What is the difference between the Audi A5 40 TFSI and 45 TFSI engines?

I'm looking at purchasing an Audi A5 but I'm not sure which engine to go for. Can someone explain the differences between the 40 TFSI and 45 TFSI options?

The main difference between the 40 TFSI and 45 TFSI engines is the power output. The 40 TFSI has a 2.0-liter 4-cylinder engine that produces 188 horsepower and 236 lb-ft of torque, while the 45 TFSI has a slightly larger 2.0-liter 4-cylinder engine that produces 248 horsepower and 258 lb-ft of torque.