A new test from German Aviloo shows a difference in range. Roof load increases air resistance more than trailer load on the highway.
A new test of a Volkswagen ID.4, conducted by the German company Aviloo, reveals that it is often the drivers' own fault that their cars have poor range.
Electric cars are sensitive to increased air resistance. This affects the range more than for cars with combustion engines. Therefore, the placement of luggage is important.
Air resistance increases with the square of the speed, so the effect is most noticeable at higher speeds.
Aviloo used a Volkswagen ID.4 for the test. They covered a fixed route over a distance of 120 kilometers.
The route was on a motorway. Motorway traffic is relevant, as this is often where the range is worst in electric cars.
The test was carried out in three stages. First, the car was driven without any additional load. This gave a base consumption for the specific distance.
The car was then tested with three bicycles mounted on the roof. Roof racks and bicycles increase the frontal area of the car. This increases wind resistance significantly compared to an unladen car.
VW ID.4 Range Test: Roof Load vs. Towbar
Finally, the same three bikes were placed in the back of the car. The bikes were on a rack mounted on the towbar. This is an alternative method of transporting bikes.
Positioning behind the car typically provides less air resistance. The bicycles are partially sheltered behind the car itself. This affects consumption less. The airflow around the car is less disturbed.
The range with a roof box or bicycles has been much discussed. Many electric car owners are unsure about the effect. The new test sheds light on the issue.
Knowing about range loss is useful for electric car owners. This is especially true when planning longer trips. Vacations with packed luggage require attention to consumption.
The Volkswagen ID.4 is a popular electric car in many countries. The results from the test may therefore be relevant to many. However, other electric cars will experience similar effects. The ID.4 is a mid-size SUV, where aerodynamics already play a role.
How to optimize your electric car's range
The test indicates that a load on the towbar is best. This is true if you want to minimize the loss of range. The increased air resistance from a roof load appears to be significant.
Understanding aerodynamics becomes more important with electric cars. Even small changes in the shape of the car can affect fuel consumption. This is especially true when driving on the highway at constant high speeds.
– We would like to create clarity with our study. There are many half-truths about extra consumption due to reading.
– Our measurements clearly show that a trailer has minimal influence on range and driving behavior. Roof loads, on the other hand, result in noticeable losses.
– The most important physical reason for the clear differences is air resistance – it does not increase linearly, but quadratically.
"At double speed, air resistance quadruples energy consumption," says Aviloo's technical director Nikolaus Mayerhofer.
Aviloo specializes in battery testing for electric vehicles. Their testing methods provide insight into the performance of electric vehicles. This applies under different conditions and usage patterns.
The test focused on highway driving at a given speed. Speed also has a major impact on range. Higher speed increases air resistance exponentially. Therefore, range drops faster at 130 km/h than at 110 km/h.
The test specifically compared roof load with rear load. It provides an insight into the role of aerodynamics on range. The choice of loading method has a clear impact on an electric car like the VW ID.4.
Are you interested in electric cars? Here at Boosted you can always read the latest news about electric cars. Even when things go wrong.
For example, Audi must now recall 6,000 Danish electric cars with a dangerous defect. Read more about it here .
