Toyota will adopt Tesla-style cast bodies that might be impossible to fix

Toyota has reportedly demonstrated a prototype production line for a cast car chassis, made by a process sometimes referred to as “gigacasting.” The new manufacturing technique may offer significant production advantages, but could hand consumers the short end of the stick when it comes to the castings’ repairability.

The casting process was demonstrated at Toyota’s Myochi plant in Japan, where it fabricated the rear third of a unibody at an event attended by Nikkei Asia. Cast unibodies are proposed as a potential replacement for conventionally assembled unibodies, which combine shaped metal pieces via welding, industrial adhesives, and more to form a car’s frame. In an example given by Toyota, a unibody built with traditional methods required 86 parts, 33 steps, and hours on an assembly line. But in its demo, the company reportedly produced a cast equivalent in a mere three minutes.

Toyota reportedly expects cast bodies to reduce production complexity, costs, and preparation time, not to mention make more efficient use of factory floor space. Fully optimised, Toyota anticipates it’ll generate 20 per cent higher productivity than its competitors, and could halve body assembly time from 10 hours.

The technology will reportedly first be used for a mass-produced electric vehicle that will arrive in 2026 with cast front and rear body structures. Toyota reportedly plans to make cast bodies integral to its EV strategy, though 40 per cent of its EVs in 2026 will still use variations of the existing TNGA architecture.

Cars with cast unibody components are already sold by Tesla, which nicknamed the technique gigacasting. However, Tesla’s pattern of poor quality control emerged here too, with one driver of a Model Y made in Austin, Texas finding frame fissures they could shine a light through. This doesn’t mean casting is unsuitable for unibodies, as Toyota, whose identity and image are rooted in quality and reliability, likely would not ship a car with such a worrying flaw.