My car goes into the 400s. My wife's car has one of the newer 360L tuners with many more channels, a significant number of which are delivered via a cellular radio rather than by satellite. It's pretty neat.The radio in my 2018 VW has no problem tuning in the highest SiriusXM channel numbers, but the car's gauge cluster display must use an 8-bit value to store the channel number, because it maxes out at 255.