maybe I need to trust the tech more 😄

Yes, I use it in traffic jams regularly alongside lane keeping. It's a great aid.

The car will keep 2 seconds (or what distance you set) from the one in front all the way from a standstill to whatever speed you have set on the cruise control.

I can have it set to 40mph and it will crawl along behind the car in front. If the car stops briefly then it will keep active, if it stops for longer it enters freeze mode where you just have to tap the accelerator or resume button to get it moving again.

You do have to keep aware, it doesn't handle people that cut into the gap too well. Lane keeping is best on straightish roads, it also doesn't like sharper bends with concrete walls to the lane. But generally it's very good.

[sportse]

7 minutes ago, taxidriver50005 said:

It will bring you to a complete stop and then prompt you to either resume or press accelerator... Don't think it will do emergency stop. 

Yes, I believe it's limited in how much braking force it can apply. It will warn you if braking that's needed is more than it can do and you have to take over. (If you don't it might trigger the collision avoidance emergency braking as a last resort, but you may still hit the car in front)

I had a Volvo with a similar system, that could only brake maybe 40% of maximum. So you had to be aware that if you came up on traffic much slower it wouldn't be able to handle the braking itself. Could catch people out if they weren't aware of this.

[Chuffmonkey]

I am so used to using DDRC on fairly straight open roads that I never thought about the slower speed elements. Normally I assess the road conditions and press cancel to take manual control or tap the break to gain control again. I need to trust the technology but I also want to remain as aware as possible. 

[Cyker]

1 hour ago, Chuffmonkey said:

I am so used to using DDRC on fairly straight open roads that I never thought about the slower speed elements. Normally I assess the road conditions and press cancel to take manual control or tap the break to gain control again. I need to trust the technology but I also want to remain as aware as possible. 

If it's anything like the one in my Yaris, that's the best thing to do.

Its biggest weaknesses are sensible acceleration and deceleration - It just doesn't understand what buffer space is, so if the car in front shoots off it'll get confused for a second then jump straight into POWER and launch the car off to try and keep the distance to the other car when it really doesn't need to.

Likewise, if the car in front slows, instead of using up the buffer gap to slow down more gradually/gently, it'll try very hard to maintain the distance and go full engine-braking which is surprisingly strong (I think this is a big flaw with the system, as the car slows down very abruptly without brake lights coming on, and it could easily catch out someone following too close behind!), and not use the friction brakes until you're quite close to the car in front.

If the car in front stops very abruptly, more so than engine braking alone can stop you in time with, the AEB will trigger as normal, complete with panicky beeping and the horrible grinding sound as the car automatically and violently brakes to a halt, so the DRCC is quite safe, if not very refined. I'm fairly confident it won't crash into anything it's following, it's just whether I'll get whiplash or bruised ribs from the way it accelerates and decelerates  

 

These re worst case scenarios though - If the vehicle in front is more gentle/progressive, the DRCC works much better and will even bring the car to a gentle halt at a sensible distance to the vehicle in front. It's been great on my section of the M25 lately, as they've reduced it to 3 lanes and imposed a permanent 50mph limit while they waste more of our money adding pointless laybys, and the DRCC has been fantastic as I just get behind a truck, set it to a spacing of 2 and turn it on and it does all the boring traffic crawling for me  

 

[sportse]

My Corolla is almost always using DRCC in the 50mph limits on the M25.

The Toyota system is pretty good, I had a new Honda with a totally unusable system recently. 
 

it wouldn’t brake until the last minute, so brake hard. Then realise there was a large gap now in front so accelerate hard and repeat…  so bad that it would trigger the emergency collision braking!

 I never used it in traffic, even on the open road it would think cars in different lanes were in the same one and randomly brake. 

[SDR]

This is the first car I have owned that has full slow to stop type CC.   On my previous VW Group cars the adaptive (as they call it) CC wouldn't work below a certain threshold speed.   So I did read the manual quite closely...

The way I understand it is that, if I'm in a line of cars travelling at 60mph towards a roundabout on the A1, and everyone slows down normally to a stop, the DRCC will handle that no problem;   but if I am travelling at 60mph with a clear road in front, and approaching a roundabout where there is stationary or slow moving traffic, I need to take control or risk testing the airbags (as it isn't designed to deal with that situation).   

I usually do one 400 mile return trip every month which is A1, or M1, M25, M3 and on.   I think that the DRCC is going to be really useful.

[miks]

gentle throttle on engine beak in period is such a bull**** our grandparents made us believe. Just drive it as you like. 

And yes, CC will slow down to stop if needed and then pick up speed from zero if there is a car infront ouf you.

And the setting you refering to is most probably not acceleration but rather distance you want your car to keep from the car infront of you so the lower the setting the faster acceleration to achive that small distance

[sportse]

8 hours ago, SDR said:

 

The way I understand it is that, if I'm in a line of cars travelling at 60mph towards a roundabout on the A1, and everyone slows down normally to a stop, the DRCC will handle that no problem;   but if I am travelling at 60mph with a clear road in front, and approaching a roundabout where there is stationary or slow moving traffic, I need to take control or risk testing the airbags (as it isn't designed to deal with that situation).   

I usually do one 400 mile return trip every month which is A1, or M1, M25, M3 and on.   I think that the DRCC is going to be really useful.

Yes, that’s right - you just have to be ready to take over if approaching very slow or stopped traffic or if someone cuts in front in slow traffic. 
 

I tested this yesterday by leaving the drcc on for a slip road at 50mph to see what it would do with a stopped car at the end… it would have hit it hard! It  still hadn’t detected the car in front by the time I would normally brake so I took over. Likely because the stopped car was at an angle at the end of the sliproad. 
 

on my car I have the drcc display as the large one in the centre of the dash, so I can see what it has detected and what’s working. 
 

you can even engage the system when stopped or crawling along. Previous cars I’ve had, you couldn’t engage at slow speeds. Just activate the system, then set the maximum speed all while crawling along. 
 

when we had high gusty winds recently it made a 50 mile drive much more relaxing with drcc and lane keeping on. 

[SDR]

2 hours ago, miks said:

 

And the setting you refering to is most probably not acceleration but rather distance you want your car to keep from the car infront of you so the lower the setting the faster acceleration to achive that small distance

If I go into DRCC in the Settings menu, then the sub-menus, there is an option to change acceleration when using the system (slow, medium or fast);  that's how it is on my car anyway.

That's what I was referring to.   Not the button on the steering wheel that gives a choice of four settings for following distance.

[SDR]

2 hours ago, sportse said:

 

I tested this yesterday by leaving the drcc on for a slip road at 50mph to see what it would do with a stopped car at the end… it would have hit it hard! It  still hadn’t detected the car in front by the time I would normally brake so I took over. Likely because the stopped car was at an angle at the end of the sliproad. 
 

on my car I have the drcc display as the large one in the centre of the dash, so I can see what it has detected and what’s working. 
 

I haven't worked out, yet, how far ahead the system detects a vehicle in front.  I don't think it is much more than about 100m.  Probably depends upon conditions and the size of the 'target' too.

I have opted for the single dial setup with the drcc display on the right where it is clear and uncluttered.

[Chuffmonkey]

I tried to trust the function a bit more today 😄. I had it set at 72 and I let it take me down to around 40 mph on a duel carriageway, I wasn't fully comfortable with how the car was acting so I took Manuel control to ensure a smoother slow down. Ill try again tomorrow along the same route to see if Ill let it take me to 30mph. Small steps an all. 

I am so used to the old CC that I am just used to to pressing the cancel button which isn't ideal on busy roads. 

[sportse]

I switch between the one dial and two dial setup, but leave the drcc display in the middle as the map option is so small. 
 

it would be nice if we could have a decent map in the centre of the screen like VW/etc. 
 

 

[SDR]

I started with the two dial display, pretty much as it was delivered, but have settled with one dial, 'smart' appearance, with the dial showing the hybrid indicator as you have.    I don't think that I ever look at an analogue speedo on cars that have a digital version.   I would usually want the tacho displayed but I figured that there wasn't much point on a car that doesn't have any fixed gears.

I agree about the map.   Pressing 'OK' makes it slightly bigger but it still isn't much use.   So I leave 'Settings' in the centre display because it requires less button presses to get to the things that I like to switch off or modify before driving!   I have the adaptive cruise display on the right where you have the energy monitor.

I generally leave the map showing on the large central screen but I have it set up so that I can switch to the energy monitor with one button press.   I don't take much notice of it, because it doesn't actually change how I drive the car, but it amuses passengers!

[sportse]

2 hours ago, SDR said:

So I leave 'Settings' in the centre display because it requires less button presses to get to the things that I like to switch off or modify before driving!  

 

That's what I plan to do too when I change my car, unless Toyota comes up with a way to easily turn off road sign assist/speed limit warnings on the newer models by then.

A software update to do this with one button press would be good, many reviewers are complaining about the new CHR/etc having lots of warnings that don't really work and having to go through settings to turn them off each time you start the car.

[SDR]

6 minutes ago, sportse said:

That's what I plan to do too when I change my car, unless Toyota comes up with a way to easily turn off road sign assist/speed limit warnings on the newer models by then.

I think that this is unlikely to happen because, if I understand correctly, the new Regs are intended to make turning off certain 'safety' features less than simple.   Such that it can be done but not by pressing one bespoke button (as you can with LTA).

I think that I did read, on this forum, of a car (not a Toyota but possibly a Lexus) that had a facility for the owner to create programmable buttons on the centre screen;   each button could be programmed to carry out several tasks with just one press.   That would be a neat solution. 

[sportse]

It would be easy to do via the drive mode switch.

On my last car I had a choice of eco/normal/sport and also an individual mode where I could change various settings to have a custom drive mode such as sport accelerator but normal steering and eco air conditioning.

Just having to press the driving mode switch twice (or once then tap the infotainment screen) to get to an individual mode on the corolla with everything set how I like would be a good option.

[SDR]

2 hours ago, sportse said:

It would be easy to do via the drive mode switch.

On my last car I had a choice of eco/normal/sport and also an individual mode where I could change various settings to have a custom drive mode such as sport accelerator but normal steering and eco air conditioning.

Just having to press the driving mode switch twice (or once then tap the infotainment screen) to get to an individual mode on the corolla with everything set how I like would be a good option.

My last car was the same (Audi) and I also used individual mode set for my preferences.

I'm sure that it would be easy to do but that may also be the problem.   If it was easy to set a driving mode that switched off, or modified, certain TSS settings, would it comply with the new Regulations?

[The auldyin]

DRCC will NOT see a stationary vehicle! It must be moving in the same direction as you. I've been using adaptive cruise control

for over 12 years. Love it, but you must still be in control at all times.