I plan to replace the front brake discs on my 2023 Skoda Octavia MK4 due to vibrations in the cabin during sudden braking (hard braking at high speeds, under 140 km/h). I would like to know the diameter of the discs because I found two options: 312mm and 288mm.
Which diameter and brand would you recommend?
Thank you in advance.

Use the size of front brake discs that the car left the factory with, unless you want to modify the car.

If the Octavia MK4 has front wheel drive and not more than 110kW/150PS, it probaby has the 288x25mm front brake discs. However, it's always best to check the car's build codes to be sure. The Skoda parts catalogue lists 288x25mm, 306x26mm, 312x25mm, and 340x30mm front brakes discs for the Octavia MK4.

In a 2021 ADAC brake test, the Brembos had by far the worst wear out of the six brands that were tested. The other brands were ATE, VW, Bosch, Zimmermann, Ridex. ATE won the test.

ATE brakes

https://www.ate-brakes.com/products/disc-brakes/ate-ceramic-brake-pads/#:~:text=ATE%20Ceramic%20%E2%80%93%20winner%20of%20the%20ADAC%20test&text=Ten%20years%20have%20passed%2C%20but,brands%2C%20including%20one%20OE%20product.

Edited 28 March, 20251 yr by Carlston

Thank you very much for the detailed response. I will eliminate BREMBO and consider another brand (ATE or TRW) 288mm diameter