Electric vehicle (EV) drivers are facing a new kind of challenge as record-breaking heatwaves sweep across Europe. In a recent test conducted by the UK-based publication What Car?, three of the latest EV models were driven through the scorching roads of Andalusia, Spain, to see how high temperatures would affect their battery range. The results were eye-opening, especially for Tesla owners.
The test took place on September 14, 2025, and included the Citroen e-C3 Max, Kia EV3 Long Range GT-Line S, and Tesla Model 3 Long Range RWD. The route spanned from Seville to Cordoba and Montoro, before heading south to the coastal region of Aguadulce. The ambient temperature peaked at a sweltering 111°F (44°C), pushing these vehicles far outside their comfort zones. All three cars were driven at highway speeds, a scenario that already challenges electric efficiency, even before factoring in the intense heat.
According to What Car?, the Citroen e-C3 Max, equipped with a 44-kilowatt-hour battery and an official WLTP range of 199 miles (320 km), managed only 142 miles before needing to recharge. This represents a 29% shortfall from its advertised range, with an efficiency of just 2.7 miles per kilowatt-hour. The Kia EV3, with its larger 81.4 kWh battery and a claimed range of 362 miles (582 km), achieved 246 miles—32% less than promised, and an efficiency of 2.9 miles/kWh.
But the biggest surprise came from the Tesla Model 3 Long Range. Despite its advanced liquid thermal management system and a robust 80 kWh battery rated for 436 miles (702 km) on paper, the Tesla could only cover a theoretical maximum of 244 miles in the extreme heat. This amounts to a staggering 44% reduction from its official range, even though it posted the best efficiency of the group at 3 miles/kWh. As What Car? noted, "The Tesla Model 3 Long Range could only cover a maximum of 244 miles in the stifling heat. This is 44 per cent down on its 436-mile official range."
Will Nightingale, reviews editor at What Car?, put the findings into perspective: "Our extreme temperature test shows that range and efficiency plummet in very hot conditions. The three EVs fell an average of 35 per cent short of their official figures, which is worse than the result we achieved in our most recent winter range test and more than double the discrepancy seen in the 2024 What Car? summer range test."
To better understand just how dramatic this drop is, it helps to look at previous results. Last summer, What Car? tested 12 popular EVs in the UK, where temperatures ranged from 17 to 23 degrees Celsius (63 to 73°F). There, the average range shortfall was just 14%. The latest test in Spain, however, saw an average drop of 35%—a clear sign that extreme heat can be just as punishing for EVs as the cold snaps that have long been known to sap battery life.
Why is this happening? Lithium-ion batteries, the heart of modern EVs, are happiest in a narrow temperature band—usually between 68°F and 77°F (20°C and 25°C). Stray too far from this comfort zone, and performance suffers. In cold weather, batteries must expend energy to heat themselves and the car’s cabin, which drains power. In excessive heat, the challenge flips: batteries work overtime to keep themselves cool, while drivers often crank up the air conditioning to stay comfortable, further draining the battery.
Interestingly, while the Citroen e-C3 Max struggled with both range and charging speed—taking 74 minutes to charge from 3% to 80% due to a less advanced thermal management system and a slower charger—the Tesla and Kia models fared better on the charging front. The Tesla Model 3 charged from 9% to 80% in 32 minutes, just five minutes longer than its official 27-minute claim. The Kia EV3 managed a similar feat, charging from 10% to 80% in 31 minutes, just three minutes off its stated time. This suggests that, at least for now, fast charging in extreme heat is less of a concern than range loss, provided the car’s cooling systems are up to the task.
One unique factor affecting the Tesla’s result was its full-length glass roof. According to Motor1, the journalists conducting the test noted that the Tesla’s glass roof—even with a cover—required them to run the air conditioning at a higher setting than in the other two cars. This extra cooling demand had a disproportionate impact on the Tesla’s final range, highlighting how design choices can interact with environmental factors in unexpected ways.
As Europe and other parts of the world experience more frequent and intense heatwaves—temperatures in the south of England have already surpassed 40°C (104°F) this year—these findings are increasingly relevant for current and prospective EV owners. As Will Nightingale observed, "While extreme heat is still (thankfully) quite rare in the UK, the planet is undoubtedly heating up. We’ve already seen temperatures of more than 40 degrees C in the south of England and multiple heatwaves have swept the country this summer."
The hope, of course, is that EV technology will continue to evolve. Nightingale expressed optimism: "So, hopefully, as technology advances, EVs will become better at coping with extreme temperatures." Battery chemistries, thermal management systems, and even car designs may all need to adapt as climate patterns shift and drivers demand more reliable performance year-round.
For now, though, the lesson is clear: if you’re planning a long summer road trip in your electric car, be prepared for your actual range to fall well short of what’s advertised—sometimes by nearly half. Keep an eye on your battery, plan charging stops carefully, and remember that a little shade (and perhaps a less panoramic roof) can go a long way in helping you reach your destination.
This test from What Car? underscores the importance of real-world trials in helping consumers make informed decisions. As the world heats up and electric vehicles become the norm rather than the exception, understanding how these cars perform outside laboratory conditions will be essential for both manufacturers and drivers alike.
