Page 1-3 in this document https://www.fleet.ford.com/cmslibs/content/dam/aem_fleet/en_us/fleet/showroom/resources/2017-C-Max-Modifiers-Guide.pdf
contains the following:
WARNING: Only use replacement tires and wheels that are the same size and type (such as P-metric versus LT-metric or all-season versus allterrain) as those originally provided by Ford. Use of any tire or wheel not recommended by Ford can affect the safety and performance of your vehicle, which could result in an increased risk of the loss of vehicle control, vehicle rollover, personal injury or death. Additionally, the use of non-recommended tires and wheels could cause steering or suspension failure. If you have questions regarding tire replacement, see an authorized Ford or Lincoln dealer.
NOTICE: Do not install an off road, aggressive tread or incorrectly sized tire. Any of these may cause elevated stress to the steering system. This can cause the power steering system to overheat and shut off the power assist, which can affect the safety and performance of your vehicle.
Hope this helps.