WLTP, NEDC, EPA: which range figure tells the truth?

Three acronyms for one car, three different range figures. NEDC inflates the number by 25 to 30 %, WLTP has been the only approved standard in Belgium since September 2018, and the American EPA lands 10 to 25 % below it. On a 2017 Zoe resold here, the gap between the original brochure and a real Belgian January runs past 200 km.

One Renault Zoe, three range figures, 200 km apart

Renault sold the Zoe Z.E. 40 between October 2016 and September 2019 with 403 km on the spec sheet. That was NEDC. The same car, put through WLTP, drops to 300 km. And Renault's own technical sheet already quoted 300 km in summer, 200 km in winter.

One car. Three figures. A factor of two between the best and the worst.

That Zoe is still on the road and still sells well in Belgium, because it has become affordable. The classified ad, though, often repeats the original number, since that is what the 2017 paperwork said. A buyer counting on 400 km discovers 200 km on the first February run from Brussels to Namur, heating on, and wonders whether the battery is dead. It is not. He bought an obsolete standard along with the car.

What does the WLTP cycle actually measure?

A 23.25 km run on a rolling road, in 30 minutes, at an average of 46.5 km/h and a peak of 131.3 km/h, split into four phases of rising speed.

The WLTP procedure, introduced by European regulation 2017/1151, applies to every new car type-approved in Europe since September 2017 and to every new vehicle registered in Belgium since 1 September 2018, the date on which the country switched all of its new registrations over to this cycle. It measures consumption, emissions and, on an EV, range. Unlike NEDC, it accounts for the options actually fitted: 20-inch wheels and a panoramic roof pull down the approved figure for the exact version you order. The Belgian sector federation Febiac sets out the technical detail for this market.

The weak point jumps out as soon as you look at the average speed. Forty-six kilometres an hour is a suburban commute. A Belgian motorway at a constant 120 km/h appears nowhere in that cycle, which is the mechanical reason the gap widens far more on the E411 than on the Brussels ring. We measured that gap model by model: 25 to 35 % in summer, 35 to 45 % in loaded winter conditions.

NEDC, WLTP, EPA, CLTC: the four cycles side by side

Only one of those four columns carries legal weight in Belgium. The other three are decoding tools for everything else you read: a used-car ad, an American road test, a Chinese launch release.

Why does NEDC still linger on the Belgian used market?

Because a certificate of conformity cannot be rewritten.

Every car registered before September 2018 carries an NEDC figure on its paperwork, and that figure follows it to the scrapyard. On new cars, manufacturers have published the WLTP value since 2021, with a correlated NEDC 2.0 value tolerated for a while on certain type-approval forms. On used cars, nothing was ever converted.

Four reflexes in front of a Belgian ad:

• Check the date of first registration first. Before September 2018, assume the advertised range is NEDC, even where the seller says nothing about it.
• Take a quarter off the NEDC figure to get the WLTP equivalent, then apply your own driving conditions to that second number, never to the first.
• Be wary of round range figures. 400 km, 500 km: approved values rarely land on a round number, and a figure that smooth is usually a marketing figure.
• Ask for the certificate of conformity. It carries the official value and the standard used, which no photo in an ad will ever do.

WLTP consumption is measured at the socket, not at the battery

Here is the detail almost nobody knows, and it costs money every month.

The WLTP consumption of an EV, expressed in Wh/km or kWh/100 km, is the energy recharged from the mains. The protocol drains the battery over the cycle, then recharges it, and that recharge is what gets counted. Conversion losses are therefore inside the figure.

Your dashboard figure is built differently. The car counts the energy leaving the battery, and charging losses do not appear there.

Two figures, two measuring points.

Between them sit 7 to 12 % of the energy, depending on temperature and charging power: more on a slow domestic socket than on a wallbox, more in February than in July. The driver proudly comparing a displayed 15.2 kWh/100 km with the 16.8 in the brochure is not beating WLTP. He is comparing two measurements that do not start from the same place.

The gap can be checked at home, with no special equipment. Note what your wallbox or your meter billed over one complete session, then compare it with the number of kilowatt-hours the car says it received during that same session. The difference is your real loss rate, and it is worth knowing before you build a budget on the dashboard figure. On a domestic socket in the depths of winter I have recorded more than 13 %, simply because a slow charge keeps the car's electronics and battery conditioning running for hours on a trickle of current.

What do charging losses cost in Belgium?

Between 67 and 124 euros a year, depending on the region and the charging setup.

Take a compact EV showing 16.0 kWh/100 km on the dashboard, over 15,000 km a year. That comes to 2,400 kWh leaving the battery. Putting them in there means pulling more than that from the grid, and the difference is paid for without ever showing up on a dashboard screen.

Domestic price ceilings published by the CREG, the Belgian energy regulator, for the third quarter of 2026. Our own calculation over 15,000 km at 16.0 kWh/100 km on the dashboard.

A Walloon household charging from a domestic socket in winter pays 123.82 euros of electricity that never reaches the wheels. A Flemish household on a wallbox in summer pays 67.24. Fifty-six euros apart, for the same car and the same kilometres, on a line of the bill nobody reads.

So budget your electricity from the WLTP consumption figure rather than the dashboard one. The distinction between a kW and a kWh is one thing. Where the kWh gets measured is another, and that one shows up at the end of the month.

Should you look at EPA or CLTC before buying here?

EPA, yes, where it exists. CLTC, never.

The American agency tests across several cycles, including a cold start and a cycle with air conditioning, then applies a 0.7 correction factor to the raw result. The number that comes out is deliberately pessimistic, and that is what makes it useful. On models sold on both sides of the Atlantic, a Tesla or a Mustang Mach-E, treat the EPA figure as your Belgian motorway range and you will rarely be disappointed.

The Chinese CLTC travels the other way. Top speed 114 km/h, average 29 km/h, frequent stops that favour regeneration, a cycle cut for urban congestion: range comes out 25 to 35 % above what EPA would announce.

The figure is not false. It simply circulates too early. Chinese brands now established in Belgium communicate in CLTC months ahead of European type approval, the press repeats it, and by the time the car reaches the dealership the range has shed a third without anyone having lied.

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