The units have a maximum speed of and up to four sets can be worked in multiple to form a 12-car set, although platforms are only capable of handling 8-car trains. The 318 can also operate in multiple with the slightly newer Class 320 in a six car formation, which is regularly used on the North Clyde and Argyle Lines. Upon the introduction of the Class 334s onto Ayrshire/Inverclyde routes in 2001, both the 334 and 318 were found operating these lines together.