Hi, I have a Z140bh. I know the max SD size is a 16gb card. Does anyone know what the size limitation is on a USB flash drive? I have a 64gb flash drive that has around 59gb of music on it. When I put it in the AVIC I am only seeing a small portion of my music folders. Is this because of a size limitation?

Thanks,

Steve

You can definitely put a larger card than 16GB.  Just make sure it's formatted to FAT32.  I currently have a 32GB one that I use to put music videos. 
You may have too many songs, I think the max is around 2,000, which is why you can't see them all.

I'm thinking of getting one of those Toshiba FlashAir SD card that have a built in WIFI.

Here's the issue you're going to face with a large USB or SD drive.

The Pioneer head unit must index the music folders each time on start up. The larger the files, the longer it will take. I had a 64 G drive that took nearly two minutes before it was ready to play, and it won't index while you're using another audio source.

As previously noted, either the SD or USB drives must be formatted in FAT32, exFat will not work. Windows won't natively format a drive larger than I believe 32 G as anything but exFAT. You'll have to get a third party program to do it.

One other point. I've heard of sort issues with USB and SD drives. It's kinda hard to find a song or album if you've gotta go through each file to find it.

I finally stepped to the plate and got an iPod Classic 160 G which solved my problem.

Yeah I've been using a dedicated iPod Classic for years for the simplicity.  The only content I put on the SD card are music videos ripped from youtube.

I have a 128gb usb flash thumb drive that works just fine with my z140bh. It's formatted as FAT32 and it came that way when I bought it.

The HU will not read more than 2,500 files or 300 directories on the drive though.. that is a limitation of the head unit.

startup time is fairly quick.. less than 60 seconds.