20" wheels, Rex vs. Non-Rex, 2014 vs. 2017

[YKK]

My first look was at 2017 REX models but the price difference between a 2017 and 2014 seems to be around 6-8k (~14k vs. ~20-22k) at comparable mileages. The only major difference between the two is the battery capacity, correct? What is the actual range difference taking into account the age and say... 50k miles? I've really shifted my search to 2014's due to the cost savings but not sure if that's a bad idea long term. My next question is about REX that I'm hoping some REX users would be able to chime in on. Do you ever actually use it? Is it "okay" to just never use it or will that cause problems eventually? Maintenance an issue for it? I like the idea of having security but I'd like to know the costs besides increased purchase price. Next question is the rims. All the loaded 2014's I've seen have 20" rims. Is this just because anyone paying extra for the leather+NAV also springs for the wheel upgrade or is it actually part of the Terra package? Reading about the 20" here and other places online it seems they are simply functionally not as good as the 19" and will result in a rougher ride.

 

[eNate]

I was trapped in the "need 250 miles" noise and was looking half seriously at the Kona eNiro.

I paged through my Google Maps history for my previous six months and noted my normal daily driving averaged around 45 total miles, and I obviously had higher mileage days here and there, with about 140 being what I'd consider a "normal" high-mileage day (i.e. errands, meeting friends for lunch, but not a planned trip).

So based on that, I made the decision that I could get by with an earlier 60Ah i3, but that I'd be better off with a 2017.

I should note that this decision was weighed heavily by wanting to go the BEV route, but also that I have a somewhat disjointed charging routine where I don't charge at home overnight.

BTW my search also excluded models with 20" wheels. I drove both, on a handful of test drives, including a 2 hour test drive on 20's with the family. The i3 is definitely not an example of a "compliant ride" and the 20's, in my humble opinion, only exacerbated that.

 

[alohart]

My first look was at 2017 REX models but the price difference between a 2017 and 2014 seems to be around 6-8k (~14k vs. ~20-22k) at comparable mileages. The only major difference between the two is the battery capacity, correct?

Correct.

What is the actual range difference taking into account the age and say... 50k miles? I've really shifted my search to 2014's due to the cost savings but not sure if that's a bad idea long term.

The range difference is roughly proportional to the usable battery pack capacity difference: ~45% greater for the 94 Ah battery pack assuming new capacities.

A number of owners of 60 Ah i3's (2014-2016) are reporting significant loss of actual range (including me). Whether this is due to actual battery cell degradation or the battery management system decreasing the usable capacity to minimize the rate of degradation in hopes of minimizing the number of battery capacity warranty claims remains unknown. The effect on the driver is the same: less usable range.

Similar reports seem rare with the 94 Ah battery pack (2017-2018). Whether that will change in a couple of years as 94 Ah battery packs age and experience more charge/discharge cycles also remains unknown. My sense is that the 94 Ah battery cells seem to be degrading less slowly.

All the loaded 2014's I've seen have 20" rims. Is this just because anyone paying extra for the leather+NAV also springs for the wheel upgrade or is it actually part of the Terra package?

The 20" wheel option was available for all trim levels and not standard in Tera World.

 

[robthebold]

My next question is about REX that I'm hoping some REX users would be able to chime in on. Do you ever actually use it? Is it "okay" to just never use it or will that cause problems eventually? Maintenance an issue for it? I like the idea of having security but I'd like to know the costs besides increased purchase price.

I've needed the REX once in the year I've owned my '17 94 Ah. And that was optional, since I wanted to see how it worked. Could've taken my wife's gassed-up hybrid rather than my mostly-discharged i3 on a 40 mile both ways round trip.

Next question is the rims. All the loaded 2014's I've seen have 20" rims. Is this just because anyone paying extra for the leather+NAV also springs for the wheel upgrade or is it actually part of the Terra package? Reading about the 20" here and other places online it seems they are simply functionally not as good as the 19" and will result in a rougher ride.

If you need tires for winter weather -- meaning snow, ice or temps below 40F -- and don't want a second set of wheels and tires, you'll need the 19" ones. Only Summer tires are available for the 20" rims -- there's no snow tire or all season M+S tire available for that wheel. If you won't be using the car in winter conditions, you can base your decision on looks, comfort, handling and vulnerability to road hazards.

 

[jadnashuanh]

Many, not all, i3s came with the staggered wheels. While some have installed the winter tires on the wider, rear wheels, it's not a great idea, so you may still need to buy at least a pair to mount winter tires there. The advantage, too, with having them all the same is that you would have a spare, should you want one, as it will fit anywhere. Depending on the winter tire you get, it may only go on one side, so that is a consideration, but you could drive it on either side long enough to get the damaged one repaired or replaced.

 

[joni3s]

A i3S owner has fitted wider nokian R3 winters on his 431 style 20". Folks have fit them on their i3's with spacers and flares IIRC.

The rims are available for sale from BMW, not cheap, but not custom prices earlier. A spare set of winter tires in cold weather is recommended if you have the summer performance tires, however it appears many get away with not changing them, but thats a risk for less $2K (for a full set, not a tire swap) i didn't take, given that i'm saving that in gas over 6 mos of use and only using the winter tires for 3-4 months, if that.

Depending on your local road conditions, the 19s with larger sidewall should feel nicer on bumpier roads. 19s are also less expensive and more easily source-able from what I've seen.

Rex needs to run and the computers will engage maintenance mode every couple of weeks to make sure it is, but recent discussion alludes to using it more often for benefits.

I have a 70-80 mile RT commute with a 94Ah i3S and will engage rex every third day or so for 25 miles at ~70mph. Gas in my locale is cheaper or similar than 3rd party electricity right now and I use a varied assortment of DC, LVL2 and OUC charger throughout the week. I am never at fear of being out of batt or gas which in my ~25F-40F winter sees total range of ~170m give or take. 90% highway miles.

Most people complain about a couple of things: audio system, rim size, coach doors.. but each of those has their proponents and detractors. For me i have base audio (i am ok with it), 20" wider wheels (i like them) and don't mind the extra steps that comes with the coach doors and I am frequently having 4 passengers..

 

[Obioban]

My first look was at 2017 REX models but the price difference between a 2017 and 2014 seems to be around 6-8k (~14k vs. ~20-22k) at comparable mileages. The only major difference between the two is the battery capacity, correct? What is the actual range difference taking into account the age and say... 50k miles? I've really shifted my search to 2014's due to the cost savings but not sure if that's a bad idea long term. My next question is about REX that I'm hoping some REX users would be able to chime in on. Do you ever actually use it? Is it "okay" to just never use it or will that cause problems eventually? Maintenance an issue for it? I like the idea of having security but I'd like to know the costs besides increased purchase price. Next question is the rims. All the loaded 2014's I've seen have 20" rims. Is this just because anyone paying extra for the leather+NAV also springs for the wheel upgrade or is it actually part of the Terra package? Reading about the 20" here and other places online it seems they are simply functionally not as good as the 19" and will result in a rougher ride.

Most of the reliability issues with the i3 stem from the REX. If you don't NEED it (most people don't, at least with a 2017+), you should avoid it IMO. It also reintroduces all the maintenance of an ICE car (vs just brake fluid for the BEV) and makes the car >10% heavier (bad for everything).

19s vs 20s... I've very pro small wheels (running 17s and 18s on my M3s and M5), but I had to get 20s for the i3 because you can only get all seasons on the 19s. I need summer tires in the summer, so had to get 20s (running 19s with snows in the winter).

My first look was at 2017 REX models but the price difference between a 2017 and 2014 seems to be around 6-8k (~14k vs. ~20-22k) at comparable mileages. The only major difference between the two is the battery capacity, correct?

Correct.

What is the actual range difference taking into account the age and say... 50k miles? I've really shifted my search to 2014's due to the cost savings but not sure if that's a bad idea long term.

The range difference is roughly proportional to the usable battery pack capacity difference: ~45% greater for the 94 Ah battery pack assuming new capacities.

A number of owners of 60 Ah i3's (2014-2016) are reporting significant loss of actual range (including me). Whether this is due to actual battery cell degradation or the battery management system decreasing the usable capacity to minimize the rate of degradation in hopes of minimizing the number of battery capacity warranty claims remains unknown. The effect on the driver is the same: less usable range.

Similar reports seem rare with the 94 Ah battery pack (2017-2018). Whether that will change in a couple of years as 94 Ah battery packs age and experience more charge/discharge cycles also remains unknown. My sense is that the 94 Ah battery cells seem to be degrading less slowly.

All the loaded 2014's I've seen have 20" rims. Is this just because anyone paying extra for the leather+NAV also springs for the wheel upgrade or is it actually part of the Terra package?

The 20" wheel option was available for all trim levels and not standard in Tera World.

The 94aH battery actually has 57% more capacity than the 60aH battery

I wonder how much of the decreased wear rate of the 94aH battery is because it sees less cycles per mile driven than the 60aH battery. Either way, I'm now 50,000 miles into my 94aH, all of it driven hugely inefficiently (so more cycles), and including winter use, and no degradation so far.

 

[alohart]

The 94aH battery actually has 57% more capacity than the 60aH battery

That's gross capacity. The nominal usable capacity of the 94 Ah battery pack is 27.2 kWh compared with 18.8 kWh for the 60 Ah battery pack making the nominal usable capacity of the 94 Ah battery pack 45% greater. The 60 Ah battery pack's usable capacity is 87% of its gross capacity compared with 82% for the 94 Ah battery pack. The larger percentage of unusable capacity of the 94 Ah battery pack has likely helped reduce its cell degradation rate.

The EPA range rating for the 94 Ah BEV is only 41% greater than the 60 Ah BEV due a lower percentage of usable battery pack capacity as well as the heavier weight of the 94 Ah battery pack.

 

[Valleeboi02]

The Terra World trim is only the top trim when it comes to the interior and it has nothing to do with the options you can choose.. I've seen Terra trims without a rear camera, business nav, no Hardon speakers, no ACC or no self parking and no front end Collision warning..

Yes, the only difference in the 2014 model and the later 2017 model is the battery capacity and interior colors..
The 2017 will give you at least 45% more battery range during idea conditions if the battery hasn't degraded much..

Stay away from i3s with more than 40k miles, but if you can get it for under $10k it might be a good deal.. Check battery degradation to see the health of the battery. A 2014 i3 should have a normal battery degradation of about 1.5 percent after 6 years of normal level 1 and level 2 charging..

20 inch wheels were an option on all model years regardless of trim levels..
20 inch wheels only come with summer tires and you would need to buy the 19 inch wheels if you want all season and or winter tires.

2017 seems to be the most popular since it has the 94Ah battery.. If you only drive 50 miles round trip in a day, the BEV 2014 version will be fine.. If you can't always charge while on the go, the 2014 REx might be your best bet. Yes, the REx requires oil and oil filter changes.. Many people use the REx to hold the battery at 75% charged so they can drive longer distances, usually for freeway driving.
I've done a 200 mile round trip with the REx holding the battery at 70% on the freeway at 60mph. The battery did drop some because the REx could not always hold the charge because I was driving hard at times on the freeway.

Just buy whatever i3 suits your lifestyle and budget.

 

[alohart]

The Terra World trim is only the top trim when it comes to the interior and it has nothing to do with the options you can choose.. I've seen Terra trims without a rear camera, business nav, no Hardon speakers, no ACC or no self parking and no front end Collision warning..

Yes, the only difference in the 2014 model and the later 2017 model is the battery capacity and interior colors..

Not entirely true, at least for the 2014 U.S. model. Giga and Tera World include Comfort Access and the Universal Garage Door Opener, neither of which could be added as an option on Mega World i3's. I believe that at some point, Comfort Access and the Universal Garage Door Opener also became standard with Mega World.

A fourth trim level, Deka World, was added at some point. It has even fewer standard features than Mega World. One significant option that's missing and could not be added is LED low beam headlights.

Then there were the Value Package i3's. If I recall correctly, they had an odd mixture of options. Few were sold, so the chance of encountering a used one is small.

Because of the variety of standard features available across various trim levels and model years, those potential buyers who care about such details should use a BMW VIN decoder Website to determine exactly what options and features a particular i3 includes.

2014 i3 should have a normal battery degradation of about 1.5 percent after 6 years of normal level 1 and level 2 charging..=

This is certainly not true for all 2014 i3's. The Idaho National Library bought and tested 3 new 2013 i3 BEV's and measured their usable battery pack capacity over ~15 months and ~12k miles. All of them lost ~7.5% of their new usable capacity. A 4th 2014 BEV lost 3.5% usable battery pack capacity over only 3 months and 4k miles.

Our 2014 BEV has lost ~15% of its new usable battery pack capacity over 5.5 years and only 10k miles which is consistent with the Idaho National Labs findings. Its battery pack has led an ideal life having never experienced temperature extremes, has rarely remained at very high or low charge levels, has been DC fast charged only twice, is usually AC Level 2 charged at only 3.3 kW, and has usually operated over a low depth of discharge.

94 Ah battery packs seem to be losing usable capacity at a significantly lower rate which is another reason why I would recommend buying a 94 Ah i3 if one could afford to do so.

 

[Anonymous]

Our 2014 BEV has lost ~15% of its new usable battery pack capacity over 5.5 years and only 10k miles which is consistent with the Idaho National Labs findings.

Would be nice if there were other more comprehensive testing done, for consistency, and peer review of the testing methodology, as the results anecdotally seem spotty. In Green Car Reports an owner-review shows a 2014 high-mileage REx with almost no loss of capacity.

https://www.greencarreports.com/news/1110512_bmw-i3-rex-owners-3-years-with-range-extended-electric-car.

For myself, with a 2015 REx that I bought over a year ago with 9,600 miles on the clock, I've seen no appreciable loss of capacity now at 18,998 miles. Car drives mainly short hauls at between 30 and 50 miles an hour, gets fully charged on a level 2 charger every two to three days, lives in a climate where winter temps average around 40F - 50F degrees but can go down into the 30F's, and summer temps average 80F, but can go above 100F . Today it is 60F degrees, and my electric mileage shows 76 miles (with an EPA estimate of 72 miles, new). When the temp gets up into the 80Fs, I get 80-82 miles (all in Comfort mode).

 

[alohart]

Would be nice if there were other more comprehensive testing done, for consistency, and peer review of the testing methodology, as the results anecdotally seem spotty.

True, especially since i3 and EV drivers in general can't determine battery capacity loss very precisely due to so many variables that affect actual range.

Batt. Kapa. max is a calculated value based itself when extrapolating the energy that would have been added to a battery pack were it being charged from a true empty to a true full. Batt. Kapa. max has varied on our 2014 BEV by 4 kWh over several months in both positive and negative directions with no trend in either direction. However, I've made no attempt to read Batt. Kapa. max repeatedly under the same conditions which would probably reduce the randomness.

The usable capacity of an i3 battery pack is the usable capacity of the weakest of 96 battery cells because they're all connected in series. The capacity of those battery packs with some strings connected in parallel (e.g., Tesla battery packs) isn't as affected by a weak cell, but then there are more cells which would increase the probability of a weak cell.

I'm beginning to believe that the 60 Ah cells aren't as high quality as the 94 Ah and probably 120 Ah cells because the 60 Ah cells were one of Samsung SDI's earliest cells. Maybe the probability of weak 60 Ah cells is greater, and maybe the cell chemistry is more prone to degradation. We may have been unlucky to have a battery pack with one or more weak cells. Improvements almost certainly have occurred with Samsung SDI's experience.