BMW i3s REX review

Having really liked the BMW i3, I was looking forward to testing the i3s as soon as it had been booked in. Featuring everything good about BMW's compact EV, but with a little more focus on a sharper driving experience, the i3s looked - on paper at least - as though it was going to be both an interesting and fun car to drive. So what is the first (mildly) hot-EV like to drive? NGC finds out with the BMW i3s REX.

Review by Chris Lilly


The use of 'mildly' above is a considered one, since the i3s is no hot-hatch by modern standards. A 0-62mph time of 7.7 seconds for the i3s REX could be described as nippy rather than fast, but it's more than quick enough for most drivers. As with all EVs, it feels faster than the figures suggest because of the impressive pick-up from standstill. With 183 hp and 270 Nm of torque - up from the i3's 170 hp and 250 Nm - the i3s has plenty on offer to keep enthusiastic drivers happy. A single-speed transmission makes accessing that performance easy, with just a stomp of the right foot all that's needed to leap off the line like the proverbial scalded moggie. Where the added power becomes noticeable is not at the lower end of the speed spectrum, but as you push to 60 mph and beyond. Here, the extra brawn from the i3s over the i3 makes itself felt, as the former is a little more comfortable cruising at motorway speeds than the latter. It's only a slight improvement, but it helps make the electric BMW happier in its role as a commuter car on the motorway. When it comes to bringing that speed into check again, the BMW has plenty of stopping power, thanks in part to the relatively light kerb weight. It's strong brake energy recuperation system though is the main factor, grabbing otherwise wasted electrons as soon as the driver lifts off the throttle, and shoving them back into the battery. 'One-pedal' driving is easily possible in the i3s with forethought; the only time you really need to touch the brake pedal is when starting the car up and then when parking up again - though using the brake pedal is often easier. Unlike Nissan's ePedal system, you can't turn the strong brake regen off, but it's something that drivers quickly adjust to.


A key reason for the i3s existing is that it is intended to be a better handling car than its non-'s' stablemate. With a wider track - the i3s is 16mm wider than the i3 - the BMW is able to be fitted with slightly wider tyres. This means there is more grip and a lower centre of gravity; good things to hear for a car looking to offer a sharper driving experience. What it means in the real-world is that the i3s is certainly a better car to drive than before. The standard i3 is a good little supermini, with a stiff but not-unduly-so ride, and precise handling. The i3s improves a little on each of these attributes, with sharp and accurate turn-in, a good weight to the steering, and suspension that keeps things level while cornering - the added width improving agility. I loved throwing the i3s around a country road, even though its natural habitat is a built up area. It excels in both situations, making the most of its small footprint in particular around town. Car parks and tight junctions are tackled with aplomb, and the i3s is not too stiffly set up to make pot holes and speed bumps a major inconvenience - not any more so than normal anyway. On the motorway or dual carriageway, the i3s disguises its lack of length pretty well, and settles down nicely. It's not a natural long-distance car simply because of its overall size, but the BMW felt fine to drive over long distances without any feeling that I was in the wrong car for the job.


The i3 and i3s are always going to divide opinion. The futuristic looks set them apart from the rest of the supermini market - with the styling making it stand out no matter what powertrain you are considering. Personally I like the design. It's not perfect, and can be a little overly fussy, but the overall impression is a positive one for me. And the i3s is better than the i3. That extra width means the wheel arches have been flared a little to hold the wider tyres. All of this helps drop the i3s visually, creating a car that looks wider and - more importantly - less tall. The i3 can look a bit narrow, emphasising its height, where the i3s - particularly with its more aggressive front bumper design - looks a tad more sporty. No bad thing in my book.

Moving away from personal opinion though, the i3s REX retains the i3's interior space. Access to the rear seats is via the short, rear-hinged doors, only usable once the front doors are open. Although not as flexible as a full five-door hatch, the rear-hinged doors allow for easier access to the back seats. For those fixing in little 'uns, this is a real benefit, and makes completing said job less of a yoga challenge than usual. Rear leg and head space is reasonable rather than ample, and tall adults will want to keep long distances to a minimum. Throw a couple of children in the rear though, and there are no such problems. The i3 in all four iterations - i3, i3 REX, i3s, and i3s REX - is a four-seater. Boot space is not large either, and in fact a little smaller than you will tend to find in the supermini class. It's still capacious enough for a supermarket shop or a few overnight bags, but a family camping trip with kit is not going to happen without the need for a roof box/trailer. Keep rear occupants of a compact size, and the use of that boot space to daily chores though, and the i3s does fine. Up front, there are no such issues to consider. There is a great feeling of spaciousness, even for a relatively narrow car, and the front occupants will feel comfortable. There's not a lot of storage space, but enough for a mobile phone or two, and some drinks bottles etc.


BMW i3s REX interior

Moving away from interior space, the cabin as a whole is an excellent one. The cleanly designed dashboard wouldn't look out of place in an up-market Scandinavian apartment let alone a car, and it's a principle that works well too. The driving position is easy to set up just so, and the simple steering wheel has only a few controls on it. The gear selector is positioned behind the wheel, falling easily to the driver's right hand. This frees up space in the centre of the car for a bit of storage, and controls for the infotainment system and driver modes. The only other buttons are nicely arranged on the upper edge of the dash to control heating and media settings, sitting a little below but ahead of the central information screen. There is a handy shelf here to throw bits and pieces on - wallet or phone for example - and the wide screen is of excellent quality. Crisp graphics and fast to react to commands, BMW's infotainment system works well here. The driver also has a small screen in front of them for driving information, replacing a traditional binnacle. The whole effect means the minimalist dashboard is practical and allows for excellent forward visibility. The seats are comfortable - even for long trips - and the whole cabin is well designed, with controls falling easily to hand throughout.


The i3s REX is the least efficient of the four BMW i3 models, but it still scores excellent marks for fuel economy. BMW is currently the only manufacturer offering a mass-market range-extended EV in the UK, which remains puzzling. As an EV-biased middle ground between conventional EVs and PHEVs, there are a large number of drivers who would appreciate the back-up of an on-board generator to boost an EV's range for occasional longer trips. The BMW i3 REX has CO2 emissions of 13 or 14 g/km - depending on specification - while the i3s REX has an official CO2 figure of 15 g/km. Technically not as efficient then, but only by tiny margins. The main reason for this is because of the wider tyres. Obviously the pure-electric i3 and i3s produce zero tailpipe emissions. The quoted i3s REX range is 137 miles on the NEDC tests from a single charge. This is also calculated under the more accurate WLTP protocol at 115 to 121 miles. Using a 38hp two cylinder petrol engine, the i3s REX can add an additional 93 miles of range when used.

After more than 500 miles in my care, the on-board computer was quoting 118 miles of EV range from a single charge in standard Comfort mode, 120 miles in Eco Pro mode, and 129 miles in Eco Pro+ mode. This was after a wide range of trips and driving styles, so that figure should be a pretty accurate reflection of what is possible for most drivers. Weather conditions were cool but not cold, and it rained for about half of my time with the BMW. The maximum range the REX said it would add was 123 miles, but that averaged out to 85 miles in Comfort by the end of the loan. Therefore, a realistic and easy to achieve real-world combined EV+REX range of 200 miles is reasonable to expect - without any great effort for economical driving. I have to say that I got to the last day of my week with the i3s REX and hadn't used the engine at all, such was the usability of the EV range. There was a day when more than 160 miles were covered, but some simple EV destination top-ups - where I was having to stop anyway - made the use of the engine unnecessary. It was good to know that the engine was there anyway, able to kick in and charge the battery if needed - the engine never powers the wheels directly. The engine can only be activated once the battery's charge is below 75% and, when running, it is noticeable but not intrusive.


BMW i3s REX charging

There are a number of green car features incorporated into the BMW i3 range. Much of the car is made from extremely stiff but lightweight carbon fibre reinforced plastic, while a large amount of the interior is built from natural materials and recycled plastics. BMW says that more than 80% of the surfaces visible are made from recycled materials or from renewable resources. As mentioned, the i3s REX has different driver modes, including Eco Pro and Eco Pro+. These restrict throttle response and the drain from auxiliary systems to help maximise range. As is common with EVs, connectivity helps make life more efficient too. The BMW i ConnectedDrive system allows drivers to check state of charge, set charging times, and pre-condition the car to save the i3 from having to heat a large space using battery power. The i3 range can charge at up to 11 kW too, dramatically reducing the time it takes to fast charge the 33 kWh battery - 28 kWh of which is usable. Charging is carried out via the CCS inlet, with Type 2 for slow and fast charging, and the full CCS for rapid. BMW quotes energy efficiency at 12.5 kWh/100km under the NEDC tests. My worst figure was 3.3 miles/kWh (18.8 kWh/100km) - a projected real-world 92 miles of EV range - and best average score was 4.4 miles/kWh (14.2 kWh/100km) - a projected 123 miles of real-world EV range. According to our calculations, the model tested has a Next Green Car Rating of 24.


The BMW i3s REX is pricey, so it's a good job that it comes with a decently long list of standard equipment. The i3 range is divided into four trims - Atelier, Loft, Lodge, and Suite - that change the look of the cabin more than the specification really. Included in the standard kit are 19-inch alloys, BMW Professional navigation system with DAB, Bluetooth, and USB connectivity, LED headlights, BMW ConnectedDrive services, multi-function steering wheel, and rear parking sensors. Standard on the i3s models are 20 inch alloys, higher power motor and tuned handling, Sport mode added to the driver profiles, and sports suspension (10mm lower). There is a comprehensive list of options available though, which turned the £35,625 base i3s REX model tested (inc Cat 1 Plug-in Car Grant) into a £41,435 car (also inc. PiCG). These options included different 20-inch alloys, (excellent) Harman Kardon audio system, reversing camera, parking sensors front and rear, Apple CarPlay preparation, Traffic Jam Assist, and privacy glass. That's based on the Suite 'interior world'.


BMW i3s REX rear

The BMW i3s REX is fairly expensive and not as practical as its EV rivals. That said, I still think it's brilliant. The driving experience is beyond what any other EV below £50,000 can offer, and there's a sense of fun to the i3s that few other cars can match - electric or otherwise. Yes, there are quicker models out there, and better handling cars outright, but the i3s can be thrown about perfectly safely and within legal limits with a big smile on the driver's face. On a more sensible note, the i3s REX does everything that a supermini should, and does it really well. It's easy to drive in built up areas, and comfortable at pace too. There's space inside for four and the boot will take a few bags without issue. Almost all trips can be completed in on electric power too, with more than 100 miles of range in all but the worst conditions easy to rely on. The usefulness of that range was proven to me when I had to actively switch the REX part of the i3s on, and with a combined range of around 200 miles - plus quick top-ups of fuel adding another 80 miles or so each time - there is no reason for anyone with a petrol or diesel supermini to complain about the i3s REX's relative lack of range. It's a fantastic car, with only its price limiting it from the full five star rating in my point of view - instead it will have to settle for four and a half.

Model tested: BMW i3s REX
Body-style: Five-door supermini
Engine / CO2: 135 kW electric motor and 647cc petrol engine / 15 g/km
Trim grades: Atelier, Loft, Lodge, and Suite

BMW i3s REX on-road price: from £35,625. Price as tested £41,435 (both inc Cat 1 PiCG)
Warranty: Three year / unlimited mileage - Battery & drive unit: Eight year / 100,000 miles
In the showroom: Now
Review rating: 4.5 Stars

Click here for more info about this model range

Chris Lilly

Author:Chris Lilly
Date Updated:24th Jul 2018

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