SR+ vs LR for long commuting

[Tippytj2]

New member here and new to EVs. I’ve currently got a M3 SR+ on order for deliver Nov 18-Dec 31. I’m on the market because I took a new job that will require regular commuting (12 x mo) about 70mi each way and I want a comfortable EV with adequate range and good driver-aid software - the M3 seemed the best fit. I’m open to other manufacturers, but am really curious to see how FSD develops and think tesla is still ahead of the EV curve generally. My priority is having a safe EV that I don’t mind spending lots of time in. I have 3 small kids (other vehicle AWD minivan) and live in the mountains of NC, so some winter (snows a handful of times per year, routinely in 20s-30s Dec-Feb) but generally pretty mild winters. The commute is down a mountain mostly on divided highways, but the second half is rural highway without limited access and some traffic lights, last bit is more urban. Probably at least 2000ft elevation drop there (and then rise on the way back). So, this is the need - 140mi single charge daily, pretty significant elevation change, able to handle cold winter temps occasionally, ideally ok in light snow in a pinch, but generally mild weather and longevity to do this for over 20k mi per year indefinitely (or until I want a new car - I usually get boarded every 3-5yrs).

I’m struggling deciding between my existing SR+ LFP order vs changing to new LR or going rogue and getting 2021/2022 used LR w/ FSD (not going to pay $12k out for the gate, but will probably try it out via subscription and see what it adds over autopilot). My biggest fear with SR+ is I’m on my way home and the BMS screwed up and I don’t have enough juice to get home. It doesn’t seem clear to me based on this thread Model 3 SR+ LFP Battery Range, Degradation, etc Discussion
If LFP should actually be charged to 100% daily, or if 70% is still better for longevity with weekly 100% for range estimation - keep in mind I’ll put 20-30k mi on the car per year, so longevity and maintaining range is important! Cold weather performance of LFP and weight going up elevation is also a concern to me. Generally I am more attracted to the lower price and greater safety of the LFP battery, and don’t care too much going 0-60 in 5.7sec or 4.1 or whatever (both way faster than any other vehicle I’ve ever owned), though AWD would be a nice perk if unannounced snow decided to show up going over the pass and the added performance would be a novelty. Mostly, I’m willing to shell out for the LR, but I want to feel confident either the SR+ or LR will get me through this commute without range anxiety coming home and in outlier conditions (cold borderline road conditions), though I could take the minivan if it looks iffy (I’m a physician, so working from home not an option). When I run the numbers LR 70/80% - 10/20% it seems this should be plenty of range for the commute, even if taking into account cold, range decay and elevation, but range loss once I’m pushing 100k mi in a few years is a bit of a concern. Now I’m not sure the same can be said for LFP, though I have the option of 100% charge, esp in winter, which would seem to more than offset routine charging to 70-80% in LR.

Am I over thinking it? Will I make it fine in either vehicle? I have to say, I’m attracted by the LR so I can keep my charging habits consistent and don’t have to worry if I’m screwing things up constantly charging LFP to 100% or trying to only do it on certain days. I’m also waiting to see about these tax rebates, in which case if Tesla lowers the price of the LR to qualify, it seems like a no brainer, but I’m trying not to rely on the government or tesla for my decision, and I’m not sure I or the vehicle will ultimately qualify anyway.

Thoughts? Should I just go LR, have a nicer AWD vehicle and be anal about charging to maximize longevity, or go LFP (perfectly adequate vehicle for me), save 10 grand up front, drive the minivan when the weather looks to be iffy, charge to 100% and forget it?

 

[AlanSubie4Life]

You’d be getting the 60kWh RWD now, right? (~57kWh usable if the buffer is not out of whack.)

Anyway even at 300Wh/mi, 140 miles is just 42kWh. And from your description you’ll do way better than that most of the time. (People seem to report values for non-freeway driving in the low 200s for the RWD vehicles. Your described commute seems ideal for quite low consumption. Average speed something like 45mph?)

In a blizzard you might have problems I guess. But that would be so far outside the norm it could be a problem for the LR too (getting stuck for 10 hours or whatever). Just don’t get stuck.

If you put decent all weather tires on it, you can also drive it year round.

Either way this is a lot of miles to put on the battery, but the LFPs seem to be holding up just fine, if not better than the NCAs.

Budget for 20% capacity loss. Even in that case, you’ll be fine, using ~70% of the capacity on the 140-mile round trip. Plenty of margin for using features, etc.

 

[Rocky_H]

Am I over thinking it? Will I make it fine in either vehicle?

Yes. The range doesn't sound like a problem either way, especially with as mild as those Winter conditions are. I would probably just base it on if you think you need all wheel drive or not.

 

[Tippytj2]

Yeah, I kindof like getting in the weeds with tech and have a tendency to over think, so I appreciate you knocking sense. I’ve also never owned an EV, so it all makes me a little nervous.

While I agree on its face it seems either vehicle should have plenty of range (SR+ charged to 100% or 273mi rated range and LR 80-10% rated range ~250mi should both cover 140mi without issue), but when you crunch the numbers of battery degradation up to 70% within first 100-120k mi (3-5yrs of ownership for me) and winter range decline of 20-40% at temps in the 20s (which I will see), plus elevation change (which I haven’t really read much about in terms of effect on range, other than not good), 250-270mi rated range seems like it could easily decay to 120-130mi of range, which doesn’t cut it for me. Sure, this is worst case scenario and I can precondition and other things to mitigate winter range loss, I just want to make sure I don’t buy a vehicle I regret in a couple years. These calculations also make me nervous buying any EV with less than 300mi rated range for my needs (LFP 100% charging not withstanding, but based on my read the verdict is still out if this is truly a good idea for battery life and thus long-term retained range).

Does everyone really think it’ll be a non-issue?

 

[AlanSubie4Life]

plus elevation change (which I haven’t really read much about in terms of effect on range, other than not good)

It’s a round trip so it won’t matter much, especially if you don’t regen much on the way down (regen is desirable but inefficient, but using less energy to move forward because you are going downhill somewhat but not too steeply is good). You can just use PE = mgh to calculate the numbers but it is something like 8-10 miles of range, 1.6kWh, per 1000 feet (also depends on the vehicle model of course, not just because of the weight, but also due to energy content of the rated miles changing).

but when you crunch the numbers of battery degradation up to 70% within first 100-120k mi (3-5yrs of ownership for me)

I think it’s unlikely you’ll see less than 80% of your initial capacity in that time period, though for LFP we know less.

You start at 60kWh, so taking that down to 48kWh (45kWh usable), you can still squeak by with 320Wh/mi usage (I think it is unlikely that you’ll see this; plenty of reports of closer to 200Wh/mi-230Wh/mi at modest speeds).

The winter range hit (or in rain) can be significant but given the heat pump and given the underlying efficiency of the RWD I think you’ll do pretty well.

What’s the average speed on the route? Takes you about 1.5 hours? Or more?

 

[AlanSubie4Life]

Also, plug your route and vehicle into ABRP (both ways, because the elevation matters!), and get an estimate. They have a table which allows you to get kWh usage - but there are also a lot of options so be sure to set it all exactly correctly and that it is properly estimating your average speed.

Not knowing that much about the route, I think you’ll find it estimates you’ll use 30kWh or so round trip. 11-12kWh there (170Wh/mi), about 18-19kWh (260Wh/mi) on the way back.

Hopefully the trip to work doesn’t start with actual required regen since that would actually be non-optimal, since it could require use of brakes instead (though LFP does allow some regen near 100% apparently). This would require a significant hill right after starting out, to be non-optimal, which is unlikely but possible per your description.

 

[Rocky_H]

but when you crunch the numbers of battery degradation up to 70% within first 100-120k mi (3-5yrs of ownership for me) [...] Sure, this is worst case scenario

I think you are imagining pretty far beyond worst case here. You won't get near losing 30% within 5 years and 120K miles.

 

[Tippytj2]

Thanks for your thoughts.

60-70mph most of the way, 45mph last ~10mi, anticipate some stop and go, so shouldn’t be terrible for EV range based on avg speed (~60mph). There is also a supercharger 10-15mi from my house on the way, but def don’t want to rely on that.

I think the LFP SR+ is the best option for me when considering high mileage commuting is my need. I’m not super stoked paying almost $60 grand for the LR, I can still get FSD on the SR+ if I like it, and the need for AWD will be pretty edge case plus I have the van for backup if weather looks terrible.

My only hesitation is I am just not convinced that actually charging the LFP to 100% daily is a good idea for battery durability, despite what Tesla says (they just want battery to last to 100k mi and 70% original charge, then have you buy another car or another battery). Yes, LFPs appear to have 3-5x the cycle life of NCA/NMC in the laboratory, but I have not actually seen real-world data for LFP powered autos (though it seems this should exist in China where they’ve been common-place for 10yrs). Real word loads, charge-rates, DoD, temperature fluctuations, humidity, etc, could all impact durability, not just cycles, so I’d say the verdict is still out until there are a bunch of M3s with LFPs running around with 200-300k miles on them (I guess I’ll be a part of that experiment). The prudent thing to do seems to charge to 70% daily, and 100% every week or two to calibrate the BMS. I’m just a little worried 70% of 273 won’t actually get me to work and back in some conditions, which may be hard to predict. I should probably just forget about it though, and charge to 100% routinely in the winter and weekly otherwise, because this will probably be fine and I’ll get bored/want a new car in 3-5yrs and 100k mi anyway.

 

[AlanSubie4Life]

60-70mph most of the way, 45mph last ~10mi, anticipate some stop and go, so shouldn’t be terrible for EV range based on avg speed (~60mph).

So it takes an hour and 10 minutes to get to work. Anyway you can plug into ABRP and adjust the speed to match, but the number of kWh used may be slightly higher than what I quoted above.

My only hesitation is I am just not convinced that actually charging the LFP to 100% daily is a good idea for battery durability, despite what Tesla says

It’s not the best probably but it likely doesn’t matter very much especially if you’re usually pushing it the most in cold weather.

But anyway you will basically never need to charge to 100% (except for the BMS) I would guess (for this trip, barring any special additional side trips). The RWD (there is no SR+) just has so much capacity and is so efficient it is going to be a nonissue except possibly in the absolute worst conditions.

 

[Tippytj2]

Yeah, I think you’re right. I’m really just looking for someone to make an argument to get the cooler/faster LR…and I’m a little freaked out the BMS will screw up when I’m coming up the mountain thinking I charged to 70% before I left, when in actuality I charged to 50% and I don’t have enough range to get home.

Are people actually experiencing poor performance of range estimates in LFP-equipped M3s when they don’t charge to 100%, or is this more a theoretical problem in practice/does Tesla have it figured out?

Thanks for your thoughts.

60-70mph most of the way, 45mph last ~10mi, anticipate some stop and go, so shouldn’t be terrible for EV range based on avg speed (~60mph). There is also a supercharger 10-15mi from my house on the way, but def don’t want to rely on that.

I think the LFP SR+ is the best option for me when considering high mileage commuting is my need. I’m not super stoked paying almost $60 grand for the LR, I can still get FSD on the SR+ if I like it, and the need for AWD will be pretty edge case plus I have the van for backup if weather looks terrible.

My only hesitation is I am just not convinced that actually charging the LFP to 100% daily is a good idea for battery durability, despite what Tesla says (they just want battery to last to 100k mi and 70% original charge, then have you buy another car or another battery). Yes, LFPs appear to have 3-5x the cycle life of NCA/NMC in the laboratory, but I have not actually seen real-world data for LFP powered autos (though it seems this should exist in China where they’ve been common-place for 10yrs). Real word loads, charge-rates, DoD, temperature fluctuations, humidity, etc, could all impact durability, not just cycles, so I’d say the verdict is still out until there are a bunch of M3s with LFPs running around with 200-300k miles on them (I guess I’ll be a part of that experiment). The prudent thing to do seems to charge to 70% daily, and 100% every week or two to calibrate the BMS. I’m just a little worried 70% of 273 won’t actually get me to work and back in some conditions, which may be hard to predict. I should probably just forget about it though, and charge to 100% routinely in the winter and weekly otherwise, because this will probably be fine and I’ll get bored/want a new car in 3-5yrs and 100k mi anyway.

 

[AlanSubie4Life]

Are people actually experiencing poor performance of range estimates in LFP-equipped M3s when they don’t charge to 100%, or is this more a theoretical problem in practice/does Tesla have it figured out?

Apparently, yes. It’ll probably get better with future updates, but apparently it’s known the buffer can expand to 11% of the capacity of the battery if the car decides it isn’t sure what it has.

I would just charge to 100% weekly or something approximating what Tesla says, and not worry about it though.

You’ll have enough margin this shouldn’t matter if you charge to 80-90% though. Maybe charge to 100% even more often since you’ll be putting so many miles on it. Don’t want it to lose track.

I wouldn’t do 70% in your case because what if you want to do other driving that day? Just keep it convenient for yourself and don’t worry about the battery.

 

[Big Earl]

Where's work? Is there a Supercharger (Old Fort) or CCS station (Biltmore Park) on the way for those worst-case scenarios?

While it's doable in most weather conditions, you might find the SR+ to induce some range anxiety in cold weather, particularly with snow. If you don't have intermediate charging options, the long range will provide you with significant extra buffer to cover cold weather or unexpected side trips and detours. Plus, the long range is way faster.

 

[RoBoRaT]

Yeah, I think you’re right. I’m really just looking for someone to make an argument to get the cooler/faster LR…and I’m a little freaked out the BMS will screw up when I’m coming up the mountain thinking I charged to 70% before I left, when in actuality I charged to 50% and I don’t have enough range to get home.

Are people actually experiencing poor performance of range estimates in LFP-equipped M3s when they don’t charge to 100%, or is this more a theoretical problem in practice/does Tesla have it figured out?

I'd get the LR if I were to do it again.

I commute 80 miles one way in SoCal weather mostly on AP in freeway 70-80 mph, and logged 105K miles on a 2018 LR Model 3 in 2 years time.

The 2018 LR had lost about 12% in the 2 years I run that route, last check was 270 miles at 100% SoC (310 new). The efficiency was about 80%, I burn about 200 EPA rated miles (for the 160 mile commute) daily. I charge using Wall Connector to 90% everyday. By 105K miles I have about 245 EPA rated miles at 90% SoC.

 

[Rocky_H]

My biggest fear with SR+ is I’m on my way home and the BMS screwed up and I don’t have enough juice to get home.

I’m a little freaked out the BMS will screw up when I’m coming up the mountain thinking I charged to 70% before I left, when in actuality I charged to 50% and I don’t have enough range to get home.

You have now mentioned this twice like it's a common occurrence, but it's about the strangest thing I've heard. Where did you come up with something like this? Did you hear this fear mongering idea from someone? I've been on Tesla forums for about 10 years and never heard of something like that happening. It doesn't just lose its mind and start making up random numbers. A battery failure is a battery failure, but the BMS getting confused like you are describing just isn't a thing.

 

[AlanSubie4Life]

I'd get the LR if I were to do it again.

I commute 80 miles one way in SoCal weather mostly on AP in freeway 70-80 mph, and logged 105K miles on a 2018 LR Model 3 in 2 years time.

The 2018 LR had lost about 12% in the 2 years I run that route, last check was 270 miles at 100% SoC (310 new). The efficiency was about 80%, I burn about 200 EPA rated miles (for the 160 mile commute) daily. I charge using Wall Connector to 90% everyday. By 105K miles I have about 245 EPA rated miles at 90% SoC.
View attachment 839917View attachment 839918

So if that’s the LR RWD (not clear), that’s 16% after 100k miles. Anyway you can clarify.

Longer (160 miles vs. 140 miles)
Faster (1hr 10min or less)

And you still get 270Wh/mi.

but the BMS getting confused like you are describing just isn't a thing.

Agreed nothing like the OP is describing will happen except for battery failure. It is notable that there are provisions for the LFP to grab some buffer in cases of uncertainty though (been reported elsewhere and shown with SMT captures). But nothing near this severe. And also not sure exactly what it would look like. I think just a faster drop in SOC than expected. Not something to be concerned about here where there is so much margin in typical conditions.

 

[RoBoRaT]

So if that’s the LR RWD (not clear), that’s 16% after 100k miles. Anyway you can clarify.

Longer (160 miles vs. 140 miles)
Faster (1hr 10min or less)

And you still get 270Wh/mi.


Agreed nothing like the OP is describing will happen except for battery failure. It is notable that there are provisions for the LFP to grab some buffer in cases of uncertainty though (been reported elsewhere and shown with SMT captures). But nothing near this severe. And also not sure exactly what it would look like. I think just a faster drop in SOC than expected. Not something to be concerned about here where there is so much margin in typical conditions.

It's a 2018 LR AWD Model 3.

 

[AlanSubie4Life]

It's a 2018 LR AWD Model 3.

Ok, so yes, that’s another indicator that the OP should expect even better results on that RWD should that be his decision. So slower, shorter, and more efficient drive. And you have seen just 15% capacity loss (for “reasons,” it starts at 318rmi actually, not 310rmi) after 100k miles and four years which is great.

Definitely lifetime of 220-230Wh/mi seems possible in this particular RWD situation even after accounting for winter weather and rain. Which equates to 245mi max range when new to 0%, or 197mi after 20% capacity loss. So decent buffer for winter conditions, though for absolute worst case it could be slightly tricky at end of life, if no charging bailout options exist.

 

[Tippytj2]

Where's work? Is there a Supercharger (Old Fort) or CCS station (Biltmore Park) on the way for those worst-case scenarios?

While it's doable in most weather conditions, you might find the SR+ to induce some range anxiety in cold weather, particularly with snow. If you don't have intermediate charging options, the long range will provide you with significant extra buffer to cover cold weather or unexpected side trips and detours. Plus, the long range is way faster.

I’ll be driving Asheville to Greenville, SC, so down the mountain into SC. There’s a supercharger in south Asheville, but past there it’s 60mi of nothing until Greenville. LR is def appealing, just not sure I really

Where's work? Is there a Supercharger (Old Fort) or CCS station (Biltmore Park) on the way for those worst-case scenarios?

While it's doable in most weather conditions, you might find the SR+ to induce some range anxiety in cold weather, particularly with snow. If you don't have intermediate charging options, the long range will provide you with significant extra buffer to cover cold weather or unexpected side trips and detours. Plus, the long range is way faster.

i live in Asheville, but will be working in Greenville, SC. There’s a supercharger in south Asheville, which should help in a pinch if I’m cutting it close on a particular day for whatever reason. I am def intrigued by a used ‘21/‘22 LR w/ FSD for about the price of new.

 

[Tippytj2]

So if that’s the LR RWD (not clear), that’s 16% after 100k miles. Anyway you can clarify.

Longer (160 miles vs. 140 miles)
Faster (1hr 10min or less)

And you still get 270Wh/mi.


Agreed nothing like the OP is describing will happen except for battery failure. It is notable that there are provisions for the LFP to grab some buffer in cases of uncertainty though (been reported elsewhere and shown with SMT captures). But nothing near this severe. And also not sure exactly what it would look like. I think just a faster drop in SOC than expected. Not something to be concerned about here where there is so much margin in typical conditions.

Yeah, my understanding was that if you don’t charge to 100% with regularity to reset capacity and let the battery wallow around in the middle of SOC, because the LFP voltage is so flat across SOC, the BMS could make errors in estimate SOC that could ultimately result in sudden loss of range when getting to lower SOC and voltage drops off sooner than anticipated. There’s actually a guy on the other thread doing an experiment only driving his LFP between 30 and 70% SOC or something like that to see if this phenomenon happens. It does seem the error should be relatively small, but I haven’t seen data or anecdote about it.

Super helpful comments. Thanks guys! I think I’ll be fine with either vehicle until possibly much later in its life-cycle, at which point I should probably just get a new car anyway.

 

[Tippytj2]

I'd get the LR if I were to do it again.

I commute 80 miles one way in SoCal weather mostly on AP in freeway 70-80 mph, and logged 105K miles on a 2018 LR Model 3 in 2 years time.

The 2018 LR had lost about 12% in the 2 years I run that route, last check was 270 miles at 100% SoC (310 new). The efficiency was about 80%, I burn about 200 EPA rated miles (for the 160 mile commute) daily. I charge using Wall Connector to 90% everyday. By 105K miles I have about 245 EPA rated miles at 90% SoC.
View attachment 839917View attachment 839918

Super helpful. What would you say your variability is on this route for rain, wind or other variable conditions? Ie what is the lowest efficiency you’ve seen doing this route for 100k mi? It appears you have decent elevation on this route, have you found this to be a difference maker?