If engine size is 115.6 cu in, would it be a 2.5i or a 3.0i?

116.5 cu in is neither a 2.5 or 3.0. It's a 1.9L. 1 liter is roughly 61 cu inches.

The difference is the the size of the engine. 2.5i is 2.5 liters, 3.0i is 3 liters. The 3.0i will have more power but will get worse fuel economy. The 2.5i will have less power but better fuel economy. I know that a 3 liter engine is about 181 cu. inches. 2.5i is about 150 cu. inches. I don't know what 115.6 cu inches is.

engine displacement, horsepower, torque, suspension