Eco-Test Country loop - Audi A3 e-tron v BMW i3 v Citroen C4 Cactus v Toyota Prius-200

Audi A3 e-tron v BMW i3 v Citroen C4 Cactus v Toyota Prius: Economy comparison test part two

By now you’ve hopefully read part one of this economy comparison test, where we set out for 100 kilometres of urban driving.

The aim of part one was to find out which of the four cars on test – Audi A3 e-tron, BMW i3 range-extender, Citroen C4 Cactus and Toyota Prius – was the most efficient, city-friendly commuter. And the winner was clear.

But not everyone only drives around town. Sure, it could be argued that if you’ve got $70,000 to spend on a BMW i3 you’re probably going to have a couple of other BMWs or more open road-appropriate cars for highway journeys.

What if you don’t, though? The range-extender version of the i3 is clearly designed to offer some peace of mind with its claimed 300km driving range, which is 140km more than the regular EV model. We wouldn't have attempted this part of the test if we’d only had the EV.

Instead, we decided that the i3 would travel with a jerry can full of juice, just in case its claimed 300km range was too little to reach our destination. It should be noted that BMW previously offered i3 owners a conventional loan car for long-distance drives (that program has been cancelled), and we acknowledge we’re clearly operating outside of the vehicles intended parameters here…

For the highway segment of the trip we again set off from the CarAdvice office in Sydney, with the aim of heading on the highway down towards Australia’s current wind farm capital near Crookwell, outside Goulburn.

Specifically we were heading to Taralga, about 255km away from the office. So yeah, you could say we planned to cut it pretty fine in the i3. And we did…

Hitting the road:

As with the urban test, we topped up everything to its maximum capacity, though the i3’s charge system was proving sluggish. We’d put it on charge at 5:00 pm the day before, and with a generous start time of 9:00 am the following day we were shocked that it hadn’t completed its charge over 16 hours. That’s what BMW claims it should take as a maximum from empty, after all.

Upon further investigation, a previous user of the car had set the charge rate to be the most conservative, probably with the aim to draw less from their power supply.

There was no such issue with Audi A3, which was fully charged and ready for take-off, and all four vehicles were once again topped up to their respective filler brims with a jerry can to ensure we were at maximum capacity.

We wound up the charge cables, zeroed our trip computers and hit the road and aimed for our first stopping point (Partridge VC Rest Area) on the Hume Motorway past Campbelltown. This time around it was myself, Trent Nikolic, Curt Dupriez and CarAdvice lifestyle editor, Tegan Lawson.

In that first 73.5 kilometres we saw the Audi A3 e-tron’s electric range dissipate, followed by a smooth transition to hybrid/petrol power. The petrol-electric drivetrain was set in auto mode, which chose to use the batteries for the first stint of the trip and then use petrol power to help propel it at higher speeds.

The BMW i3 managed the first stint without hassle, easily managing the EV stint, but it became clear that the range calculations needed to be taken with something of a grain of salt. The figures for remaining total range, electric range and petrol range fluctuated pretty wildly, with the wind resistance (it gets blown around – A LOT) and traffic seemingly playing a part.

The Citroen C4 Cactus cruised along happily at highway speeds – no more of those gearbox gripes. It was relatively quiet, and the suspension was more settled on the open road than in urban confines.

The Toyota Prius also proved relatively happy on the motorway, but the wind noise from the mirrors and some road noise through the floor hampered the experience somewhat. At this point its EV driving ratio was about 40 per cent.

We kept moving from there, but took readings at the 100-kilometre mark on the leg down to Taralga, with the following results registered:

Audi A3 e-tron – 4.6 litres per 100km, <1km ev="" range="" remaining,="" 557km="" total="" remainingBMW i3 – 0.0 litres per 100km, 4km EV range remaining, 108km petrol range remaining, 112km total range remaining
Citroen C4 Cactus – 4.4 litres per 100km, 1001km total range remaining
Toyota Prius – 4.5 litres per 100km, 824km total range remaining

After a quick breakfast stop – and a top-up of our jerry can for the i3 (just in case!) – we kept heading south, but also up, into the Southern Highlands. It wasn’t long before the i3’s range-extender petrol engine kicked over, emitting a rattly burble from the rear of the car (that’s where the engine sits).

It worked to recoup some electric charge when it could – coasting down hills or when braking – and the EV range teetered between 1km and 20km.

The Audi’s EV range also managed to fluctuate, but not to the same extent. It hovered between <1km and="" 8km.<="" p="">

We then headed past Marulan and into Goulburn, where we hit the 200km mark.

Here’s how each car fared to that point:

Audi A3 e-tron – 4.4 litres per 100km, 2km EV range remaining, 574km total range remaining
BMW i3 – 0.0 litres per 100km (it doesn’t have a litres per 100km readout!), 3km EV range remaining, 89km petrol range remaining, 92km total range remaining
Citroen C4 Cactus – 4.2 litres per 100km, 1060km total range remaining
Toyota Prius – 4.4 litres per 100km, 772km total range remaining

Showing that the electric motor and batteries in the Prius aren’t made for highway driving, our EV driving ratio dipped to just 15 per cent to the 200km point.

The fact the i3 doesn’t have a readout for average fuel use means it’s somewhat difficult to fully monitor use, and with the displayed range remaining being so erratic, we found ourselves getting a bit nervous as we continued on.

The A3 was very much in petrol mode at this point, though again it was clever enough to judge when it needed to use engine power versus electric power. Nobody complained about their time in that car.

The Citroen, too, was so, so adept at this type of driving that although we were swapping regularly, our four drivers all seemed happiest in the diesel Frenchie.

We arrived at our final destination – a wind farm just outside Taralga, because this was about showing alternative forms of energy other than the old oil refinery in Kurnell – where we aimed to get as many great photos as we could.

That saw the i3 run out its petrol tank, with 0km of range remaining, and it only had 5km of electric range remaining – and we were 4km outside town.

We made it back to town, where we topped up all four cars with fossil fuels, which was a bit sad given the eco-conscious area in which we found ourselves. But hey, no-one was putting their hand up to spend the night in Taralga with the i3 on a slow charge…

The good bit about spending highway hours in each car was that we managed to get a better impression of quality and comfort, not to mention interior convenience.

Pretty much everyone was happy with the connectivity on offer in all four vehicles, with media systems possessing Bluetooth phone and audio streaming (for dem tunez), as well as USB charging, though some were wary of eating battery power to power a battery.

The Audi’s media system lacks a touchscreen, but makes up for it with a rotary dial MMI Touchpad controller, so you can scribble in your location when using the navigation unit.

The touchscreen in the Citroen was a little less impressive, proving a little slow to react, and at times taking a moment to boot up from a stop. Indeed, on several occasions it had to think about what happened next, particularly when reversing. Oh, and with just one shallow cupholder, the Citroen loses the highway hydration test.

The Toyota’s screen was quicker to react and clearer to look at, but its menus were a bit difficult to navigate.

The BMW's iDrive media controller is excellent - the pick of this bunch for usability, even though it, like the Audi, lacks a touchscreen - while the beautiful materials on the dashboard, including the wood veneer panels, make it feel more special inside than any other car here.

As for seat comfort – which is important if you’re spending hours behind the wheel – the Citroen ranked first, with the Toyota coming in second with its surprisingly large seats, and the BMW and Audi tying for third with their slightly firmer, smaller seats.

If you were to use any of these for a proper weekend-away style adventure, the BMW would be your last choice: its boot has just 260 litres of capacity, and there are only four seats. All the others have five seats, and bigger boots, though the Audi is only slightly better than the BMW, with 280L. The Citroen has 358L of cargo room, while the fourth-generation enlarged Prius has 502L of luggage space.

The Prius, though, is a little cramped in the back seat for headroom, while the i3 suffers limited knee room. The Citroen offers a nice compromise of leg and headroom, but shoulder room is tight (and you can’t wind down the rear windows!), while the A3 feels small but generally comfortable.

Here’s what our drivers thought about each car after jumping between the four en route to our windy destination.

Audi A3 e-tron

Matt Campbell:

The A3 e-tron is certainly more at home in the urban confines than on the open road, because that's where the electric part of the drivetrain comes into its own. Still there’s something very rewarding about zipping around using battery power, and it wasn’t embarrassed in this company when it came to open road economy, either.

Trent Nikolic:

The A3 e-tron will be the vehicle that is most palatable to most buyers. In reality, it’s the car that you could live with most easily – excluding the Citroen, which isn’t hybrid and is a lot less refined. You don’t have to plug in if you don’t want to, and it regenerates power on the move, which means it is capable at this sort of driving and the urban stuff, too. But it’s still a hybrid just for the sake of having a hybrid, and ….

Curt Dupriez:

It's just a normal driving experience and doesn't require any specialist attention on the open road. And it just replenishes its battery pack quickly and effortlessly on the move readying itself quickly for around-town EV duties. The problem is, it’s big money – I wonder how many millions of kilometres you’d have to cover to recoup the e-tron’s $25,990 premium at the filling station against a ($36,500 plus on roads) 1.4 TFSI Attraction variant. The cost-benefit is a tough one to sell.

Tegan Lawson:

As well as looking like a regular A3 it drives like one too, with few performance sacrifices of any note. It switches smoothly between driving modes, which can be manually selected or if you run the battery down the car will look after it. With a 40-litre tank there's less range-anxiety on the road, and over long distances it's a pleasant car to drive.

BMW i3

Matt Campbell:

This isn’t a roadtrip car. It shouldn’t be considered as such. But the fact is that if you’re prepared to plan your route and know your limits and the limits of the drivetrain, this could be suitable to most people’s needs. Just make sure you’ve also got another car in the garage for proper long-distance driving…

Trent Nikolic:

Problems start to arise once you leave the confines of the city in the i3. The petrol generator range (once the electric range is depleted) isn't enough to carry you properly long distances and it would lead to some white-knuckle range anxiety moments. I even had a few of those on the way back to Sydney after the test, where the drivetrain limited its performance up hills to dangerous levels: 80km/h on a freeway with a B-double up your date is not a comfortable experience.

Curt Dupriez:

I was highly sceptical as to if the i3’s combined ‘extended’ 300-kilometre maximum range could be achieved on the open road at highway cruising speeds. I’d presumed dialling up 110km/h on cruise control for long stints, without opportunity for braked energy recuperation, would push the battery system out of its ideal urban operating parameters and kill range potential. And it proved me very wrong indeed.

Why the modest nine-litre fuel tank to cap range-extension to just 150 kilometres? Because of marketing, as much as any other factor. Surely a longer range fuel-assisted than that on battery power alone would be an admission of defeat to the evils of internal combustion – range-extender or not – for BMW’s figurehead of electric mobility. I’d be tempted to do what some thrifty owners – Americans, I’ve heard – do, and retrofit a larger fuel tank: just another nine litres of fuel would push maximum range out to around 450kms… or 300km without the need to plug in.

Tegan Lawson:

With the jerry can providing peace of mind, it was fun to experiment using downhill runs and the intense regenerative braking to try and get the most out of the i3. At times the range would tick down worryingly fast, and then the next moment you'd be amazed at how slowly it was dropping.

At higher speeds the i3 feels very light on the road and is a prime target for the bullying crosswinds that plague stretches of the highway between Sydney and Goulburn.

Citroen C4 Cactus

Matt Campbell:

I would rather do a lap of Australia in the Citroen C4 Cactus than any of the other cars here. Not just because it had the highest remaining range available at the end of the day, but also due to the fact it felt more comfortable at highway speeds than any of the other cars on this test.

It’s kind of ironic – a car that is so blatantly designed for urban drivers feels most at home on the open road. If only Citroen had more dealerships out in the country, those buyers could have themselves a treat.

Trent Nikolic:

As the most efficient diesel on the market, the Cactus makes a lot of sense whether you spend all your time around town, or touring longer distances. The diesel works well in traffic or out on country roads, it's quiet, and barely ticks over on the highway.

The auto gearbox isn't perfect – particularly when you’re tooling around town –but with a cruising range of more than 1000km in the real world out on the highway, it is extremely practical for anyone wanting to travel longer distances.

Curt Dupriez:

A good chunk of the around town gripes with the Cactus's robotised manual transmission disappear on the open road. It's both easy to drive on the highway and offers all the punch you'd need for swiftly overtaking B-doubles.

Add the remarkable frugality – at its best on the open road – and slight soft-road leanings, it's really quite a desirable option for the regional buyer. As the utilitarian pick of the pack, from luggage space to cabin trim, it's one I'd choose to hit campsites or take to the weekend farm, hands down.

Tegan Lawson:

The diesel fuel efficiency is impressive. It was refreshing to get out of town, stop and check the range, and see that there's still more than 1000km worth of diesel in the tank. For someone like me that does a lot of driving from Sydney to Queensland and back, the Cactus would certainly save me some dollars.

Toyota Prius

Matt Campbell:

As with its fellow hybrid pals the Prius is not as at home on the open road as it is in the urban jungle, but there’s a certain ease of use that the Prius offers that its plug-in rivals don’t.

Now, don’t get me wrong. I think Toyota Australia has been a bit lame in its approach of not offering any plug-in hybrid versions of its cars in Australia, and there are definitely urban buyers that would love to have the Prius Prime instead of this version. But as a potential frugal family hauler, it’s not a bad thing whatsoever.

Trent Nikolic:

The Prius is only truly efficient around town. Once you hit the open highway, the Prius can't match the Cactus for example in terms of drivability or efficiency. It is a city-focused car, but still it wasn’t terrible on fuel in this test, and we know that you can rely on getting about 5.0L/100km even if you drive it hard.

It’s still hideous to look at, in my humble opinion, but I keep coming back to a more philosophical point: if there are non-hybrids that can get 5.0L/100km, why would you buy it over that sort of car?

Curt Dupriez:

As with its around town manner, the Prius feels heavy and a little laborious on the highway and country back roads. It's a comfy, if detached experience, and the strange feeling in the brakes (with its particularly regeneration methods) never goes away or improves with familiarisation.

It doesn't really make sense as a highway hauler because you get virtually no efficiency benefit from the powertrain, which is almost always in internal combustion mode, on the move. Its plug-in party trick is really meant for city driving. There's a long, long list of non-eco-savvy alternatives I'd rather drive cross-country that'd probably return similar frugality.

Tegan Lawson:

Even those who quite like designs that push the boundaries may find aspects of the Prius exterior styling eyebrow raising. The Lexus-like angles give it a futuristic look, however in my opinion the headlights look like they're melting down the face of the car and that grille is too narrow and small.

Inside it's comfortable and well equipped with the fourth-generation gaining new active safety technology. However, Toyota's hybrid technology hasn't moved as far forward as you would expect with this new generation, nine-years in the making, and the economy wasn't as frugal as expected either.

The lack of instrument cluster behind the steering wheel is a little unnerving at first but once you get used to it, the dual displays in the centre stack are easy to use on the run.


After a fair old stint if highway driving, we saw some intriguing numbers. Some lower than expected, and some not so much.

The BMW i3’s trip computer read 258.3km when we eventually refuelled (we purposely didn’t use the jerry can, though Trent did on the return leg back to Sydney). At that point, it had 1km of EV range and no fuel left.

Now, we know the BMW doesn’t have a fuel use readout, but we filled its 9.5-litre tank to the brim at the beginning of the trip and it took 9.35L at the end while showing empty (or $12.62 at a price of $1.35/L).

And if you do the maths, it used 3.6L/100km, plus the electricity use, which averaged at 16.3kWh/100km: figuring out the exact amount of electricity consumed is impossible, but it would have to be about $5.00 based on an average of $0.23 per kWh. So, an estimate would be about $17.00 for the trip.

The Prius’s trip computer read 257.3km and it used 4.7L/100km, with an electric driving ratio of 20 per cent – so, every fifth kilometre was driven using electricity, not petrol. It cost $16.11 to fill.

The Cactus didn’t have electric bits helping out, and while its trip meter read a little lower than the others (252km), it averaged 4.7L/100km on screen – identical to the Prius. It cost $14.21 to fill, but at a cost of just $1.18/L, as Taralga is not just wind-farming country, but actual farming, too.

The Audi, somewhat surprisingly, was the thirstiest on test. It used an average of 4.9L/100km, and with a fill cost of $18.63 – plus the cost of the electricity to fill its battery bank (8.8kWh – or approximately $2.00) – and the A3 is not just expensive to buy, but also the most expensive to run of these four.

Surprised? We were too.

But here’s the thing: when each of our testers was asked which car they’d take home – whether it was a runabout or a longer-distance tourer – the Audi was among the favourites. In fact, they all were.

Tegan Lawson (highway loop only, but spent time in all the cars around town, too):

Urgh... they all have issues. The i3 doesn't have enough range, the Cactus has that transmission, the A3 looks boring and the Prius’s dash layout is annoying. If I had to choose one for just long distance driving, it would be the Cactus, because the diesel range is impressive. But for my lifestyle, it would probably the i3 – because BMW offers a loan car for the times you want to go on longer drives.

Trent Nikolic:

For me it would be the i3 around town for sure, mainly because I would rarely ever need fuel. That said, it would have to be the Cactus if I had to do longer trips. The diesel range is perfect.

Curt Dupriez:

If I had to live with one of them, it would be the Audi A3 e-tron – hands down… Just so long as I don't have to pay for it!

Marcus Sroba (urban loop only):

I want to say I'd take the funky i3 but I park on the street so I wouldn’t be able to charge it at night. So I guess I'd take the e-tron. It’s pretty boring compared to the i3, but as I mentioned, it just seems like a normal A3, and it also seems like a better all-rounder.

Matt Campbell:

I travel a long way to work and back every day, and if I had to choose one, the Citroen C4 Cactus would be it. The potential to only have to fill up once a fortnight – rather than having to deal with plugs on a daily basis – not to mention the fact it costs less than half of some its rivals in this test means it meets, and exceeds, my criteria.

The general consensus, then is that the A3 feels normal, the i3 is a little bit too compromised as an all-round offering, the Cactus is a distance tourer par excellence, and the Prius … well, it’s still efficient, but no-one wanted to take it home.

Click the Photos tab above to see more images by Christian Barbeitos.

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