Poor efficiency on R1S?

[Cycliste]

I'm averaging around 3 km/kW (20" AT tires) But I just discovered the efficiency display for the driver. I can get my efficiency around 3.8 km/kW by being very smooth and gentle on starting from stops and when cruising. I am basically learning how to drive again.

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[Atlrivian]

For those comparing R1T to R1S remember the R1S has more cabin space to cool than the R1T so it has to run harder to cool down that space. I have 21" wheels and find I'll be below 2 mi/kwh at the start then after 5-10 minutes of driving I'll be up above that no matter highway or city unless the vehicle is really hot (haven't tested in cold).

I can't speak to the efficiency of the A/C unit but I think it works pretty well except maybe the noise.

This makes a lot of sense to me. My wife's R1S is always hotter than my R1T and takes forever to cool.

 

[Zoidz]

How do you know there is logic involved in the AC system? The system tear down and review I watched (Munro) indicated the AC system was a simple one like used in an ICE vehicle (not saying this is correct ?). Also, assuming the AC system has a complex, intentional design, it seems very unlikely that turning it on and off to make some component shut down would actually make it work better (and if it does that this is an advisable long term use). Otherwise, why wouldn’t that just be how the system operates? Thanks!

I recall watching a Munrow video that discussed various routing valves, etc. as part of the cooling system...? I believe it was a young lady and a guy doing the video.

Regarding turning it on and off, numerous people have posted that when the compressor is running fast when you first get in the vehicle, cycling it off and on makes the compressor run slower but continue to cool the vehicle. I too have tried it and it does work this way. We are not making it up, lol. It it were a "simple" system, it would not respond this way.

Have you ever had a problem with a computer or phone where rebooting it solved weird problems? Rivian is a computer on wheels.

Finally, as I posted in another thread, Rivian says there is control logic for cooling system:

The Rivian EPA document date 5/26/23 says there are "solar load sensors" as part of the cooling system logic..... ?

08.06.03 Climate control system logic
HVAC software has multiple modes which can be selected based on user preference:
• In Manual Mode, the user has complete control on blower speed, temperature, and airflow
distribution to face or feet. Recirculation of air is also manually controlled by the user.
• In Auto mode, the software provides adequate heating and cooling requests to control the
breathing temperature of both driver and passenger to the requested setpoint. In this mode, the
airflow distribution and the blower speeds are automatically selected to maintain the desired
temperature from the screen. The software estimates the breathing temperature of individual
passenger based on airflow through ducts, In-Cabin sensors, external ambient temperature
sensors, and solar load sensors. Recirculation of air inside the cabin is automatically selected
based on humidity level inside the cabin.
• Additionally, defrost or demist mode is provided to the user for a clear view while driving.
During defog mode, the software supplies conditioned air towards the windshield based on the
dew point calculation. If the desired mode is Defrost, the PTC (Positive Temperature
Coefficient) heater blows hot air towards the windshield to clear frost

 

[rpmtexas]

I recall watching a Munrow video that discussed various routing valves, etc. as part of the cooling system...? I believe it was a young lady and a guy doing the video.

Regarding turning it on and off, numerous people have posted that when the compressor is running fast when you first get in the vehicle, cycling it off and on makes the compressor run slower but continue to cool the vehicle. I too have tried it and it does work this way. We are not making it up, lol. It it were a "simple" system, it would not respond this way.

Have you ever had a problem with a computer or phone where rebooting it solved weird problems? Rivian is a computer on wheels.

Finally, as I posted in another thread, Rivian says there is control logic for cooling system:

The Rivian EPA document date 5/26/23 says there are "solar load sensors" as part of the cooling system logic..... ?

08.06.03 Climate control system logic
HVAC software has multiple modes which can be selected based on user preference:
• In Manual Mode, the user has complete control on blower speed, temperature, and airflow
distribution to face or feet. Recirculation of air is also manually controlled by the user.
• In Auto mode, the software provides adequate heating and cooling requests to control the
breathing temperature of both driver and passenger to the requested setpoint. In this mode, the
airflow distribution and the blower speeds are automatically selected to maintain the desired
temperature from the screen. The software estimates the breathing temperature of individual
passenger based on airflow through ducts, In-Cabin sensors, external ambient temperature
sensors, and solar load sensors. Recirculation of air inside the cabin is automatically selected
based on humidity level inside the cabin.
• Additionally, defrost or demist mode is provided to the user for a clear view while driving.
During defog mode, the software supplies conditioned air towards the windshield based on the
dew point calculation. If the desired mode is Defrost, the PTC (Positive Temperature
Coefficient) heater blows hot air towards the windshield to clear frost

Sorry, I get all that and am familiar with those aspects of the system. I was speaking of the actual hardware in the vehicle that handles the cooling. Also, my point about turning it on and off every time to make it work better is contrary to the idea that it is a complex, finely tuned computerized system. I have not heard anyone say that there is a problem with the compressor that is solved by a reboot. Seems like I have seen Rivian saying the opposite, so again, my point still stands.

 

[Zoidz]

Sorry, I get all that and am familiar with those aspects of the system. I was speaking of the actual hardware in the vehicle that handles the cooling. Also, my point about turning it on and off every time to make it work better is contrary to the idea that it is a complex, finely tuned computerized system. I have not heard anyone say that there is a problem with the compressor that is solved by a reboot. Seems like I have seen Rivian saying the opposite, so again, my point still stands.

Again, read the multiple posts here saying that after turning off and on the cooling system, it resulted in the compressor running at a slower speed. It's reported by many people. You can choose to believe otherwise if you want.

I have not heard anyone say a reboot solved the compressor problem either. Read again, I didn't say that at all. I made an analogy to a computer system. This is a system that the compressor is one part of many. The system acts like the control routine has a specific operating mode with startup parameters that are loaded when the vehicle state is unoccupied and the doors are unlock/opened. Powering off and on manually via the display appears to put the system in a different operating mode and load a diferent set of operational parameters. That's proven by multiple user reports. That is consistent with a computerized system that is complex and poorly tuned. With all the reports of problems and Rivian making firmware changes in the previous revision, it's clear that this is not a "finely tuned system" as you called it - it's a work in progress.

 

[Whale Blubber]

As another data point, I took my first somewhat lengthy trip tonight. I did ATX-Houston (The Woodlands), about 160 miles, and managed 2.45 mi/kwh, on 22" wheels and AC going the whole way. This was in the evening, so only about 90F with no strong sunlight. I did the whole thing in conserve mode, and spent about 25 minutes sitting unmoving in a drive-through line at Whataburger, which likely messed with the speed average. Anyway, I ordinarily drive only fairly short trips around the city, 10-20 miles max, in AP mode and 100-105+ degree heat, where my average efficiency is usually about 1.8 total, so I was pretty excited to get it to exceed 2.4. Arrived with 160 miles left in the battery on conserve mode, so that rounds out to just about 320 total for the 22" wheels.

 

[Epicloop]

Currently on my trip meter I achieved 3.88km/kw (2.41m/kw) This is with R1S quad on 20" AT with a 500km (310mile) return trip in conserve over a mtn pass (10,000 ft total gain/loss) and some local driving that involves a 850' climb/descent every time I leave home, 10% of the time was towing a very small cargo trailer.This was generally not going more than 5% over speed limit.
That puts me at 310-325miles (129 /135kwh) which is way over EPA so pretty satisfied with that.

 

[Craigins]

Also, my point about turning it on and off every time to make it work better is contrary to the idea that it is a complex, finely tuned computerized system. I have not heard anyone say that there is a problem with the compressor that is solved by a reboot. Seems like I have seen Rivian saying the opposite, so again, my point still stands.

Hi, I'm the one that posted to power cycle the AC

It is not contrary to the idea that the ac is complex, it actually supports it. As a software engineer, my take is their code checks for certain conditions and then sets a Max AC toggle. However the conditions check is not executed again for a long period of time, wasting energy by being stuck in Max AC mode. Toggling the AC would then forces this recheck and allows the AC to operate normally.

This tracks with other Rivian software systems. I'd rate their programmers at about average and their program leads at below average. Many issues I've seen with the Rivian can be caused by poor soft requirements during the development phase.

 

[rpmtexas]

Hi, I'm the one that posted to power cycle the AC

It is not contrary to the idea that the ac is complex, it actually supports it. As a software engineer, my take is their code checks for certain conditions and then sets a Max AC toggle. However the conditions check is not executed again for a long period of time, wasting energy by being stuck in Max AC mode. Toggling the AC would then forces this recheck and allows the AC to operate normally.

This tracks with other Rivian software systems. I'd rate their programmers at about average and their program leads at below average. Many issues I've seen with the Rivian can be caused by poor soft requirements during the development phase.

That wasn’t exactly what I was saying. This is the problem with internet conversations. Talking past each other. ?. In any event, turning the AC on and off strikes me as an odd way of making it work better. If it is a complex system reading lots of variables and turning on and tuning the system components based off those variables, the user stepping in and cycling the system off and on to force a shut down / power reduction of one component of that system doesn’t make sense. Basically it’s the user saying, I know this is what you think is the best setting computer, but I disagree so I am going to force you to turn off/down the compressor. I get the point about a recheck, assuming that is how it works. But again, to me, it seems less likely that this complex system just needs to recheck its variables again and more likely that people are running into faulty components, low refrigerant, an undersized AC system, or an AC system that gets compromised by battery cooling needs in high heat. But hey, if unplugging it and plugging it back in is working for people, cycle on!

 

[Craigins]

I get the point about a recheck, assuming that is how it works. But again, to me, it seems less likely that this complex system just needs to recheck its variables again

I'm not sure how closely you've followed the release of the R1 platform.

We've already seen multiple instances of this improper coding. The few instances I've seen so far:

1. Charging Threshold. If you set the threshold to 70%, originally the vehicle would charge exactly to 70%, then turn off charging. When the charge dropped to 69.9% the vehicle would start charging again. This essentially kept the vehicle awake almost 100% of the time.
2. Driver+ follow distance. The distances are set by those little lines. Similar to the charging point, if you were closer than the line, the vehicle would immediately apply the breaks, then have to speed up after it fell behind the line.
3. Also driver+, lane centering. The vehicle was programmed to drive in the exact center of the lane. This led to the vehicle constantly zigzagging as it attempted to stay exactly centered.

It is entirely feasible that someone wrote a software spec for the AC:

"If the BMS requires cooling and the cabin calls for cooling, enter in Max AC mode."

Then the software engineer programmed that. However the spec never said "After the BMS enters optimal temperature range, drop out of Max AC mode."

This style of software error has been Rivian's MO since release.

 

[RivianNowPlz]

Small sample size in 48 hours of freeway driving and hard acceleration.

 

[R1TS]

I'm averaging around 3 km/kW (20" AT tires) But I just discovered the efficiency display for the driver. I can get my efficiency around 3.8 km/kW by being very smooth and gentle on starting from stops and when cruising. I am basically learning how to drive again.

Almost read it as 3mi/kWh and was about to scream at my Rivian. Then I realized you wrote km.

 

[Warren]

I'm in inland No Cal (Sacromento area) blasting the AC and never have cycled AC on/off (but now sure will, Thanks for this gem). I hardly ever apply the brakes on the back roads here as a costing stop usually works. Using $.40 KW as an average price (peak here is $.50!) this makes the cost of power around 5.7 cents per mile. Comparing to a 50 MPG Hybrid the cost for fifty miles would be $2.85 vs about $5.00 for gas here. Yes my KW cost cited here is high and likely is lower making for better MPG yield. The Rivian software rounds down so actual SR1 cost per mile is a bit less.

For powering the 3.5 ton beast to me this is more than Aok. My quad SR1 is in All-Purpose mode all the time w/21" road tires. The aero covers are off but for those of you caring about this stuff that matters and I wonder of these reports how many are using the aero covers? My 3367 miles would be around 3485 using a multiple of 1.035. I turn off cooling/heating system when parked and lock at home to avoid waking up every time I pass by many times a day that saves on some battery drain.

 

[rpmtexas]

Pretend I’m a giant baby and explain. Is the “range” left just a function of the percentage of the charge remaining multiplied by the theoretical max range? And then my driving “range impact” has positive or negative effect? Or is the “range” left calculated based on battery charge and some average usage calculated from my past driving? I’m asking because today I drove 26 miles and the range only went down 8 miles. But it was highway driving not my normal around town stuff.

 

[sub]

Pretend I’m a giant baby and explain. Is the “range” left just a function of the percentage of the charge remaining multiplied by the theoretical max range? And then my driving “range impact” has positive or negative effect? Or is the “range” left calculated based on battery charge and some average usage calculated from my past driving? I’m asking because today I drove 26 miles and the range only went down 8 miles. But it was highway driving not my normal around town stuff.

The user manual says that it is B. It should be looking at recent history and using that to guess how efficiently you will drive in the future. There is even a button to wipe that history.

However, personally I have not seen any evidence that it is actually doing this. My gauge has always shown the exact same number for range at any given %, assuming the drive mode is the same.

What does clearly change the range gauge is the drive mode. If you change the drive mode it instantly updates the range shown on the dash.

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