Can i3 Rex do a 98 mile roundtrip commute at freeway speeds

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rihallix

Member
Joined
Apr 8, 2017
Messages
7
I have a 98 mile roundtrip commute in the Bay Area. Probably 80% of that is at highway speeds (60-70mph) and the rest crawling along 19th avenue in San Francisco.

(1) Can the i3 or i3 Rex do this?

(2) Could it do the trip entirely as an EV or would it need to use some gas dropping the mpg / efficiency?

Thanks in advance. This is for the Bay Area - so no real winter conditions, at least very rarely does it drop to freezing here.
 
rihallix said:
I have a 98 mile roundtrip commute in the Bay Area. Probably 80% of that is at highway speeds (60-70mph) and the rest crawling along 19th avenue in San Francisco.

(1) Can the i3 or i3 Rex do this?

(2) Could it do the trip entirely as an EV or would it need to use some gas dropping the mpg / efficiency?
. . .
In May 2016 I bought a 2014 BMW i3-REx (60Ahr) because it has a total range of 150 miles and could reach Nashville TN from Huntsville AL without refueling or charging. Last month I tested my assumption and it worked as expected. However, I'd already done a 463 mile and each way a 700 mile vacation to Oklahoma.

Mine is coded so once I get on the highway in EV and the SOC reached 75%, I start the REx and drive the tank dry. I pay the warm-up cost just once per tank so I have it coded and run the tank dry. Then I continued the rest of the trip on EV.

Around town, I use EV and often take lunch at places with free EVSE chargers. So in daily use, no problem in EV-only mode supported by lunch time charge or after work, shop where there are free chargers. Charging rates:
  1. 40 kW Fast DC Charger - in 30 minutes, adds ~50% SOC
  2. 32A L2 charger - adds 20% every hour
  3. 12A L1 charger - adds 5% per hour

With the REx, you have options to 'tickle the dragon' and run the battery down. But then I live in Huntsville AL and folks here with their commuter pick-up trucks think the BMW i3-REx getting 40 MPG is terrific.

Bob Wilson
 
One of the issues with any EV is that the battery won't drive the car as far when it gets cold outside. But, SoCal doesn't traditionally get cold, at least not for long. 98-miles with the 2017 BEV at mostly highway speeds might be pushing it, but a 2017 REx should not have any problems, and you might make it all of the way only on the battery. The original REx could make it, but you'd almost certainly need to use some gas each day, but if you could slow down a little, may squeak by. The original BEV, no way without a stop to recharge the battery at those speeds, IMHO, but possible if you could slow down even a little, but you'd be very close to empty.
 
jadnashuanh said:
One of the issues with any EV is that the battery won't drive the car as far when it gets cold outside. But, SoCal doesn't traditionally get cold, at least not for long. 98-miles with the 2017 BEV at mostly highway speeds might be pushing it, but a 2017 REx should not have any problems, and you might make it all of the way only on the battery. The original REx could make it, but you'd almost certainly need to use some gas each day, but if you could slow down a little, may squeak by. The original BEV, no way without a stop to recharge the battery at those speeds, IMHO, but possible if you could slow down even a little, but you'd be very close to empty.

Thanks, I'm in Northern California - still not too cold. Sounds like the 2017 REx should easily do it, possibly using a little gas, maybe needing refueling once a week ?

Looks like it should use 27 KwH for a 100 mile roundtrip according to this article https://www.extremetech.com/extreme...al-for-evs-is-100-plus-miles-range-if-not-200 if book figures are to be believed. (insight most welcome)

I'm assuming 12c per KwH so that comes out at $3.24 per roundtrip; compared to a 30mpg gas vehicle which would consume $15 of gas for the same journey with gas at $4.50 per gallon. So 78% less fuel cost than a regular gasonline powered vehicle.
 
The BMW app for the i3 reports both your efficiency and the 'community'. The community's average efficiency is 4-miles/Kw. That's real-world use from all i3 drivers. Some regularly achieve better, some worse, depending on the area and their driving habits. The faster you drive, the lower it gets, but some of that is the 'quality' of your driving. Maintaining a steady speed is more efficient than surging. I've seen days with it showing over 5.6-miles/Kw, and I've had days (super cold, short trips) where it has fallen to less than 2-miles/Kw. Right now, mine is 3.8, but will rise as the spring and summer arrive with warmer temperatures. We've had days when it barely gets above zero F. Just heating the cabin can take a big hit (it's worse on the REX, the BEV has a primary heat pump, with resistance heating as a backup...the Rex only has resistance heating).

The adaptive cruise control can maintain a safe gap while following the car in front and smoothing out your driving (you can adjust the desired gap). That will normally improve upon a typical individual's efficiency in many situations.

Many dealers will loan you a REx for a couple of days...that's the best way to determine if it can do the job you want.
 
I have a UK 94 Ah REX and I drove 107 miles to the Ecotricity CCS fast charger on the motorway with the adaptive cruise control set to 70mph in Eco mode. I got there with a claimed 20 electric miles remaining.
Admittedly this was in the daytime with preconditioning and cabin temperature set to 18C with external around 15C, so it's going to be worse at night in the rain or below freezing.
I use the car for a 60 mile commute and no REX use. I didn't use the REX on the 197 mile trip but that was with two 30min fast charges. The second might not have been needed, but I wasn't sure I could charge in the garage at 13A and it was predicting about 5 miles left at destination.
On the way back I'll try a single 30min fast charge and see how much REX I need. It's nice having the REX as a backup of the fast chargers are out ;)
 
As a previous poster suggested try to find a BMW dealer who offers the extended test drive on the i3. Then you can try the car on your actual commute.

Alternatively you can do what we did before committing to 2017 REX and find one to rent. We found a local one on Turo that had been coded to allow the 75% hold SOC and my wife took it to work on her 70 mile round trip commute. I think you'll find there are other ways to rent one up there in the Bay area if you want to give it a try. For us it was well worth a couple hundred bucks to know for sure.
 
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