Winter testing: Pushing a Volvo EX30 to the limit in Swedish Lapland

How Electronic Stability Control has improved over the years

The obvious beneficiaries of winter testing are climate control and propulsion systems, along with the assessment of noise vibration and harshness. How materials age over time and in extreme conditions is also scrutinised.

But the largest area of improvement in recent years is software. Electronic stability control, or ESC, sometimes referred to as dynamic stability control (DSC) or electronic stability program (ESP), has been around in some form or other since the 1990s, and it has been a legal requirement on most UK cars since 2014. It works in conjunction with traction control and can mete out torque and brake individual wheels to keep you pointing the right way.

There are a variety of ways to test ESC, but Volvo still goes ahead with what’s known as the Moose/Elk Test (the Germans tend to use moose and the Swedish elk) because it’s quick and relatively easy for most drivers to perform, and it still gives a good impression of a car’s stability and controllability in slippery conditions.

In Sweden there are more than 60,000 vehicle incidents per year involving large animals such as moose, reindeer, deer and wild boar, hence the original need for the test.

Reassuringly, the Moose Test has been recognised by the International Organisation for Standardisation. It defines the test as ‘a closed-loop, severe lane-change manoeuvre for subjectively determining the obstacle avoidance performance of a vehicle, with slaloms of 10x18 metres and 10x36 metres’.

That description is just about as dry as you might expect from a standardisation authority based in Geneva, but in short it involves swerving to avoid a set of cones, then swerving again at speed in order to simulate an evasive manoeuvre.

It’s been going on since the 1970s, and we have been writing about it since the 1980s, but it hit the big time in the 1990s when a Swedish TV show flipped a Mercedes-Benz A-Class while performing it.

Cars have come a long way since then. And my own testing in Volvo’s EX30 proved to be wildly less spectacular. I have a video on my phone that I haven’t posted on social media because it just looks like I’m going around a series of corners.

John Lundegren, engineering manager for driving experience at Volvo, explains it: “Fundamentally, we continue to do the elk test because cars are changing at a rapid speed. ESC [has been] the biggest change in the past 20 or so years.

Early systems were fairly primitive, but now there are multiple variables with brakes, torque and other functions. They’re increasing year on year, and while ESC becomes more complicated, our testing needs to remain high.”

Winter range testing an electric car

Then there’s the switchover to electric propulsion. We all know the downsides to heavy, electric cars, not least their reduced cold-weather range.

Plummeting temperatures have a negative effect on an EV’s batteries because when the lithium ions move from anode to cathode, the cold slows the rate at which this can happen, which in turn restricts battery performance.

Range testing from our sibling title What Car? revealed that an XC40’s range plummeted by as much as 29.9% in cold weather testing compared with its warm-weather range. The Norwegian Automobile Federation found similar results.

Manufacturers have remained tight-lipped about these sorts of results – including Volvo. When pressed, a spokesperson said he was “unable to comment on the cold-weather performance of different Volvos”.

Why winter testing is so important

I park an EX30 outside of Lulea airport, get out and go to the boot to retrieve my luggage. The tailgate opens itself electronically after the press of a small button. Because of the cold, that button is covered by a thin layer of ice.

I poke through the frost with my thumb and press it lightly. It opens as normal. Then the penny drops: the importance of winter testing isn’t limited to dynamics.

Some goals of winter testing are measurable, but broadly they’re empirical: the cars need to work in extreme conditions.

Winter testing doesn’t sit nicely in one department’s yearly budget. It’s a holistic answer to countless questions, many of which are yet to be asked.

Where do winter testers go?

Arjeplog, Sweden

The big one: nearly all car manufacturers visit this Swedish municipality, situated 150 miles west of Lulea, for winter testing due to its consistently harsh and snow-filled weather. Some manufacturers, such as BMW, have permanent facilities there.

Wanaka, New Zealand

The Southern Hemisphere Proving Grounds in Wanaka offers winter testing from June to September and, unlike with Sweden, there are no frozen lakes: it’s all land-based. Tesla has tested its Models S, Model X, Model 3 and Model Y and Cybertruck here.