The owner's manual for the CX-5 says to prevent electrical failure, do not to use USB devices that require more than 10.5 W (DC 5 V, 2.1 A) in the USB outlet. The cables for iPhone are rated 12 W, DC 5V / 2.4 A. I'm sorry if this is a stupid question, but is it safe to use any iPhone cable in my car?

 

Sure as long as USB device not require more than 10.5 W DC 5 V, 2.1 A