"Turn off" hill-assist on manual trannies?

This might seem like a dumb question, but I currently don’t have the opportunity to experiment with this feature on a test drive. I’m wondering if there’s a quick way (i.e. much faster than the 2-3 seconds it’ll take to do it on its own) to defeat the hill-assist now present on the manual E90s. I’m not sure how it’ll work out, but in places such as the steep inclines of San Francisco, I can imagine times when I would much rather prefer the guy in front of me to have this feature instead of me. Often times, it’s easy to notice a rookie or tourist in the city by how much they roll back starting off on steep hills. When I notice someone in front of me struggling too much upon advancing, I quickly step into the clutch to roll back with him, coming to balance my car within six inches of the guy behind me, granting all possible space to the front car. I reckon the occasional slight wear of my clutch is minor compared to the scratches on my front bumper. Two-three decades ago, when there where a lot more manual drivers, one could frequently witness this phenomena: an out of town driver not knowing how to manage his manual car on hills, and 2-3 experienced city drivers behind him, who’d immediately roll back in unison giving the rookie a full car’s distance to get his act together (upon failure, there would be a colorful exchange of words…). Anyhow, would double clutching, or a momentary shift to 2nd before reengaging 1st allow one to begin rolling faster? Now that I think about, parallel parking on hills will also be cumbersome if one needs to wait 2.5 seconds to begin rolling in the opposite direction of the gear once the clutch goes in, short of actually shifting. Among my long list of why I prefer a manual to an auto, quicker parking into tight spots on inclines is one of them; I hope I don’t have to give it up.

The feature ONLY activates if all the following are true:

a) You are at a complete stop
b) The clutch is pressed
c) The breaks are pressed
d) The car is in first gear

Then, when you lift your foot off the breaks, the feature will activate. The length of time it stays engaged seems to depend on the steepness of the hill. (Note that if you are facing down-hill, the feature activates if you're trying to back up the hill). I think it's simply brilliant and would help you A LOT with parking due to it working in reverse as well if needed.


So, if any of the above conditions are not met, the feature doesn't activate, so you can take your pick as to how to make it roll. Also, as soon as you start moving forward (in the forward-driving uphill scenario), the feature is disengaged. So, for example, if you start moving slowly forward then notice someone rolling back, you can do your clutch slipping without worrying about it activating. I think I would love it in a place like SF

Shift to neutral. So in theory a double clutch should work.

Although it's a neat gimmick, I didn't particularly think it was a great feature, while driving my e90 around. The clutch takeup is much better than the car it replaces, and it beging to grab nice and progressivly, with the pedal almost right off the floor.

Originally Posted by LarryN

Although it's a neat gimmick, I didn't particularly think it was a great feature, while driving my e90 around. The clutch takeup is much better than the car it replaces, and it beging to grab nice and progressivly, with the pedal almost right off the floor.

Well, it is not a great feature if you like using your hand breaks on steep hills or if you like rolling back a bit at first before you go forward (which is inevitable on some hills no matter how fast the clutch grips).

Originally Posted by silverado

Well, it is not a great feature if you like using your hand breaks on steep hills or if you like rolling back a bit at first before you go forward (which is inevitable on some hills no matter how fast the clutch grips).

Should you ever need to use the hand brake to stop from rolling back?

Originally Posted by 330maybe

Should you ever need to use the hand brake to stop from rolling back?

Yes, if you are not starting up. The hill assist feature is designed to detect when you are about to try to move the car up a hill from a stand still and it engages the breaks for you. At all other times, you are on your own.

For background knowledge, starting a manual transmission car up a hill usually requires using the hand breaks to keep the car in place while the first gear is being engaged enough to support the car. In fact, it is part of a standard driving test (if you do it in most countries other than the US which require taking the test with a manual transmission car). It's a basic technique that any manual transmission driver needs to know.

Could you tell me what "double-clutching" is? I've heard the term mentioned in connection with trucks though I dont know what it means in that context either!

Originally Posted by dsbmw

This might seem like a dumb question, but I currently don’t have the opportunity to experiment with this feature on a test drive. I’m wondering if there’s a quick way (i.e. much faster than the 2-3 seconds it’ll take to do it on its own) to defeat the hill-assist now present on the manual E90s. I’m not sure how it’ll work out, but in places such as the steep inclines of San Francisco, I can imagine times when I would much rather prefer the guy in front of me to have this feature instead of me. Often times, it’s easy to notice a rookie or tourist in the city by how much they roll back starting off on steep hills. When I notice someone in front of me struggling too much upon advancing, I quickly step into the clutch to roll back with him, coming to balance my car within six inches of the guy behind me, granting all possible space to the front car. I reckon the occasional slight wear of my clutch is minor compared to the scratches on my front bumper. Two-three decades ago, when there where a lot more manual drivers, one could frequently witness this phenomena: an out of town driver not knowing how to manage his manual car on hills, and 2-3 experienced city drivers behind him, who’d immediately roll back in unison giving the rookie a full car’s distance to get his act together (upon failure, there would be a colorful exchange of words…). Anyhow, would double clutching, or a momentary shift to 2nd before reengaging 1st allow one to begin rolling faster? Now that I think about, parallel parking on hills will also be cumbersome if one needs to wait 2.5 seconds to begin rolling in the opposite direction of the gear once the clutch goes in, short of actually shifting. Among my long list of why I prefer a manual to an auto, quicker parking into tight spots on inclines is one of them; I hope I don’t have to give it up.

Originally Posted by deburn

Could you tell me what "double-clutching" is? I've heard the term mentioned in connection with trucks though I dont know what it means in that context either!

Get ready for some long winded explaination.....

Do you know what rev-matching is?

I'll throw in my 2 cents. Having visited SF on many occasions, I don't think using the hand "BRAKE" (correct spelling) is necessary, but the hill assist feature basically eliminates the need for it.

The original poster made some very good points about being able to roll back along with the person ahead of them is they were rolling back into him. I have a suggestion: Leave a little more room in front of you, so they have room to roll back... That's what I do. You shouldn't be within 2 feet of the person anyway (even in SF), and if they roll back more than 2 feet, there's not much you would be able to do (since there is probably someone behind you closer than that anyway). You can only roll back so far with someone behind you.

The original poster also lamented not being able to roll backwards immediately while parallel parking... This is probably the worst problem you will encounter with the system. 2 seconds is not that long but it can seem like an eternity when you are trying to park. If you lift the clutch slightly, the hill assist is defeated, but also if you are in reverse, it will allow you to roll backward, so either method will allow you to roll back right away. Even with hill assist active, however, I somewhat doubt the safety of rolling back within 2 seconds, as you probably have not had time to look behind you before rolling back right after coming to a stop. The 2 seconds the system is active will give the driver enough time to turn around and verify that there is no one in their way before rolling back.

By the way, a better way to avoid rolling back (in a car without hill-assist) is to use the "heel-toe" method on the brake/accelerator. You should be able to hold the brake and depress the gas slightly with your right foot, and manage the clutch with the left in such a way as to not need to have to let the clutch out before moving your right foot to the accelerator. The BMWs pedals are set up great for heel-toe, (yet another of the things that make our cars great driver's cars) but unfortunately, many other cars are not. I drove a lot in SF in my old 83 GTI and used the heel-toe method and never rolled back at all (unless I meant to of course). I would never buy any Manual Transmission car that was not set up well for heel-toe. NEVER!

I grew up driving in San Francisco and have driven many different cars in this city (almost all with manual transmissions) for my entire life. I know how to heel and toe, etc. It's true, that most of the time you don't need the handbrake. That's true 99+% of the time. However, you can find yourself in circumstances on some of the steepest hills in this city where you would be crazy not to use your handbrake. I don't know how well the hill assist capability of the E90 will work in extreme circumstances. I know I will have my hand ready on the handbrake when the time comes to find out. No shame in that. The handbrake is our friend.

Originally Posted by Athos

I grew up driving in San Francisco and have driven many different cars in this city (almost all with manual transmissions) for my entire life. I know how to heel and toe, etc. It's true, that most of the time you don't need the handbrake. That's true 99+% of the time. However, you can find yourself in circumstances on some of the steepest hills in this city where you would be crazy not to use your handbrake. I don't know how well the hill assist capability of the E90 will work in extreme circumstances. I know I will have my hand ready on the handbrake when the time comes to find out. No shame in that. The handbrake is our friend.

I agree, there is no shame in using the handbrake. You do what you have to when you have to.

In my experience, the hill assist feature is definitely strong enough to hold you on the steepest of hills. I believe it is calibrated to hold the car no matter how steep the hill. I think this is a great feature for those that do live in SF, Pittsburgh, and Seattle, where there are steep hills that normally would require the handbrake at times. I disagree with the original poster who says that it is a bad feature because people will roll back into you and you can't roll back quick enough to avoid them. Leave more room!

If everyone had this feature, no one would roll back into anyone!

Heh, so much for "end of discussion".

Originally Posted by CC 330i

By the way, a better way to avoid rolling back (in a car without hill-assist) is to use the "heel-toe" method on the brake/accelerator.

I was wondering when someone will bring this up as the "magic" technique. People do crazier things with their cars, so it could qualify as a ftd thing to do with your bimmer if the handbrake is too boring for you. I suppose that is only thing h&t will be good for when it becomes obsolete on autocross tracks. On a car without the hill assistance, that is.

Originally Posted by CC 330i

I'll throw in my 2 cents. Having visited SF on many occasions, I don't think using the hand "BRAKE" (correct spelling) ...

Ouch... Every once in long while the fact that English is my second language catches up with me! When it does, it typically happens with something that simple, but which happens to fall in an area in which I haven't done much writing before. Nevertheless, it can make one look quite ignorant. This is definitely the first time I've had to write about brakes in my life.

Originally Posted by Moderato

Get ready for some long winded explaination.....

Do you know what rev-matching is?

Nope!

I noticed this thread went all over the map and after the first couple of replies, it never addressed the original question; it just demonstrated lack of definitions by some and poor reading by others.
I simply wanted to know from those who already have the manual version of the car, what's the quickest way to force the car to roll on an incline once the hill-assist feature engages. It’s not a single judgment on whether the feature is good or not. It’s just that I can think of scenarios when I don’t want to be held up. Consider having to shoe-horn yourself into a very tight spot on an incline where you’ll have to do multiple back and forth maneuvers. In an slushbox, you’ll have to constantly shift between D and R; in a manual, you can use both hands to spin the wheel quicker, step into the clutch, roll, brake, spin the wheel in the other direction, release (engage) clutch and drive opposite to the roll, brake, step into the clutch, roll, brake…etc. If it’s done only once it’s no big deal, if it’s multiple times, the manual is much quicker than the auto, as both hands can be used to spin the wheel stop-to-stop without having to go to the shifter. In a flat area, it’s a mute point, but I can actually park faster into awkward tight spots when there’s a 5% incline as I don’t need to shift at all. Albeit, such scenarios occur seldom, but more to some than to others. Once the hill-assist engages, if simply releasing the clutch pedal to the catch point and then pressing it back down, instantly removes the brake pads from the disks, then it’ll be an easy thing to get used to.
BTW, I do leave the proper space between the car in front of me and myself, and quite instinctively adjust it depending on parameters such as hill grade, make and model of the vehicle in front, etc. But leaving too much space between cars is also bad driving, it adds to congestion and backs up lights several blocks down. Yet, being able to apply a defensive manuvouer to quickly roll back is not a bad thing, considering it can be used to readjust the initial space before another car drives up behind. Imagine leaving a proper distance on Nob (snob) hill to the car in front, yet it’s one of those prideful people who insist they can manage any hill without using the brake and don’t have a hill-assist feature. In such case I’d like to defeat my hill-assist quickly and roll back as much as possible once they stall and come at me.
Incidentally, those who claim that simultaneous braking while accelerating from a steep hill isn't necessary to prevent rolling back if one just knows how to release the clutch sufficiently before letting off the brake and stomping the gas might do well in defining "steep hill." To get an idea of what someone in SF (or Wellington, or other cities with *real* hills) thinks of “steep,” consider going to the steepest street in your town. While parked, open a water bottle and fill a cup with straight walls up to half its diameter from the rim (e.g. if a mug has a 3” diameter, do not fill the top 1.5”). Now, very carefully open one of those awesome cup holders your car has, and place the cup in it as gently as possible. If you haven’t already spilled water by now, you’re not on a steep hill. You’re still below 26 degrees; we have a few 30’s around here. If you’re above that angle, and can master the simultaneous brake technique, you could take a sip from the cup and drive forward without spilling any more. The sine of 30 deg = 0.5. If you still don’t get the picture of what that implies in your flat neighborhood, drive to the top floor of a multi-story parking lot and look for a small car that weighs half as much as yours. Fasten a steel cable around its bumper and yours, back up against it and push it off the building. Hold your car solely with your brakes at the edge of the roof, such that if your roll back a few inches you also go off. Now, try your no-brake technique and move forward. Other than the inertial moment of your own car on the flat surface, it’ll be roughly equivalent to a 30deg hill. If you don’t go over, you’re likely to be a nuisance stopped anywhere as your idle is set absurdly high.
Personally, I prefer the toe-and-heal technique to the hand-brake; I think it’s a smoother transition when all four brakes are engaged and the weight is taken off the springs on the back. Yet, for good reason, the hand-brake technique is what is expected in SF. On a rainy night with wet leather soles, toe-n-heal can easily go haywire and the right hand should be on the hand-brake instead of the cell phone (unless you have a Detroit special with the E-brake release deep under the dash, -who thought that one out?!). Yet, I’ve met women with small feet who are remarkable at toe-healing with 4” stiletto heals. Unlike most people who actually “heal” with the side of the foot, they control the gas pedal with the tip of their heal such as not to scuff the side of their $300 designer shoes. Of course, this is for starting from a hill; I’ve never been in a car (nor want to) where someone on stilettos was toe-healing for rev matching to negotiate a curve on the limit.
Wondering if this horse hasn't been beaten to death by now.

For the person who asked what rev matching and double clutching is, I’d suggest you google it outside this forum. I’ll offer a 2 cent, 2 min reply, but I’ll likely get flamed for writing anything and you’ll get lots of conflicting posts. In it’s shortest explanation, to double-clutch, you shift from gear to neutral, momentarily release your foot from the clutch pedal, and step back into the clutch as you shift to the next gear. For rev matching, tap the gas pedal before releasing the clutch so that the engine’s speed is close to what its load will be when you release the clutch. That is, the rpm’s of the engine should be similar to the rate of turn of the selected gear that is being turned solely by the car’s wheels while the engine is disconnected from the transmission. You pretty much do this when regularly working through the gears at moderate rates, yet those who’re into performance driving will have to work more diligently at it when driving hard, particularly for instance, when cornering and not wishing to upset the balance of the car while down shifting by introducing an abrupt engine break. Yet, knowing that they’ll need the lower gear after the turn, they’re already on it when they exit the corner. Hence, the need for toe-healing the brake and gas, as they’re simultaneously slowing down coming into the curve and need to rev match the engine. Double clutching is hardly ever done today, as the simplest manual tranny in a car (for big rigs, it’s another story) has synchronizers that help engage each gear. Yet, together with rev matching, it was a way to help smooth the transitions between gears in older cars (pre 70’s). However, if you have a very high mileage car and find it difficult to engage a gear, it’s respective syncro is likely worn, and double clutching/rev matching will help enter the gear. I’ve never been into high end performance driving, but many of these techniques in their simple form I had to learn as a teenager having nothing other than my beat up bug in SF. The bungee cord type hand-brake cable was worthless in holding the car on a hill so toe-healing was a necessity. Moreover, the old ‘match-box’ tuned points and over stripped 10mm bolt that held the distributor in place only lasted a few hundred miles before losing half the power of the 45HP engine. Hence, if I was on 3rd gear and had to make a right turn and go up a modest hill, I’d either have to stop and go into 1st gear and stay there, or without slowing down too much, forcefully shift from 3rd to 2nd on the turn by double clutching and toe-healing to rev match and climb up at twice the speed on 2nd, at about 20mph. Those were the days…

Originally Posted by dsbmw

I noticed this thread went all over the map and after the first couple of replies, it never addressed the original question; it just demonstrated lack of definitions by some and poor reading by others......

Incidentally, those who claim that simultaneous braking while accelerating from a steep hill isn't necessary to prevent rolling back if one just knows how to release the clutch sufficiently before letting off the brake and stomping the gas might do well in defining "steep hill." To get an idea of what someone in SF (or Wellington, or other cities with *real* hills) thinks of “steep,” consider going to the steepest street in your town. While parked, open a water bottle and fill a cup with straight walls up to half its diameter from the rim (e.g. if a mug has a 3” diameter, do not fill the top 1.5”). Now, very carefully open one of those awesome cup holders your car has, and place the cup in it as gently as possible. If you haven’t already spilled water by now, you’re not on a steep hill. You’re still below 26 degrees; we have a few 30’s around here. If you’re above that angle, and can master the simultaneous brake technique, you could take a sip from the cup and drive forward without spilling any more. The sine of 30 deg = 0.5. .....

Wondering if this horse hasn't been beaten to death by now.

Yes, this thread went all over the map. Isn't that part of the fun? In an effort to continue the beating....

I am the first to agree that SF has steep hills, been there, driven there. We don't see much over 12% locally, unless we go off road. SF has several hills at 30%. Fillmore, quoted by another poster above, is steep, but one recent bicycle race graded that hill at 10% average grade, 18% peak grade. There are some 30% hills, I am sure. But that is still only 16 degrees, not 30 degrees. Also, the math may need adjusting in your otherwise excellent (and very graphic) coffee cup example. If you have a 3" diameter cup, and fill it within 1.5" of the top, and tip it, it seems to me that the spill point will be 1.5" rise over 1.5" run (since the run is half the diameter). This means spillage would result on anything over a 100% grade, aka 45 degrees. This is why coffee never spills when driving steady, only when braking or accelerating. Gotta say though, that the visualization was great.

Originally Posted by deburn

Nope!

Everything dsbmw wrote is acurate, however I would suggest doing a search on this forum if you want to know more. There have been some good discusions on here about it.

To the OP regarding your ORIGINAL question.
If you don't like the feature get it programmed out. It is that simple.
This feature isn't just on manuals it is on all of the E90 series.
It will cost you to take it to the dealer to have this done but once done it is gone forever.
I am working the coding on our cars so I can modify the systems to suit my needs and hill assist is gone as soon as I finish...

The way I normally drive, the hill assist doesn't come into play. On the few occasions where I want it, it seems natural and easy to engage it.

'Not sure what the big deal is.

And, yes, this has to hold the record for oldest resurrection.

Originally Posted by fun2drive

To the OP regarding your ORIGINAL question.

Originally Posted by ProfessorCook

And, yes, this has to hold the record for oldest resurrection.

And since the OP has only 30 posts and

Last Activity: 10-03-2006 05:01 PM

it is unlikely that he will ever see your answer.

That feature annoyed me at first as well, I never had a car with it before but now that I'm used to it, I love it! If you're on a hill, backing out of parking spot, etc., it holds the car for a couple seconds and allows you to get a nice easy engagement on the clutch. I've been driving MT my entire life and yes I've never needed it before but now that I have it, I think it's a great feature. If you really want the car to roll for some reason, just put the car in neutral and take your foot off the clutch pedal and the car will roll, or just wait the 3 seconds or so for the brakes to release and then the car will roll. The brakes release quickly once the car gets some positive torque going so, I don't feel it's ever invasive at all.