Toyota bZ4X review:

Toyota bZ4X range disappoints

Never before have we felt the need to redo all tests to confirm our results. Toyota has answered our criticism.

Toyota bZ4X: Toyota's new electric car has many good sides, which unfortunately is shadowed by some big disappointments. Photo: Fred Magne Skillebæk
Toyota bZ4X: Toyota's new electric car has many good sides, which unfortunately is shadowed by some big disappointments. Photo: Fred Magne Skillebæk Vis mer

(Elbil24): Updated: Toyota has commented on our findings – see their response here:

This test is of a newcomer to the Norwegian electric car market, one that is sliding straight into our biggest segment, in which we can find the greatest number of buyers.

In Norway alone, a large number of patient customers are waiting to receive their cars. The early birds are already driving it.

This test is about a car that is solid in a number of areas, but that greatly underperforms where it matters most.

This is because the Toyota bZ4X underperforms on consumption, on range, on usable battery capacity, and on what we can call honesty – its ability to follow through on the promises Toyota has made for the car.

A first

The Toyota bZ4X is the brand's very first modern electric car, and the first real foray from one of the world's very biggest car makers.

This model was meant to be launched in July, but it was abruptly banned from the roads. The reason for this was that the wheel bolts had a risk of loosening, with the subsequent risk that the wheels could fall off as well.

It’s now finally ready to drive, and we’ve run the car through our thorough tests, which also includes our 100-0% range test, our consumption test, as well as our 0-100% charging test.

I can reveal that this is the first time we’ve had to run our tests multiple times, as we were scarcely able to believe the first results we got.

Toyota bZ4X range disappoints

Theoretical range

Toyota promises that the four-wheel drive edition of the bZ4X will have a range of 470 kilometres, going by the standardised WLTP test.

If you drive the front-wheel drive edition, the powertrain should be even more efficient, bringing you up to a total of 516 kilometres under equivalent conditions to the WLTP test.

We can immediately make it clear that you will never be able to achieve this in a bZ4X, if all the cars that are being launched are of the same make as our testing model.

There are a number of practical reasons for this, and we have viewed it as being necessary to perform the tests repeatedly to confirm the results.

Battery capacity

Range is always a factor of two properties in particular – consumption and available energy volume.

Toyota has, for a longer period of time, communicated that the battery capacity of the bZ4X is 71.4 kWh, but we have on several occasions been told that this is the net usable capacity. We have also requested the gross capacity, only to learn that they do not wish to communicate this to us.

At a Lexus event, we were nonetheless told by engineers, who presumably had not been drilled on what to communicate, that the gross battery capacity is 74 kWh.

Since then, Toyota has denied this, claiming that 71.4 kWh is the gross capacity, not net. After this, they have been unwilling to communicate net battery capacity, that is, the usable capacity – the part you can actually use.

But this is in fact the easiest issue to determine, as the only thing we need to do is to completely empty the car, then charge it back up and see how much energy was transferred into the car.

We've done this task twice. The first time, we fully charged the battery using AC charging (charging at home), and the second time using DC charging (quick charging). On both occasions, we ended up with a final result of 62 kWh.

As we weren't using anything that drained the power, and the ambient temperature was neither notably cold nor hot, there should not have been any reason to expect a major loss of charge for battery conditioning.

In both cases, the battery was run to its capacity (0 km range remaining), and set to charge. It therefore ran at a normal operating temperature, and we can assume that the net usable battery capacity is at 60 kWh when the marginal 2 kWh loss of charge is deducted. We find it difficult to believe Toyota's claim that the gross battery capacity is 71.4 kWh, when our tests show net capacity as low as 60 kWh. This is quite a major leap, to put it mildly, and it results in some major issues for the other tests.

Toyota bZ4X range disappoints


Let’s start with the range, which is given as 470 kilometres following the WLTP standard. WLTP tests are conducted using an established standard that continues for 30 minutes, which must be considered a short period of time. The tests must be done at 23 degrees Celsius, and the use of air conditioning or other power drains is not required. The manufacturers are also free to choose the tyre size they want, provided they select a size that is included among the options in the type approval. When it comes to tyre type and air pressure, the manufacturers can do what they want.

The tests are monitored by an independent third party. Once the testing has been completed, this party must verify that the testing was done by the book, or legally, if you will.

For electric cars, we have a lot of new parameters that serve as variable factors, including software, and how this is set up. However, the installation of custom software that may affect the official tests is not recommended, as Volkswagen was painfully reminded of in the so-called Dieselgate scandal. In other words, the cars should be as they are when the customer receives them. However, this is getting harder and harder to control.

Our tests

Our range testing follows a preset pattern, in which 25 percent of the route is on the highway, 70 percent is on country roads, and 5 percent is driven in a city area.

We always run through the entire battery in one go, meaning that the cars only have one cold start throughout the process, generally on departure. We start and end at the same place, and so there are no variables due to changes in altitude. In other words, we drive uphill just as much as we drive downhill.

The cars are always charged to 100 percent before departure, and we always drive the cars until the instruments say 0 percent / 0 kilometres left.

For modern electric cars, this is often a full-day job, depending on battery capacity and range.

We then charge the cars all the way up to 100 percent and read off how much energy is returned to the battery to get back to the starting point of 100 percent.

The amount of power used to recharge the battery then makes up the volume we spent on driving the many kilometres we've driven.

Toyota bZ4X range disappoints


As noted, we ran the test twice to make sure that we didn't make any mistakes. This is despite the fact that the testing procedure is bullet proof.

By default, we always have the radio or music playing and we always set the temperature to 20 degrees. In some cars, we can adjust the temperature up to 22 degrees, in case it will be unpleasant to keep going at only 20 degrees. Not all cars are as well-calibrated in terms of temperature information.

We always run the vehicle in “Normal”, not using the “ECO” driving programme. We do this because some cars reduce the performance of the air conditioning in the ECO position, and you will be unable to bring the car to a comfortable temperature during the winter. Aside from this, the ECO position is largely just a way to reduce the output of the gas pedal, and is primarily intended to help inexperienced drivers avoid excessive acceleration. An experienced driver gains very little from using this button, and in the bZ4X, it is not estimated to improve your range, either.

Toyota has, however, opted to give the ECO system its own button and function. This leaves you with only a changed gas pedal response when using the ECO driving programme.

Mysteries of the air conditioner

We are now approaching the core of the bZ4X's challenges, as with a fully charged battery, the instruments promised us a range of 407 kilometres before we left. This deviates significantly from the 470 kilometres promised by Toyota, but from experience, we know that this naturally also depends on how the previous driver operated the car. By their very nature, test cars are rarely driven gently.

However, we were in for a shock as we set up the 20 degrees we wanted in the passenger compartment. The range then fell sharply from 407 to 297 kilometres, a nearly unthinkable reduction in exchange for keeping the car a little warmer. We adjusted the settings for a while and found that 407 kilometres was only available when absolutely all heating was switched off, including the fan. Simply increasing the fan strength by one notch gave a ridiculous drop in range. It was admittedly possible to heat up the steering wheel and seat without reduction, but this is not enough.

CONSOLE: This is how the console for the air conditioning looks. NOTE. This photo was not taken during the test itself, cf. the degrees. Photo: Fred Magne Skillebæk
CONSOLE: This is how the console for the air conditioning looks. NOTE. This photo was not taken during the test itself, cf. the degrees. Photo: Fred Magne Skillebæk Vis mer

In a case like this, it’s easy to imagine that this is simply a wrongly calibrated range calculation. As the bZ4X has its own ECO button for the air conditioning, we chose to use this alongside the Auto-programme for the air conditioning. The ECO button reduced the range loss to 314 kilometres, but we were at least able to maintain 20 degrees Celsius within the passenger compartment during the test. After all, it was only 8 degrees outside, a temperature that simply is not suitable to have in a car over the course of a whole workday.

Actual range

To cut a long drive very short, we finally rolled up to the charger with 0 kilometres of range remaining, which we must assume is also 0 percent, as the car itself does not display percentages. This feature is sorely missed for experienced electric car drivers.

The section that indicated how far we had driven stated that we had travelled 307 kilometres from where we started, while the consumption gauge showed that we’d used 19.1 kWh/100 km.

From experience, having tested the range of new electric cars that are currently on the market, this consumption is much too high, and the distance is particularly short – especially considering that the stated range is 470 kilometres. It should be noted that the terrain was wet, and it was rainy. The car was also using 18-inch winter tyres. However, none of these factors come anywhere close to wiping out this much range.

Driving the car for a few hundred kilometres without putting the fan on even the first notch is also far from an option.

We were struck with the thought that we may have done something wrong, and to be sure, we performed the test again, a few days later. The next test was in clear weather and dry terrain, but the same recipe and procedure was otherwise followed.

On our second try, the range increased to 318 kilometres, a natural increase considering the change to the terrain. Despite this, the car's instruments showed the same consumption as earlier in the week, 19.1 kWh per 100 km.

CABLE BAG: Large, but practical. You can also store cables beneath the top floor board in the trunk. Foto: Fred Magne Skillebæk
CABLE BAG: Large, but practical. You can also store cables beneath the top floor board in the trunk. Foto: Fred Magne Skillebæk Vis mer

Actual consumption

Before we continue, it is important to clarify that the stated specifications from Toyota and the WLTP tests are determined for 23 degrees Celsius. This is a nearly ideal temperature for an electric car, as this temperature is at the exact point where the it's not so hot that the battery needs to be cooled off, nor so cold that it must be heated up. Under such ideal temperatures, the stated consumption from Toyota should be 15.8 kWh/100 km, according to the WLTP tests.

We tested the car at 8 degrees Celsius, a temperature that is still at a reasonable level for electric cars. For reference, I note that the batteries in electric cars are heated to 8-10 degrees Celsius for driving during the winter.

But what about our tested consumption? As mentioned, at the end of the ride, the instruments showed a consumption of 19.1 kWh per 100 km, but this is also the lowest consumption in the entire trip, because the consumption after starting was much, much higher. Consumption then gradually reduces as the temperature of the battery and the powertrain increases. According to the car, it ended up at 19.1 kWh/100 km.

The most reliable source for actual consumption could nonetheless be found in dividing the consumed energy volume by the number of kilometres driven. This also includes all charging loss, regardless of size.

When we know that we recharged the car using 62 kWh energy after driving 318 kilometres, the calculator shows that we have an actual consumption of 19.5 kWh per 100 kilometers.

407 KM: We were promised a range of 407 km, but after eighty kilometres with the heating off, it became clear that this wouldn't be possible either. Photo: Fred Magne Skillebæk
407 KM: We were promised a range of 407 km, but after eighty kilometres with the heating off, it became clear that this wouldn't be possible either. Photo: Fred Magne Skillebæk Vis mer

This is actually quite spot-on for Toyota, because the discrepancy between stated consumption and actual consumption tends to be much higher. We’ve actually been up to 20 percent deviation for these figures in a few cases, and in both cases, the cars were from the same maker, just different models.

The unattainable

The energy consumption actually isn't the worst result in this test. We can actually live with the range too, because how often do you drive further than 320 kilometres in a day?

Pretty much the entire challenge of the Toyota bZ4X lies in what Toyota refuses to tell us, what they want to keep hidden – the net usable battery capacity.

Since it is no higher than 60 kWh, you will absolutely never reach 470 kilometres in a bZ4X. Not even on a sunny summer day, and remember what I wrote previously in this article.

Consumption in WLPT tests is measured over 30 minutes, not a full battery cycle as we've done.

I therefore find it odd that Toyota has been able to market the bZ4X as having a range of 470 kilometres for the four-wheel drive edition, and the 516 kilometres for the front-wheel drive edition stranger still.

If we had had the full capacity of 71.4 kWh as usable capacity, this would not have been enough for more than 450 kilometres considering Toyota’s own stated consumption of 15.8 kWh/100 km. Sure, a few kW would have gone back to the battery through regeneration, but not nearly enough wattage to justify these figures. This is simple math.

Toyota bZ4X range disappoints

A cold winter's day

Our tests were conducted at 8 degrees Celsius. The batteries of the bZ4X are composed of 96 cells with well-known technology and chemistry, lithium-ion-based, and the chemical composition of such batteries do not like the cold.

This increases the internal resistance, which results in a reduction of voltage in the battery cells, and a reduced capacity. Yes, indeed. This capacity increases when the cells heat up again, but the vicious circle during the winter causes energy to be used to generate this heat. The end result is that we always end up with a shorter range during the winter compared to the summer.

What then for the Toyota bZ4X, which delivers just over three hundred kilometres on a foggy autumn day?

To go into detail about this, we must consider how the car behaves during charging. At the moment, the bZ4X should be able to handle 6.6 kW through AC charging, the type of charging we do from home. Later, they will allow an onboard charger with 11 kW.

During quick charging (DC charging), it will be able to receive 150 kW. However, it will be the same for Toyota as everyone else. The stated maximum wattage will at best only be reached for a brief moment, and then only during optimal conditions.

As usual, we've completed our 0-100% charging tests, in which we start the charging sequence with 0 km / 0%, in other words, a battery that is almost completely empty. We then charge it all the way up to 100 percent full charge. We log all wattages, timings, and capacities.

For the bZ4X, everything was painless between 0 and 80 percent. We reached, as the graph says, a maximum wattage of 112 kW with 30 percent SoC (State of Charge) before slowly but surely dropping off. The fact that we didn’t reach a higher wattage was because the battery was nowhere near the optimal temperature needed for this.

80 percent SoC was reached after 39 minutes, with a wattage of 35 kW. The 10-80 percent range took 35 minutes to fill. Had this been a 71 kWh battery, this would be excellent. It's good for a 60 kWh battery too, although naturally not good.

Then there’s the coming winter. As we now know that 100 percent SoC on the bZ4X comprises 60 kWh, and that this means a range of 320 kilometres, we know that this will be significantly shorter when cold winter days come. It's certainly not unthinkable that this may drop as low as 280 kilometres, and we're still talking about 100 to 0 percent.

If you for clear and natural reasons have not quick charged the car further than to 80 percent, then you're already down to just 220 kilometres.

Now, we must give the subject of this article the benefit of the doubt, but it is unfortunately the case that there are no electric cars on the market that have been able to counteract the laws of physics during the winter, so this seems like a realistic expectation.

Driving with no heater and no fan on is not a solution either. This would impact safety.

The illness therefore only has one cure, and only Toyota can administer it. They must expand the net capacity of the battery. There is a lot of room to improve with a buffer of just 10 kWh, and they must do so now.

Anything else would be to toy with their customers’ patience, which has already been tested through the issue with the wheel bolts.

From the beginning, Toyota has set as a goal that it will offer long warranties on the batteries. With different campaigns, you can get warranties for the car ensuring up to 90 percent remaining capacity at an age of ten years. The question is whether you want a car you can live with for these years, or if you want to protect yourself from year ten and out.

Toyota must also take into account that they are in competition, and that they are not alone in delivering electrical cars to this segment. A number of future comparisons of competitiors will sho this.

Elbil24 has on several occasions spoken with the creators of the Toyota bZ4X. That was before we conducted this test, but in December, yours truly is heading to Brussels to talk to many of them again. The test results and experiences will naturally be a topic of discussion.

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