What Is WLTP Range? What the Number on the Advert Really Means

Look at any electric car advert and you will see a range figure: 250 miles, 300 miles, whatever it happens to be. That number almost always comes from a test called WLTP. It is useful, it is official, and it is not the number you will actually see on your own dashboard.

This is a short, plain guide to what WLTP range really is, why it exists, and why your real-world figure sits below it. If you are buying a used EV, understanding this one thing will save you a lot of disappointment on the drive home.

What WLTP actually stands for

WLTP is the Worldwide Harmonised Light Vehicles Test Procedure. It is the standard laboratory test used across the UK and Europe to measure how far a new car can travel on a charge, along with its efficiency figures.

The key word there is laboratory. WLTP is not a measurement of someone driving a car around Britain in normal traffic. It is a controlled test, run under fixed conditions so that every car is measured the same way. That is the whole point of it.

The lab conditions behind the number

To understand why your real range is different, it helps to picture how the test is run.

• It is carried out at a comfortable temperature of around 23°C, not on a frosty January morning.
• Energy-hungry extras like the heater and air conditioning are switched off.
• The car is run through a set drive cycle on a rolling rig, not out on a motorway.
• The average speed across the whole cycle is only about 46.5 km/h, which is under 30 mph.

Read that last point again, because it is the one that catches people out. The WLTP cycle spends a lot of its time at low, gentle, town-style speeds. EVs are at their most efficient in exactly those conditions. So the test naturally flatters the range compared with how most of us actually drive.

Why WLTP exists at all

If the number is not the real-world number, why bother with it? Because it does one job very well: fair comparison.

Every EV sold new is put through the identical procedure, in the same conditions, measured the same way. That means when one car quotes 280 miles and another quotes 320, you can trust that the second genuinely goes further under the same test. WLTP is a level playing field. It is a like-for-like yardstick between models, not a promise of what you will get on your commute.

Think of it the way you think of the official fuel economy figures on a petrol car. Nobody ever quite matched them either, but they let you compare one car against another.

Why your real range is lower

So how far below WLTP does real life land? The honest answer is that it varies with the car, the weather, the roads and the driver. But the research gives a reliable ballpark.

Motability's analysis of claimed versus real-world range found that UK driving typically delivers somewhere around 78% to 85% of the WLTP figure, with real-world range often 10 to 30% lower once you factor in motorways, winter and running the heater. Independent fleet testing reported by Fleet News found EVs falling short of WLTP by roughly 15% on average.

So as a rough rule of thumb, knocking somewhere between 15% and 25% off the advertised WLTP figure gets you close to a realistic everyday number for a UK car. A 300-mile WLTP EV is, in practice, more like a 225 to 255 mile car in mixed use, and less again on a cold motorway run. We go into the reasons in more detail in Why Does My EV Have Less Range Than Advertised?.

None of this means the figure is dishonest. It means the figure is a lab result, and your driveway is not a lab.

The thing WLTP does not tell you

Here is the part that matters most if you are buying used, and it is easy to miss.

WLTP measures the car when it is brand new. It says nothing whatsoever about the current condition of a used car's battery. A three-year-old EV still carries the same WLTP figure on paper that it had on day one, even though its battery has aged since then.

Every EV battery slowly loses a little capacity over time, which is why a used car's real range is shaped by two separate things: how far below WLTP real-world driving pulls it, and how much the battery itself has degraded. The advert only ever speaks to the first car, in ideal conditions, when new. It is blind to the second question entirely.

That second question, the actual health of this specific battery, is the one that decides what you are really buying. It is measured not by WLTP but by State of Health, and it is fast becoming the number that matters most on a used EV. We explain why in State of Health Is the New Mileage for Used EVs.

How to know the number that actually matters

WLTP is a fine starting point for comparing models. It is a poor guide to the used car in front of you, because it describes that car as it left the factory, not as it stands today.

The only way to know the true condition of a specific used EV's battery is an independent, cell-level test, not a figure copied from a brochure or a percentage the dashboard chooses to show. That is exactly why an independent battery check is worth having before you buy: it measures this car, now, rather than an average of every car of its type when new.

The AVILOO FLASH test does precisely that. It reads the battery through the car's OBD port in about three minutes and produces a TÜV Certified certificate of the real State of Health. WLTP tells you what the model could do when new. The certificate tells you what this battery can do today.

Comparing used EVs and want to know the real condition behind the advert? Book a £100 certified battery test and buy on facts, not on a lab figure.