You can substitute 195/55-16 or 175/65-15 but your speedometer will be off with either size. My advice is to stick with the OEM size which was computer designed for your car to give the best mileage, handling, traction, and ride.
no
Yes, they can
Yes, you can
Yes, they can
Yes, you can
Normally. yes.
Yes, you can.
Yes, that is a reasonable substitution.
Yes, this is an excellent substitute.
Yes, that is a pretty good substitute.
no there is too much height difference
Yes, if you mount as a pair. Both tires on axle must be the same