Asger Risom
For all the advanced technology and screens packed into modern vehicles, automakers are systematically ditching spare tires to cut weight and free up battery space, replacing them with chemical sealant kits that leave drivers stranded when facing major sidewall damage.
For decades, dealing with a flat tire was a miserable but predictable ritual: pull off to the shoulder, dig the rubber donut and scissor jack out from under the trunk floor, and spend 20 minutes getting grease on your hands. Today, if you open the cargo floor on a new vehicle packed with massive touchscreens and radar sensors, there is a good chance you will find nothing more than a bottle of goo, a 12-volt air compressor, or a big empty plastic tray.
According to an analysis by Motor1, the traditional spare tire is rapidly vanishing across the industry, with up to a third of new vehicles now shipping without one. Far from being a random oversight, the removal of the emergency wheel is the result of a ruthless engineering war over vehicle weight, fuel efficiency, and battery packaging.
Shaving pounds to chase fuel efficiency
The primary driver behind the missing spare comes down to basic physics: mass kills efficiency. A full-size wheel or even a steel space-saver donut, combined with a heavy jack and lug wrench, adds significant weight to a vehicle’s curb weight.
With governments imposing increasingly strict fuel economy and emissions targets, automakers are hunting down every single unnecessary pound. Ripping out 30 to 50 pounds of emergency hardware that might spend its entire life unused gives engineers an easy, low-cost win on the spec sheet.
Physical space is just as precious. As automakers electrify their fleets, the cavernous tub that once housed a spare tire has become prime real estate. Designers now use that underfloor volume to tuck away hybrid battery packs, rear electric motors, or complex exhaust systems without sacrificing cabin legroom or cargo space. Ditching the hardware also saves manufacturers money on assembly lines—a cost reduction that rarely reflects on the window sticker.
Sealant kits and the sidewall reality check
To fill the gap, manufacturers generally rely on run-flat tires, built-in roadside assistance, or a repair kit containing a compressor and liquid sealant. But as drivers frequently discover the hard way, these modern workarounds have glaring limitations.
Run-flat tires feature reinforced sidewalls that let you limp to a shop at low speeds after losing air, but they ride harsher and cannot survive major structural damage. Sealant kits are even more conditional: while a shot of chemical goo can plug a simple nail hole in the center of the tread, it is completely useless against a torn sidewall, a shredded tire, or a bent rim. To make matters worse, sealant has a shelf life. An emergency bottle left baking in a trunk for five years can separate into useless sludge long before you ever get a puncture.
Tire-pressure monitoring systems (TPMS) now alert drivers to slow leaks before a tire goes completely flat, giving you time to reach a service station. But for anyone traveling through rural areas or off the grid, relying on a tow truck instead of a 15-minute tire change remains a frustrating trade-off for a fraction of a mile per gallon.
