Hill Hold Function

[ElSupreme]

All of the manuals I've driven would creep in reverse or first gear without use of the accelerator, certainly enough for most parking.

They need their clutches adjusted then! :scared:

You will roll, you shouldn't creep with a manual.

And yes we should change the way cars behave, if it is a better way. In my opinion no creep is a much safer fail mode than creeping.

EDIT: I am assuming you don't mean engaging the clutch when idling.

 

[brianoflondon]

They need their clutches adjusted then! :scared:

You will roll, you shouldn't creep with a manual.

And yes we should change the way cars behave, if it is a better way. In my opinion no creep is a much safer fail mode than creeping.

EDIT: I am assuming you don't mean engaging the clutch when idling.

I do mean putting the car in gear and letting the idle of the engine pull you along.

Specifically the last manual car I owned was an Alfa 147 Diesel in the UK. 2.0l turbo diesel and huge torque. Wheel spinning on gear changes from 2nd to 3rd if you wanted. That would roll quite nicely with the clutch disengaged.

My semi auto Honda (manual gear box but with computer controlled clutch) would roll too with feet off the pedals. I'm fairly certain I never used the accelerator backing into my parking spot at home.

 

[jerry33]

I do mean putting the car in gear and letting the idle of the engine pull you along.

Well, that's an unusual definition of creep. Creep in a manual transmission car would mean that the car moves forward when the brake is off and the clutch is pushed fully in. Naturally if you have the engine idling and the car is in first it will move forward. I don't call that creep.

 

[brianoflondon]

Well, that's an unusual definition of creep. Creep in a manual transmission car would mean that the car moves forward when the brake is off and the clutch is pushed fully in. Naturally if you have the engine idling and the car is in first it will move forward. I don't call that creep.

Sorry, wrong term... I guess I'm talking about moving without directly pressing the accelerator. What do we call that, crawling?

My Diesel Alfa could pull away and crawl in 2nd gear without need for the accelerator.

 

[jerry33]

Sorry, wrong term... I guess I'm talking about moving without directly pressing the accelerator. What do we call that, crawling?

My Diesel Alfa could pull away and crawl in 2nd gear without need for the accelerator.

I don't know as I've ever heard a term for that--crawling is as good as any though. And yes, I used to put the Land Rover Series III in low range and just let the engine idle in really bad stop-and-go traffic.

I now have a Prius with creep and I wish it didn't. It wastes a ton of energy (500 Wh for comparison the HID lights use 35 Wh each) when on and is only there to mimic an automatic. Fortunately, the creep will turn off if you press hard on the brake while stopped (you can tell from the display when creep is on), but because the brake is pressed to stop the creep, there is no need for the creep to hold the car in the first place. I'm looking forward to no creep with the Models S. I do expect that there will be a screen function to control this behaviour--even if it doesn't come out till the second or third software release. I have no problem with different strokes for different folks.

 

[brianoflondon]

I can see from the displays on my Renault that the hill hold feature uses no power. It's quite clear it's holding the car on the brakes not balancing the car with power to the motor.

I'm pretty sure I feel this because the motor only drives the front wheels and the brakes hold all the wheels. There is a transition to traction only at the front when the 2 seconds of hill hold ends and the brakes slowly release. If you're on a slight incline, the car will start rolling up the hill. If the hill is really steep you will roll back.

 

[jerry33]

There are hill holding functions. They aren't creep either (which is why they are called hill-holding functions:smile Even with an automatic, creep is a fairly expensive way to implement hill holding. Creep's function is to reduce lag time in an automatic. Other transmission systems shouldn't really try emulate it (in my opinion). A hill holding function would be useful for many people in the Model S. My understanding is that Tesla is working on it but doesn't have it right yet.

 

[strider]

I think Brian's concern is that in an auto or manual ICE, you can keep one foot hovering over the brake while doing slow-speed maneuvers like parallel parking. In a manual you would use your left foot to slip the clutch to get it to "crawl" while your right foot hovered over the brake to stop the car when necessary. In an automatic your left foot would be idle and your right foot would drag the brake to control speed and stop when necessary.

With the no creep Model S, you'd need to touch the accelerator to get it to move backwards and then move your foot back over the brake to stop (since we are all taught that the right foot is for both accel and brake and left foot is only for clutch).

This gets back to my whole, I want it to work like a Segway thing. So when you're backing into a parking space and let off the accelerator the car regens to a stop quickly and holds itself.

 

[William13]

After my test drive today I can say that I have no concern about the creep and hill hold issues.

The car has creep occurring until it is stopped by the brake. No creep then occurs when taking the foot off the brake. I stopped on a steep hill and noted only very little backward movement before using the accelerator pedal to effect a hill hold function that was nearly without forward movement and quickly held still. This was after only 10 minutes of driving. Much better and easier than any manual transmission I have ever used.

 

[jkirkebo]

Sorry, wrong term... I guess I'm talking about moving without directly pressing the accelerator. What do we call that, crawling?

Idling along ?

 

[dsm363]

After my test drive today I can say that I have no concern about the creep and hill hold issues.

The car has creep occurring until it is stopped by the brake. No creep then occurs when taking the foot off the brake. I stopped on a steep hill and noted only very little backward movement before using the accelerator pedal to effect a hill hold function that was nearly without forward movement and quickly held still. This was after only 10 minutes of driving. Much better and easier than any manual transmission I have ever used.

So it does have creep after you let off the accelerator? I'm fine with that.

 

[Fedderman]

During a test drive of the Model S, I had two experiences where the lack of creep was "uncomfortable". Note that my daily driver is a manual (M3) and I'm very adept at feathering the clutch when stopped on an incline, or when I need to move short distances for example when parking.

Situation 1: I wanted to check the turning radius, so I executed a 3-point U-turn on a residential street. The street was pitched from the center to the sides, so after stopping at the first point and putting the car in reverse, it rolled forward close to a foot before I pressed the accelerator. Being inexperienced with this car I was somewhat tentative in applying the accelerator during the maneuver. I'm sure with experience this will not be an issue.

Situation 2: Since I live fairly close to the Menlo Park showroom, I arranged to drive the car to my home and check the fit in our modestly sized garage. Without creep, I found it a bit challenging to move forward an inch at a time for a precision parking position. Again, I'm sure with experience and getting to know the accelerator pedal sensitivity, this will not be an issue. Good news is the car fits, with 6 inches of space at both ends :smile:.

Bottom line, most of the time I would not want creep, but it may be nice to have a "natural" way to switch it on in certain circumstances. Otherwise, in those circumstances I may choose to be a 2-foot driver.

 

[arg]

Note that my daily driver is a manual (M3) and I'm very adept at feathering the clutch when stopped on an incline, or when I need to move short distances for example when parking.

The killer for manual drivers is that there's no handbrake. I had a rental car once that was manual transmission with an electrically-controlled parking brake (and a switch that was deliberately cumbersome to operate so you don't knock it off by mistake). This was a nightmare to drive until I discovered that it actually had hill-hold function: you were supposed to drive away with the parking brake still engaged, which would automatically release as you started to move. This worked, and is presumably similar to the hill-hold that Tesla are supposed to be implementing, but I would still have preferred a real handbrake in that car. At least the Model S won't have the other problem that car had - it was woefully underpowered (for the steep/narrow roads I was driving and the 7 people+luggage on board: it had trouble starting at all on those hills).

 

[markwj]

The killer for manual drivers is that there's no handbrake. I had a rental car once that was manual transmission with an electrically-controlled parking brake (and a switch that was deliberately cumbersome to operate so you don't knock it off by mistake). This was a nightmare to drive until I discovered that it actually had hill-hold function: you were supposed to drive away with the parking brake still engaged, which would automatically release

Renault? I had exactly the same experience. Ludicrous car, and dangerous for a rental fleet. I almost reversed into a wall with one. My brother in law actually got stuck in a stranger's driveway in Italy with his rental.

Not so bad with an automatic and two good feet, but please, Tesla, nothing fancy.

 

[arg]

Renault?

Yes! Renault Espace with a gutless non-turbo diesel.

 

[doug]

Just as long as it doesn't prevent you from pulling off a J-turn.

 

[Robert.Boston]

I am hoping that Tesla can split "hill hold" and "creep". Yes, they both use a similar function: supply some power to the axle independently of the accelerator pedal. My preference, though, would be to have a hill-hold only (both forward and reverse) so that the car would only change its position on my command -- even if gravity has a different view!

 

[woof]

I am hoping that Tesla can split "hill hold" and "creep".

I agree. Hill Hold I'd like very much, not sure about creep. Still want my "trim tab" so I can apply various amounts of regen or creep with a flick of my thumb.

 

[Discoducky]

So, is the consensus that the Creep feature will only apply power to the motor when the brake is released? I'm concerned that power will be applied while the brake is depressed thus reducing range.

 

[arg]

So, is the consensus that the Creep feature will only apply power to the motor when the brake is released? I'm concerned that power will be applied while the brake is depressed thus reducing range.

It is unlikely that power will be applied while your foot is firmly on the brake. Someone with a car could check this out by reference to the consumption numbers.

Relatively likely is some kind of transitional effect - to get it smooth, quite likely they have to power the motor before the brake is fully released. If so, this would theoretically represent a tiny inefficiency and so reduce range - but so small an amount you couldn't measure it.