Is this daily commute realistic without Rex?

[ThreeEyes]

Hi, we're trying to choose between range anxiety and cost saving/greenness.

My daily commute will be 60 miles each way, 120 total.

99% freeway driving with 10% of that in slow freeway traffic.

If I am certain of an EVSE at work, will I ever have a problem traveling the 60 miles either way?

 

[epirali]

Hi, we're trying to choose between range anxiety and cost saving/greenness.

My daily commute will be 60 miles each way, 120 total.

99% freeway driving with 10% of that in slow freeway traffic.

If I am certain of an EVSE at work, will I ever have a problem traveling the 60 miles either way?

I don't have enough experience with the i3, but where do you live? What temperatures will you be driving in? And significant elevation change? Will you always be able to precondition the car before departure in cold weather? What is fast highway speed?

Any of these answers may make the 60 miles one way tricky, but others who drove through last winter can advise better. With a Brand new Leaf, which has comparable range, you would be pushing the limit in winter and probably not making it.

 

[jadnashuanh]

Without knowing the terrain around where you live, and the annual temperature ranges, it's impossible to tell. 60-miles uphill in the middle of a cold winter may not happen. Being able to precondition and setting a departure time at both ends will bring more regularity, and might be the differentiator.

How fast you drive, and how aggressively you use the climate control, whether most of the driving is with lights on, how much you run your high beams (at 4miles/Kw as the community average this time of year, that's 250W per mile...the high beams are 110W, or about 1% increase in load! That's basing 60mph, so 60 miles*250 watts verses the 110W an hour for high beams). Every little thing adds up. The i3 BEV in the USA has a heat pump, and that is more efficient than what's used in the REx. Little habits can make incremental changes to your available range. By preconditioning prior to leaving, and not keeping the cabin temp toasty, that will help, to and not as bad since you'll start out with it being nice after preconditioning. SOme find they can then leave the heat off. I'm a wuss, and won't.

If you lived in SoCal, where the temperature doesn't swing as far as most places (well, HI has probably the most stable temps in the USA), that would likely be a piece of cake. For some, it would push their comfort factor. My averages are creeping up now as the weather is warmer, and my overall average is 4miles/kw...but, at the end of winter in NH, it was about 3.7. With somewhere between 18-19Kw available in the batteries, that will give you an idea.

Highly suggest you arrange one of BMW's extended test drives and see. Most of the time, they loan you a REx, and that has slightly less efficiency than the BEV, but if you do it all on the batteries alone with a REx, you certainly should be able to do it with a BEV.

 

[cove3]

If it's a L2 charger at work, you may not have enough time to charge. What if the charger is down for a couple of days or in use or blocked by an ice or you get the afternoon off for xmas? Your profile suggests a phev. The 2016 Volt will give you 50 miles electric and you have a small 1.8L Rex for range anxiety and the occasional long multi hundred mile trips

Ron

 

[ThreeEyes]

Hi, we're trying to choose between range anxiety and cost saving/greenness.

My daily commute will be 60 miles each way, 120 total.

99% freeway driving with 10% of that in slow freeway traffic.

If I am certain of an EVSE at work, will I ever have a problem traveling the 60 miles either way?

I don't have enough experience with the i3, but where do you live? What temperatures will you be driving in? And significant elevation change? Will you always be able to precondition the car before departure in cold weather? What is fast highway speed?

Any of these answers may make the 60 miles one way tricky, but others who drove through last winter can advise better. With a Brand new Leaf, which has comparable range, you would be pushing the limit in winter and probably not making it.

Thanks guys.

Live in Los Angeles
Temperatures range from 50 - 100, usually warm
5% is hilly elevation
Can precondition
78 top speed
A/C usually on high cool

 

[ThreeEyes]

If it's a L2 charger at work, you may not have enough time to charge. What if the charger is down for a couple of days or in use or blocked by an ice or you get the afternoon off for xmas? Your profile suggests a phev. The 2016 Volt will give you 50 miles electric and you have a small 1.8L Rex for range anxiety and the occasional long multi hundred mile trips

Ron

Thanks. Work has 20 electric bays with more coming.

 

[Psisos]

I would suggest your freeway speed will have significant influence on whether the range is "comfortable". There are many examples of people who regularly get towards 100 miles but they are driving 56 on Eco pro +. At 70 and above you would be pushing the range which means daily anxiety! You also need to consider battery degradation if most days you are arriving on "fumes" so to speak. In a year those fumes may not be enough! And, should there be a major accident and freeway diversion you probably wouldn't have much in reserve! For the added flexibility adding the REx would alleviate any and all anxiety and give you other options for travelling. Put another way, with a REx you would be more inclined to run the battery right down because you have a fall back option should the battery give out....

 

[spinball]

I would not push a BEV that far every single day. Level 2 chargers are slow and there aren't enough DCFC in more areas (check Plugshare.com). But you don't want to have to stop daily.

In a year or two you probably can get a BEV to handle that distance but today I'd say that's too much for my comfort. REx would be fine, but you should still do the extended test drive and make sure you like it for your commute at those speeds. 78 may be normal for LA but it's quite fast for where I am!

 

[ThreeEyes]

Thanks all. looks like we're getting the Rex.

Just curious, what problem could we not like about driving at 75-78 in an i3 compared to any other car?

 

[jadnashuanh]

Thanks all. looks like we're getting the Rex.

Just curious, what problem could we not like about driving at 75-78 in an i3 compared to any other car?

The i3 has the equivalent of less than one gallon of gasoline of energy stored in it's batteries...yet, it can go over 100 miles if you have the right set of conditions...that's pretty impressive! Drag increases at the cube of the speed...not all of the power is used to move the vehicle (lights, radio, climate control, power assisted electric steering, etc.), a good portion of it is, so the faster you go, the more drag, the more energy it takes to keep you moving. Every car gets worse as you go up in speed once it's in top gear (the i3 only has one gear which helps).

If you are at work for what most consider a normal workday, you should be able to recharge your i3 more than 2x...if the L2 unit is a 30A or greater device. If you were talking about a 120vac outlet, yes, you probably would not get it recharged by the time you wanted to go home. Why saying a L2 was slow, don't know. In most places, there are no CCS units, so L1 or L2 are what everyone is using.

Colder temps affect range, but it gets much more of an impact if you cannot precondition and can't set a departure time, or you must make lots of short hops which causes the car to have to recondition itself multiple times. It's more efficient to just keep driving.

Nobody knows for sure how big the battery degradation will be with age or use on the i3. Very few if any devices out there manage their battery like the i3 does, reserving a buffer at both the top and bottom and only letting you use the middle portion while both heating and cooling it to keep it in the sweet spot. Then, if you're someone leasing the car, you probably don't care what happens after you sell it down the road...I do not believe you'd see any major problem during the term of a normal lease. It MIGHT become an issue as you neared the term of the battery (on the i3, that's 8-years or 100K miles in the USA).

It won't cost you anything...sign up for one of the extended test drives and see what happens on your normal commute with it. Then make your own decision. I'd want to drive your normal route during a normal day. Sitting in a traffic jam isn't as big an energy hog as driving 80mph down the freeway. You can see that on one of the screens, if you wish.

 

[psquare]

It won't cost you anything...sign up for one of the extended test drives and see what happens on your normal commute with it. Then make your own decision. I'd want to drive your normal route during a normal day. Sitting in a traffic jam isn't as big an energy hog as driving 80mph down the freeway. You can see that on one of the screens, if you wish.

I think that's very good advice. Jim is also right to point out potential battery degradation, which none of us really know about at this point in time.

Based on my experiences driving my i3 in english summer temperatures on motorways, I'd say I could arrive at a location that's 60 miles away with 15-20% charge left. During my journey, once I would reach 25% SOC remaining (last quarter), I would engage the REx. I do this to be on the safe side in case the charging unit at my destination does not work, in which case I would a) look for a different unit or b) ensure the REx tank is topped up. This should see you through under all eventualities. On a warm day I probably wouldn't bother with engaging the REx - it really depends.

I think the main question is how comfortable you would feel burning potentially some petrol on a daily basis. Personally, I would have decided against a REx (or an i3 in general!) if I would have to use it as regular as that, but it's a personal choice.

 

[epirali]

It won't cost you anything...sign up for one of the extended test drives and see what happens on your normal commute with it. Then make your own decision. I'd want to drive your normal route during a normal day. Sitting in a traffic jam isn't as big an energy hog as driving 80mph down the freeway. You can see that on one of the screens, if you wish.

I think that's very good advice. Jim is also right to point out potential battery degradation, which none of us really know about at this point in time.

Based on my experiences driving my i3 in english summer temperatures on motorways, I'd say I could arrive at a location that's 60 miles away with 15-20% charge left. During my journey, once I would reach 25% SOC remaining (last quarter), I would engage the REx. I do this to be on the safe side in case the charging unit at my destination does not work, in which case I would a) look for a different unit or b) ensure the REx tank is topped up. This should see you through under all eventualities. On a warm day I probably wouldn't bother with engaging the REx - it really depends.

I think the main question is how comfortable you would feel burning potentially some petrol on a daily basis. Personally, I would have decided against a REx (or an i3 in general!) if I would have to use it as regular as that, but it's a personal choice.

Keep in mind in U.S. without coding we can't hold state of charge. But in most of LA that shouldn't be an issue unless OP lives on top of a hill. But I have no idea if Rex can maintain 78 mph without draining the battery. And trying to go 55 in LA when it's actually moving is a hazard in my opinion. Coding the i3 and turning on hold SOC may be useful.

 

[epirali]

Hi, we're trying to choose between range anxiety and cost saving/greenness.

My daily commute will be 60 miles each way, 120 total.

99% freeway driving with 10% of that in slow freeway traffic.

If I am certain of an EVSE at work, will I ever have a problem traveling the 60 miles either way?

I don't have enough experience with the i3, but where do you live? What temperatures will you be driving in? And significant elevation change? Will you always be able to precondition the car before departure in cold weather? What is fast highway speed?

Any of these answers may make the 60 miles one way tricky, but others who drove through last winter can advise better. With a Brand new Leaf, which has comparable range, you would be pushing the limit in winter and probably not making it.

Thanks guys.

Live in Los Angeles
Temperatures range from 50 - 100, usually warm
5% is hilly elevation
Can precondition
78 top speed
A/C usually on high cool

Another good thing for you is Rex doesn't have room for a heat pump (resistive less efficient heating) but you won't almost ever need heat.

 

[jadnashuanh]

At 78mph, from my take on things, you will be on the verge of breaking even, and discharging the battery especially if you're going up a grade. The REx won't run at full output below around 56mph, so it would likely be running full tilt at 78mph. Keep in mind, the REx is only a 34Hp engine. Just how fast do you think a 34Hp motor in a car that weighs nearly 3,000# (with the REx, not counting load) can go? The battery is fully capable of powering the 170Hp electric engine and the only time you use all of that is when your foot is floored, but once you get down to the low end of charge, to protect things, they start to limit the power out. The power is always coming out the batteries, and at some point, the controls will limit what comes out to what's going in - 34Hp is maybe a bit over 22Kw allowing some for losses, not knowing the efficiency of the power conversion. At say 80mph, that's 22000/80=275W/mile where the average user is getting only about 250W per mile to drive a mile (hope I did that math right!). IOW, there MIGHT be a bit of excess. Running the a/c at full blast, or accelerating, or climbing a grade, and you'd definitely be bleeding charge. I do not know the actual energy conversion efficiency of the REx in the i3.

Now, the BEV could very possibly make it all the way in the LA basin, depending on how fast you really can travel, and how far you go on the freeways. Those can go from full speed ahead to stop and go in an instant from my limited experiences in that area. Luckily, an i3 doesn't draw much power while stopped...it's much more efficient than an ICE sitting there unless it has auto start/stop and it's in use - many people turn it off.

Anyone have firm information on the REx to generator output values? Mine are just taking straight energy conversions with a WAG at the efficiency.

 

[spinball]

I was suggesting L2 is too slow if you have to use in the middle of your commute each day. If you know for sure you will be able to have a spot to charge at work, then L2 is plenty.

As many said already, the extended test drive is worth your time to pursue. It's a lot of money to commit without making sure you are getting the right tool for the job. I drove 3 different i3s before taking the plunge, one of them overnight so I could experience my commute and a charging cycle.

Also there is a thing you may experience called "gas anxiety". This is FAR less worrying than "range anxiety", but it's still a real thing for some people. I have a streak going of 17 days without using any gas at all and I'm not too thrilled about breaking it! :lol: I also know my cost per mile is around 3 cents on electric vs something like 8 cents on gas (and 13 cents/mi on my old gas car).

 

[janner]

Provided you can charge fully after your morning commute you should be alright for 60 miles. Range will vary with temperature and lights/heater/aircon but it will also vary with speed - you can always go slower at first until you're confident of your range. For the BEV at 70mph your (typical) range should be around 77 miles and at 60 mph about 96miles whilst at 50mph the range is 115miles.

In terms of chargers at your place of work, a Level 2 charger (2 - 3 hours) would be ideal and would allow you to pre-condition (battery and interior) before leaving work, providing your employer lets you stay plugged in all day. If you only have a level 1 charger (at 240v) your charge time will be 6 - 8 hours and, I think, you'll only be able to precondition your interior and not your battery. You don't need a rapid (20-30 min) charger because then almost certainly your employer would want you to unplug once you had charged.

 

[MarkN]

At 78mph, from my take on things, you will be on the verge of breaking even, and discharging the battery especially if you're going up a grade. [...] 34Hp is maybe a bit over 22Kw allowing some for losses, not knowing the efficiency of the power conversion. At say 80mph, that's 22000/80=275W/mile where the average user is getting only about 250W per mile to drive a mile (hope I did that math right!). IOW, there MIGHT be a bit of excess. Running the a/c at full blast, or accelerating, or climbing a grade, and you'd definitely be bleeding charge.

Once a week I drive our i3 REx on a 110 mile round trip to work, mostly on I-25 with a 75 mph speed limit. Usually the traffic slows down below 70 at about the same time the REx engages, but yesterday it was flowing at full speed. In Eco Pro mode with the air conditioner running the REx could not maintain the charge with cruise control set to 71 mph.

Regarding the math: 22000 watts/80 miles per hour = 275 Watt-hours/mile, not watts/mile.

 

[Jeffj]

REx has lower power in CO due to the altitude. Not sure what the actual reduciton is, but we get less than the full 34 hp.

 

[Jaypi]

I would do it - what happens when you have to take a de-tour because of an accident or you want to drive somewhere on the way there. Just get a Rex.

 

[mjk]

I leased a Leaf in 2013 for the purpose of evaluating the practicality (for me) of driving pure electric; that was after a year of driving a Prius Plug-In which, even though it had an electric range of about 11 miles, allowed me to drive most of my miles electric because I plugged in (Level 1) at home every time I came back from running errands.

I didn't have range anxiety as much as charging anxiety. The questions of: a) finding an available L2 charger that's working; or, b) finding an available and working DCFC charger made me feel that—again, for me—pure electric was not practical.

Before my Leaf lease ended, I bought the i3 REx. And I haven't been sorry. It allowed me to scale back to a single car for all travel. Despite admonishments from many that the REx is not intended for long-distance travel (something I've yet to see documented by BMW), I've made numerous 250-mile day trips without problems. On those trips, if I find an available, working DCFC, I charge up if time warrants; otherwise, I let REx kick in and fill the void.

Put another way, if you buy BEV and it doesn't meet your needs, you can't add REx. If you buy REx and electric meets all of your needs, you can NOT use the REx.