yes and no....they must always be the same diameter and width on the same axle. 4 wheel or all wheel drive vehicals all tires must be the same. It is common on rear wheel drive sport cars to run much larger and wider tires on the rear.
For SAFETY and HANDLEING YES.
Yes, just be sure all the tires are the same size and put winter tire on drive axils, never use different size tires on a 4x4 all four must be the same size, or you will damage transmission.Answeryes
yes
NO. As long as they all are the same size.
By ratio if you mean size, the answer is no unless the car comes from the factory with a different size rear tires than front tires like some sports cars. In that case you would have 2 tires the same size on the front and 2 tires another size on the rear. You should never ever run 2 different size tires on the same axle. Therefore you would never have a situation where you would have 3 tires one size and then 1 tire another size.
No, they can't fit on the same car.
If they are of the same size and load capacity, yes.
Yes, if you install the correct tires and use 16" rims/wheels as well. Install tires that end up giving you the same overall diameter as the OEM 15" tires. You can use a tire size calculator to determine the size tires you need.
No, not less one of the tires is out of balance. But it is never, ever, a good idea to have two different size tires on the same axle. This is a big no-no.
They can but changing tire size will change speedometer readings and the way your car handles. You also must have all four the same size. There is a link to a tire size calculator in related links.
The size of the rim is not what changes the ride. IT is the amount of tire between the rim and the road.
yes problems happen all the time with tires no the right size go find what to right size is in manual or shop and get the right size tires