Why don't BMW new energy vehicles use run-flat tires?
2 Answers
Run-flat tires are much heavier than regular tires, adding dozens of kilograms across four tires. Electric vehicles generally don't come with spare tires, partly due to geometric matching issues but also for weight reduction. Here's relevant information: 1. Function of run-flat tires: Run-flat tires primarily rely on thickened rubber sidewalls that can support the vehicle's weight even when the tire loses pressure. If the BMW 5 Series new energy model had run-flat tires, even a blowout wouldn't cause severe tire deformation that would significantly affect its driving. 2. Vehicle stability control: This is a braking system that prevents skidding under emergency driving conditions. If the BMW 5 Series new energy model is equipped with a vehicle stability control system, it can maintain optimal stability in various situations and help preserve dynamic balance.
I've always been very interested in this issue, especially after driving several electric vehicles. BMW's new energy models like the i-series don't use run-flat tires mainly due to weight concerns. New energy vehicles already have heavy batteries, and run-flat tires add even more weight, increasing the overall burden and affecting both range and acceleration performance. Additionally, new energy vehicle designs emphasize efficiency and energy savings, and run-flat tires have higher rolling resistance, which can reduce battery efficiency and shorten driving distance. BMW likely opted for conventional tires to optimize overall efficiency. I've also noticed that run-flat tires offer poorer comfort and generate more noise, which can disrupt the driving experience in electric vehicles that emphasize quietness. As an owner, if you encounter a flat tire, the i3 usually comes equipped with a tire repair kit or roadside assistance service, ensuring safety isn't compromised—a topic frequently discussed in community forums and quite practical.
