Cruise control stalk "speed increase/decrease" behavior

Confirmed. If I am doing 55 and do a full up push, I end up at 61. Also, sometimes if I want to drop 5 mph and I push down, it doesn't work.

Oh how I wish I could have the old fashioned "one click up, one click down" arrangement.

While we are at it, please give me another old fashioned setting - allow ME to set the windshield wiper intermittent setting, not some rain sensor thingy.

I'm seeing this too.

Would be nice if the "full stop" push would take you to the next 5MPH increment up or down... so if you're at 58, one full-up would take you to 60 and a 2nd would take you to 65. I think that's how my wife's former 3 series worked -- made it very easy to set the cruise speed quickly...

scaesare said:

With cruise control engaged, pushing the stalk partially up/down should change speed by 1MPH. Check.

Pushing the stalk fully up/down should change by 5MPH. Only sometimes. More often I get 6, as if it's registering both the partial and full stalk movement as separate events. This happens no matter what speed I try to move the stalk at.

Anybody else?

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Yep, I've seen this too from the very beginning. Should be easily fixable in software, although the software development pace has felt slow as molasses so...

Ditto, needs to be fixed

Puyallup Bill said:

Oh how I wish I could have the old fashioned "one click up, one click down" arrangement.

While we are at it, please give me another old fashioned setting - allow ME to set the windshield wiper intermittent setting, not some rain sensor thingy.

Click to expand...

Luddite :tongue:

Hoho I think I've solved the problem! Or rather, there wasn't any problem in the first place!

We all know the cruise control stalk comes from mercedes. Here's a page of a mercedes owner's manual regarding their cruise control:


IMPORTANT POINTS TO NOTICE:
The manual shows that the partial indent changes the speed by 1mph (1km/h) BUT IN REALITY, 1km/h is equal to 0.621371 mph.
Secondly, it claims to change the speed by 5mph (10km/h) for each full deflection BUT IN REALITY, 10km/h is equal to 6.21371 mph.

If you haven't already figured out the "problem", I just did an experiment that will prove that the "problem" doesn't exist.

Over here in my local area, we use the metric system just like every other country I've been to except for the USA.
I took my Dad's mercedes out and I'm used to the cruise control on this ML-class Mercedes.
Every partial push = 1km/h, and each full push = 10km/h change.

There has never been any intermittent behavious with the numbers on this car but here's the interesting thing - I can select METRIC or IMPERIAL units from the car settings.
I went ahead and changed the setting to IMPERIAL and although my analog display still showed km/h, the digital speed display started displaying in imperial units.
I took the car up on to the expressway (highway in american) and engaged, disengaged, and adjusted the cruise control several times.

HERE COMES THE REVELATION:
After having driven the car for more than 2 years with a consistent cruise control that always gave me 1km/h or 10km/h changes, now full pushes of the stalk sometimes gives me 5mph and sometimes gives me 6 miles per hour in change of speed according to the digital speedometer.

If you haven't already figured it out - it seems that daimler-designed cruise control is based on the metric system and NOT the imperial system.

The screenshot above of the MB owners manual is the ONLY version that shows "5 mph (10km/h)". If you pull up the same owners manual from Mercedes UK, or any other metric-based country, it simply says "10km/h". There is no mph in brackets or anything.
In simple english, it means that the car will APPROXIMATELY change the speed by 5mph (but in reality it's 10km/h)

And depending on the current speed and changed speed in km/h, the display mph has to be rounded up or rounded down to a whole number. Example if the result is 62.3 mph you will see 62. If the result is 62.6 mph you will see 63. So sometimes you end up seeing 1 more or less than you think you ought to see.

Lastly, I don't know how the metric version of the Tesla Model S works (dont have one yet) but if that is not doing 1 / 10 accurately, it may look like Tesla engineers designed the car around the imperial system, converted daimler's metric data to imperial to work with the rest of the imperial sensors and stuff and when someone selects metric units, the car then takes the imperial data and converts it to metric again (double conversion). If any rounding is done in the middle, there might be a discrepancy.

Of course, this is all speculation based on daimler/mercedes and may have NOTHING to do with Tesla... It could just be a daimler hardware part with 100% tesla software and codes so I could be wrong...

scaesare said:

Pushing the stalk fully up/down should change by 5MPH. Only sometimes. More often I get 6, as if it's registering both the partial and full stalk movement as separate events. This happens no matter what speed I try to move the stalk at.

Click to expand...

I've noticed this too. I've found that if I very quickly push up/down all the way, I do get just the 5MPH change.

As an aside, I wish they actually displayed the set cruise control speed, so we wouldn't need to guess at it. Like this:

Doug_G said:

Personally, I'd like to see 1 kph / 5 kph when you have the displays set to metric. Feature is borderline useless as it stands.

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+1000

I guess it would be nice to have this work more precisely, but my bigger beef with CC is the way the car actually makes the speed change. When you increase the speed by the large amount (let's say approx 5mph :smile, the car increases the speed very smoothly. But when you make the small increase, the car seems to abruptly jump to the higher speed. Decreasing the speed seems to be fine, but I just think it could be a little less aggressive going up to that next mph. Anyone else agree?

JohnEC said:

I guess it would be nice to have this work more precisely, but my bigger beef with CC is the way the car actually makes the speed change. When you increase the speed by the large amount (let's say approx 5mph :smile, the car increases the speed very smoothly. But when you make the small increase, the car seems to abruptly jump to the higher speed. Decreasing the speed seems to be fine, but I just think it could be a little less aggressive going up to that next mph. Anyone else agree?

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+1 Completely agree

JohnEC said:

I guess it would be nice to have this work more precisely, but my bigger beef with CC is the way the car actually makes the speed change. When you increase the speed by the large amount (let's say approx 5mph :smile, the car increases the speed very smoothly. But when you make the small increase, the car seems to abruptly jump to the higher speed. Decreasing the speed seems to be fine, but I just think it could be a little less aggressive going up to that next mph. Anyone else agree?

Click to expand...

I find that this is also a problem from the imperial/metric situation.

When in metric, the mercedes smoothly accelerates 1km/h. In imperial, it seems to lurch forward. This appears to be because it has to accelerate MORE than designed. (1 mph = 1.60934 km/h, so about 60% more minimum acceleration)

- - - Updated - - -

scaesare said:

I also agree that the small speed increases seem a tad abrupt.

I also am confused by some behavior... occasionally when CC is set (say 55MPH), but it's not active at that speed (I had to hit the brakes, and I'm now at 40), when I push all the way down, instead of resetting to my current speed, it ratchets the set point down by the 5MPH increment, rather than setting to my "current" speed.

It's not consistent though, so I'm not sure if I'm doing something differently on some occasion.

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When CC is temporarily cancelled but not yet disabled, it is designed to store the previous set speed in temporary memory if you wish to recall it later (to which it will accelerate back to the memorized speed). If you DO NOT recall the speed, and you attempt to flick the stalk up / down, it is designed the modify the speed in the memory. When you eventually choose to recall the memorized speed, it will include any modifications you made while it was in memory.

Again, this is based on Mercedes as I'm still waiting on RHD Tesla production. If anyone wants to FedEx their Tesla to me for a proper experiment I'll be more than happy LOL.

araxara said:

I've noticed this too. I've found that if I very quickly push up/down all the way, I do get just the 5MPH change.

As an aside, I wish they actually displayed the set cruise control speed, so we wouldn't need to guess at it. Like this:
View attachment 23924

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Nice.

Also be better if cruise colors were white instead of blue.

Anyone else think this makes it harder to "see" that high beams are on?

Doug_G said:

Personally, I'd like to see 1 kph / 5 kph when you have the displays set to metric. Feature is borderline useless as it stands.

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It must have been a software update since a year ago, but I use the +/-5 kph every day (I miss my adaptive cruise for my 407 run to work every morning, dial in 120km and forget it), so now I drive using the cruise. Note that holding the stalk down slows the car down smoother than disengaging the cruise, not just one foot driving, zero foot driving.

The trick in slowing down is not to use the stalk but to disengage cruise while pushing on the accelerator pedal slightly. That avoids the jarring from going from cruise to regen. More on that here:
Cruising in the Tesla Model S | Tesla Living