So yesterday my wife and I went to the Getty Villa. Those not familiar, the entrance driveway is cobblestone and a 8+% grade uphill and the line to get in was moving very slowly, constantly stopping and going. So this made for a jumpy time in the car since the Model 3 rolls back almost immediately after taking my foot off the accelerator and then switching to the brake. I started treating it like a manual using both feet to transition the acceleration and braking a bit smoother. My wife noticed how much I was fussing to keep from rolling back and I told her how I wished the Model 3 has a Hill Climb feature like our X5 where it would automatically engage Hold on a hill like this when you come to a stop. She then just said, “Why don’t you just use Auto drive so it stops and goes for you?” Genius my wife is! She’s smarter than me.
First, your Model 3 does have the Hill Hold Brake function. It’s the H that pops up on the display. Secondly, your wife is not only a backseat driver but is now a backseat Autopilot/TACC driver
When you drive a manual, how do you use the clutch if you have a floor on the brake and one on the accelerator?
Just playing both feet to throttle the accelerator enough to not roll backwards and hit the brake to stop moving. Hold doesn’t engage until you fully hit the brake. With hill climb, the brake automatically engages when you let off the accelerator completely to prevent rollback. My BMW X5 does this, the Model 3 does not, at least in my experience. It will keep rolling backwards if you let off the throttle and don’t engage the brake.
Does it still drift back if you set it on creep? I may have to try that if no one else knows. Not that I would keep it in creep anyway, but curious and might be worth switching in certain situations.
Haven't had a chance to try this as Houston is basically one gargantuan piece of flatland, but I think I saw a comment the other day that suggested creep mode would work here.
Yes, TACC is a way to do this but it can be both aggressive and timid at the same time (hard acceleration/braking vs leaving too much space). I would definitely use it when the stop and go is more stop than go on an incline but, while it may be great for that scenario, it could lead to distraction where the car will start moving again when you completely forgot it was set to do so. I think the better skill to develop and practice is that of one-pedal driving: as the line comes to a stop, remove pressure on your accelerator until the motor vs gravity equation is balanced then, when things start moving again, start pressing until it’s time to relax for the next stop (never fully releasing the accelerator). To me, that is true of all motor vehicles whether automatic, manual (in the right gear you don’t need the clutch for that maneuver), or electric.
My 2005 Honda Accord owner's manual explicitly says not to do this. This is with an automatic ICE car, though, not electric. YMMV
You’ve got me there. It isn’t a recommended technique in ICE cars (for various reasons usually unrelated to engine/transmission/brake longevity - mostly perceived safety issues due to driver skill and a few about erratic compression close to idle, etc.). For manual transmission driving, it is less discouraged and, in some cases, recommended vs riding the brake or clutch; seen some hand brake techniques for really steep scenarios but just another control to manipulate or forget. That being said, one-pedal is a viable skill and, as far as I understand, encouraged in EVs. I’ll admit I’ve only used it a little bit since my area is fairly flat and, as such, the Model 3 doesn’t come to a complete stop in regen only driving.
I wouldn't use the electric motor to hold a position on a steep incline for any length of time because it uses more battery power vs. just using the brake normally.
My advice was based on the OP: Brakes are always brakes but, for stop and go traffic on an uphill, whether you’ve got TACC or not, one pedal driving is a good method to avoid rolling back and keeps you engaged in the process if you have an inclination toward distracted driving. TACC is definitely good for comfort and sanity if you stay alert.
If I understand the OP's original situation, the line would move forward one car at a time followed by a longer pause (like at a ticket booth where each driver has to pay and receive a parking pass or the like). My recommendation is to NOT use one pedal driving (the electric motor) to hold position on an 8% incline (unless it's just for a brief period of time). The more passengers and luggage in the car, the more electricity and heat will build in the motor. I don't think this would cause any damage at all but, in addition to the electricity needed to hold the position of the car, this could also possibly require the cooling compressor to come on to cool the motor and/or battery depending upon temperature. That's more drain on the batteries. I don't think I've seen Model 3 motor efficiency curves at various rpm's and torques but the motors I have seen curves for are not very favorable at 0 rpm or very low rpm. I think this is the bottom of the barrel rpm for efficiency. That implies more heat and battery wastage. Those of us who have a lot of experience with manual transmissions are adept at starting on a hill with a clutch which is one more thing to modulate (and avoid stalling the engine). The electric car makes this a lot easier. That said, the timing is a bit different electric vs. manual transmission ICE so it takes a slightly different "rhythm" which can be re-learned with just a little practice. I'm willing to bet an OTA "hill-holding" software update will eventually alleviate the need to choose between the two methods because it will perform the brake function automatically for the driver. I'm not sure what the reference to distracted driving refers to or what "brakes are always brakes" really means. That just sounds like "fuzzy" thinking to me.
