Refueling A BMW i3 REx On A Roadtrip

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Originally published on The Electric BMW i3.
By Tom Moloughney

I know many readers here have spent countless sleepless nights pondering the the age-old question: How long does it take to refuel a BMW i3’s tiny gas tank?

Well maybe not, but I have had people argue that driving the i3 REx on an extended trip would be very inconvenient because they would have to stop to fill up the gas tank every 50-60 miles. I’ve done quite a few road trips with my i3 REx, and stopping once an hour for a couple of minutes to refill the tank never really bothered me much.

I wrote a post last year which detailed a 462 mile round trip I made to Vermont from my home in New Jersey and refueling was one of the topics that many people commented on. On that trip, I had to stop for gas a total of seven times, as I only recharged the car once, which was at my destination. I drove 111 miles on battery, 351 miles on the range extender and used a total of 9.87 gallons of gas, averaging 35.5 mpg.

In that post, I wrote that I found it funny how quickly the gas tank fills because it’s only 1.9 gallons. My wife started timing how long it took to stop for gas and we averaged a little over two minutes. I remember wishing we had recorded one of the gas breaks so we could demonstrate just how quick you can pull off the highway, fill up, get back into the car and back out onto the highway. I made a note that the next time we drove back up to Vermont, we would do just that.

So last week we made the Vermont trip again, and as planned we recorded one of the gas stops:

As you can see, I started the stopwatch before we exited the highway, and stopped it when we were back on the highway. I didn’t jump out of the car and rush like a NASCAR pit crew filling up. I took my time and even spent a couple extra second topping off so I’d get every drop that I could into that tiny tank and we still did it in under two minutes.

The point of the exercise was to demonstrate that it’s really not that inconvenient to make a quick gas break about once every every hour. I will qualify that statement with the fact that here in the Northeast there are gas stations everywhere. It seems that I’m never more than a couple miles from one, so when I’m doing these long drives I can plan the stops at convenient intervals when the tank is nearly empty. While that is the case for many large city and suburban areas throughout the country, there are plenty of rural areas where gas stations aren’t as prevalent, and the small gas tank would be a problem. The i3 REx most likely isn’t well suited for use in those areas. But hey, BMW calls it a “city car” after all.

As I mentioned above, when I made the trip last year I only did 111 miles on battery and drove 351 on the REx. This year I was able to drive 270 miles on battery, and needed only 184 miles with the range extender maintaining the battery state of charge. This was possible because of the always improving charging infrastructure. I was able to stop twice (once each way) at Prestige BMW in Mahwah, NJ and use their new DC fast chargers. Also, on the way home I stopped for a couple hours at a friend’s house who just recently installed a 240v level 2 EVSE in his garage. These stops allowed me to more than double the all-electric miles for the trip, and I only needed 4.9 gallons of gas for the 184 miles I drove with the range extender running, as I averaged 37.5 mpg.

I now have over 36,000 miles on my i3 after seventeen months of ownership, and only about 1,750 of those miles were on the REx. The range extender has been a great feature and I’m still very happy I got it. It does what it is supposed to; it gets you home without worrying about finding a charging station on the rare days that the electric range isn’t enough, and it enables the occasional long road trip. There are limitations though, and extreme hill climbing while the REx is running for prolonged periods at highway speeds, can result in reduced power. Fortunately I’ve never had that happen to me but I don’t really have any big mountains which I need to climb. On my Vermont trips I set the Active Cruise Control to 70 mph and have never had an issue yet, even though there are some prolonged climbs at the end of the trip. I did get the “Reduced Power Possible” warning once though, as the state of charge hit a low point of 2% once. However it held there until I crested the climb and once I was on flat ground the SOC climbed back up to about 6%. I left the cruise at 70 mph because I actually wanted to see at what point it would go into reduced power mode, but it never happened.

Still, in a perfect world I’d prefer a 150 mile, all-electric-range i3 combined with adequate DC fast charge infrastructure. Personally, I really don’t need 250 or 300 miles of range, and I’d rather not pay for it. However, even though the infrastructure is improving, I think 200 miles of range is probably more acceptable until DC fast chargers are ubiquitous. It appears with Nissan and Chevy poised to bring 200 mile EVs to market in the coming year, the “affordable” electric vehicle market is going to get very interesting. BMW’s CEO recently announced that the 2017 i3 will have a longer all electric range also, but didn’t comment on exactly how much more. That’s good news because as much as I like how the REx works, and how quickly I can refill the gas tank, I’d still much prefer going on battery alone.

Reprinted with permission.

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31 thoughts on “Refueling A BMW i3 REx On A Roadtrip

  • Pretty cool.

    Wish I could afford one….

    • I’m with you. The i3 was one of my favorite cars to drive, I enjoy the look of it and the carbon fiber life module is pretty fantastic as well. This article actually makes me thing the ReX might not be a terrible idea. It would be ideal to DC fast chargers at the gas station so you could fill up the ReX tank, drop it on the DC fast charger while grabbing a coffee and go…

  • That is like driving around with your low fuel light on permanently. Talk about range anxiety.

    • Sure, but EV drivers are already used to that feeling. I don’t even flinch anymore when I pull into my driveway with 10 miles remaining on my LEAF.

      I just hope the gas gauge in the i3 is more accurate than most 10-gallon tanks I’ve driven. The only reason driving with your fuel light on is stressful is because you have no other indication of remaining capacity. If the gauge goes from full to empty accurately as you empty the 2-gallon tank, it’s much less worrisome.

      • Yes, I’ve found it to be very accurate.

      • Wish that BMW would have used the space and cost of the range extender to put additional batteries in the car to add another 15-20 miles to the EV range. Would be way more compelling (as a Leaf alternative) as a pure EV with a 95+ range.

      • That is fine in the City.

        That is not fine on a road trip, where gas stations can be 40 miles apart.

  • Why not carry two five gallon spares for those rural trips? Pull over anywhere and fill up. Ten gallons plus the two in the tank plus 100 miles electric equals a range 550 miles. Who needs more than that in a day? And if you do, just fill up the spare cans.

    By the way, the BMW i3 rex is a perfect model for an off grid house. PV and battery and a (propane) range extender for those 3% of days when you fall short with solar electric. The electric car with range extender such as the volt and bmw will help people understand just how easy it is to use the same model for a stationary house. The only difference is the panels on your roof will charge both you car and your house.

    And lastly, I still think a propane range extender would be superior to gas…since it is far cleaner and does not go stale as the gas will if not used within a few months.

    • That has been asked before but I can’t really say I’d ever consider it. There is no way you could refuel as quickly with your own can, plus they always leak so you’ll end up with gas (and the smell of it) on you. You still have to stop to refill the gas tank, so what is really the advantage?

      Wherever I drive there are gas stations everywhere, usually within a couple miles so I have no interest in carrying a gas can in my car which will eventually spill and smell up the entire cabin.

      However if you live in a rural area where there aren’t gas stations easily accessible, then I could see possibly carrying a 2.5 gallon can in the front trunk (it will only fit about a 2.5 gallon can up there). However for me, locating a gas station is never an issue.

      • I can see why you wouldn’t want to carry gasoline around in a can.

        I think it’s dangerous and smelly.

        • Umm, but you are carrying gas in a 2 gallon can…the gas tank. And you are regularly opening it and filling it and slopping a little gas around. If one was serious about a portable tank there are safe and elegant solutions. Perhaps similar to those tanks for gas powered boat engines. The tank has a dispensing nozzle and hand pump instead of tilting and lifting the tank.
          Anyway, the gas tank is undersized in order to qualify for California HOV lane use. I am not sure that everyone realizes that is why it is so small. Surely there is an aftermarket add on for the BMW i3 tank.

          • You can “code” the car to enable more of the tank. Though, that might well nullify your warranty.

          • Carrying gas around in n automotive gasoline tank with emission controls and ventilation is far different than carrying a 1-gallon can of lawnmower fuel in a tin can under your hatchback.

            I was talking more of the latter than the former based on childhood/teenaged experiences.

          • “the gas tank is undersized in order to qualify for California HOV lane use. ”

            There are a total of 7 vehicle that qualify while still having gas tanks. The volt has a 8 gallon gas tank. The fordC-Max has a 13 gallon gas tank. The BMW by far has the smallest gas tank. HOOV stikers are not the reason for the small tank.

    • Stale gas is not a problem if your gas tank is totally sealed. Some of the components of gasoline evaporate easily. Others don’t . If you let gas evaporate the portion that doesn’t evaporate looks a lot like motor oil instead of gas.

      Most cars have gas tanks that that allow some vapor out on a hot day. So if you don’t drive the car for a while the gas will go stale. However some cars like the volt have a special gas tank that is totally sealed After getting my volt the GM supplied gas lasted 6 months before I used it up on a long drive. The was no problem with the gas or engine.

  • How about a trip from Las Vegas, NV to Green River UT? It is only 406 miles. I think there would be a significant problem once you get past Salina UT on the way to Green River.

    • There are plenty of trips it wouldn’t be appropriate for. I wouldn’t climb Pikes Peak with it either! Horses for courses!

      • I think this recent year’s Pike’s Peak race was won by an electric car. Were there two of them? (EVs)

    • There are plenty of parts of the US where there are no people or gas stations.
      That’s why the Wright Brothers perfected the airplane.
      Or you could just use a Volt to cover that distance, if you can find a dealer willing to sell you one.

      • The Wright brothers’ plane was good but not perfect. I waited for Boeing to try making one. WB Air didn’t have coffee, stuff like that.

  • Zachary reported that some people get the larger Euro fuel tank installed as an aftermarket hack. Other hacks to the software are available to give the same functionality as the Euro versions. Of course you can also carry a container of gasoline in the car to further alleviate concerns about running out of fuel.

    • Such modifications are actually no legal in some places. IN Californai car are required to pass an emissions test every couple of years in order to get a licence renewal. Any changes to the engine or fuel system (if noticed ) would cause an instant no pass result

    • Yeah, Tom seems like a straight shooter and is a well known electric BMW pioneer (probably best known) who in some ways essentially “represents” the company (maybe not formally, but certainly informally, and certainly as a moderator of The Official BMW i3 Forum). I don’t think he would engage in such activity. But he can respond about that if he feels inclined.

      • I have not coded my car.

  • On the east coast of the US its easy to find a gas sation every 10 to 20 miles. However on the west coast and rocky mountains it is a very different story. For example highway 87 from weed California to Kalamath falls oregon there are no gas stations for 71 miles.Beyond Kalamath there are a few but you stil about 40 to 50 miles apart. If you want to drive to death valley don’t take the i3. Going from Yosemite valley to Tuolumne meadows you need enough gas to go 58 miles.

    The BMW decision to piut a 2 gallon gas tank in the car doesn’t make a lot of sense. There are a lot of companies making 10 callon gas tanks cars on the road today. And even a 5 gallon gas tank would not take up that much more space.

    Another thing not mentioned in this article is the the ICE in the i3 can barely provide enough power to drive at freeway speeds on level ground. People driving the i3 have reported the the car can barely manage 40 miles per hour on a hill on the freeway. In the US that is slow enough for the highway patrol to give you a ticket.

    • Depends on your needs. If you are on the East Coast, finding a gas station quickly generally isn’t an issue. If you don’t drive on the Interstate much and are fine driving ~70 mph when you do use it, it’s not really an issue. If you aren’t driving around the Appalachians (or bigger mountains further West), I don’t think it’s an issue.

      But, yes, the small gas tank was reportedly just to meet some CARB regulations… not best decision for the customer, and it is a black spot in BMW’s otherwise quite impressive electric initiatives, imho.

  • I read the link. I think her use case is typical for a person who does what she does for a living, but quite different from mine.

    I would use the car differently (short commute, no business driving to visit client sites except in very rare cases, charge at work) so as to not have the problems she mentioned.

    • The problem for the woman at the link to autoconnectedcar is that she couldn’t be bothered to plug the car in overnight at home! Sheesh. Even 110 volts will get a car mostly charged overnight.

Comments are closed.