Efficiency Has TANKED

[Jayhawkeye]

Warmed the cabin for 10 minutes this morning inside my garage, which was at 56 degrees. Had the fan at 70 degrees on the lowest setting, quick jaunt down the road (5-6 miles) on a sunny 45 degree day.

look at that bunny slope!

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[izgoy]

Model S has a heat pump, but it doesn't matter much below 40-45 degrees as heat pumps aren't that efficient at really cold temps

This is not the case with modern heat pumps. This was the case with heat pumps 20 years ago. Modem heat pumps are effective down to -4 F (-20C).

 

[izgoy]

They should have shipped this car with a heat pump. Many adventures involve cold weather.

Absolutely the case.

 

[goldburger]

That drop off on the end of the graph is the heater kicking on— I keep it in 72 or 73 auto and it changes wether heat or AC on its own. The efficiency stayed around 1 the rest of the 20 min drive home. LA is not cold… my truck has been wildly underperforming in the efficiency department since day 1.

I had a loaner on OE 20’s that I drive 2k miles over 4 weeks and rarely got below the 2 line and it also never moved as fast as mine does— much more stead and smaller changes in efficiency rate. Overall I did about 2.2 over 2k miles vs 2.1 over 12k miles in my OE 21’s and 1.9 on my 20’s with 33” Recon Grapplers. Changing wheels and tires has basically made it impossible for rivian to want to consider any issue, even the issues that predate the wheel and tire swap.

 

[jeeden]

This is not the case with modern heat pumps. This was the case with heat pumps 20 years ago. Modem heat pumps are effective down to -4 F (-20C).

The will go even lower than that now. Maine and a lot of New England are seeing a wholesale replacement of heating systems to electric heat pumps and they are even popping up in Alaska now. They are able to extract heat well below zero (almost 20 below F). With the heat pump split systems, the hot air is directly injected into the rooms (like a vehicle) instead of going through ducting and cooling off on the way to the room.

NY is changing all of it's subsidized housing from steam radiators to these interesting window heat pumps that don't block the windows, don't burn you, work for heat and AC, etc.

 

[sfvR1S]

I've had 3 EV's & 1 PHEV prior to the R1S and even in L.A., where it doesn't get too cold, I've noticed decrease in range from all 3 EV's during winter months.

 

[NineElectrics]

Changing wheels and tires has basically made it impossible for rivian to want to consider any issue, even the issues that predate the wheel and tire swap.

It is illegal for Rivian to invalidate your warranty because you changed wheels. But they have a monopoly on service, so they can do what they want with impunity, sadly…

 

[RivAW]

Just drove back home from a night out and was triggered by the efficiency changes the last 7-10 days, so I closely monitored on a 30 minute drive at 70 mph with no wind whatsoever.

heat at 75, 2 dots for 25 minutes
Heated steering for 10
Temp was 43 degrees
Hardly any elevation change
Last mile was in my hood at 25 mph max.

it’s been this way for one week, out of nowhere, after hovering 2.1ish daily.

First EV? This is what happens when it gets cold. The biggest efficiency killers for your EV are cold (and using the HVAC for heat), speed, tire pressure and driving habits (acceleration)…

 

[goldburger]

It is illegal for Rivian to invalidate your warranty because you changed wheels. But they have a monopoly on service, so they can do what they want with impunity, sadly…

I mean they already hedge on efficiency issues by saying they don’t know my driving style, etc.

 

[HyperionMark]

This is not the case with modern heat pumps. This was the case with heat pumps 20 years ago. Modem heat pumps are effective down to -4 F (-20C).

I know it's not the norm, but we have a heat pump (mini split) in our house that is rated to produce heat down to -15F. But thank you for setting the record straight on modern heat pumps. So much better than they used to be and most sold can produce some heat in pretty cold temps.

 

[Gixxer]

Hmm I'll have to post my results for my R1T. Live in Georgia and my truck is parked outside normally plug in every 2 days. Temps have taken a hit in my effiency about 5-10% drop due to colder morning around the mid 30s highs in the 50s. Around 40 miles to work and 40 back home. 22 inch wheels normally charge to 80% now to 85 due to temp and 5 min warmup to 75 in the morning seats and steering wheel. I turn in down once I'm rolling to around 73'. Definitely noticed the hit on a 400 mile road trip holiday weekend one way. Normally charge half way to 85% both ways. Arrived back home with 14% where as I do have a Rivian home charger. Always testing and comparing EV Life. Perfect not so much but fun. YES

 

[Wayne]

Round up to factor in 25°F wind chill .

Wind chill only affects animate objects as it speeds evaporation from skin. Yes, the wind may drive the ambient temperature through opening can push the ambient temp in, but it won't include a wind chill factor. At least that's my understanding.

 

[goldburger]

What is the optimal temp of the battery?

 

[Riviot]

Wind chill only affects animate objects as it speeds evaporation from skin. Yes, the wind may drive the ambient temperature through opening can push the ambient temp in, but it won't include a wind chill factor. At least that's my understanding.

Wet bulb/dry bulb affects. More wind at the same temp wicks electrons (heat) away quicker. Same way a ship in the water gets colder when it goes faster.

 

[waitingonanr1s]

I'm noticing the loss in efficiency too - while not surprised, I don't think I expected to lose 20-25%. Not a huge deal, but more material than I thought.

This has me pondering my trip from CO to NC for the Holidays. I normally go the quickest route (I-70) unless there's a storm, then I would take I-40 instead. It sounds like it may be beneficial from an energy perspective to consider I-40 if the temperature differences are large.

Of course, I guess since you're hopping constantly between L3 chargers, then the impact of the cold wouldn't be as great?

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