What is the best automatic transmission for high horsepower?

For high-horsepower models, 8-speed automatic transmissions (such as the GAZOO Racing direct-drive 8AT equipped in the Toyota GR Yaris) currently offer the best overall performance. When paired with the 300-horsepower 1.6T engine, it enables a 0-100 km/h sprint in just 5.2 seconds, while its dedicated cooling system ensures stability. For applications requiring higher load capacity, 6AT transmissions (like those in the Toyota HiAce SLWB) can be matched with the 174-horsepower 2.8T diesel engine, delivering both durability and smooth operation. Mazda's Skyactiv-Drive 6AT showcases exceptional synchronization between naturally aspirated engines and transmissions, though it prioritizes linear power delivery over peak performance. In summary, the 8AT's closer gear ratios, rapid shift programming, and thermal management advantages make it ideal for maximizing the potential of high-horsepower vehicles.