Why does Audi R8 have a V10 engine?

I've noticed that Audi R8 uses a V10 engine, while most modern sports cars use smaller engines. What is the reason behind Audi's decision?

The V10 engine offers a more balanced power distribution and smoother power delivery, resulting in better handling and acceleration.

Audi's V10 engine is based on their successful Le Mans racing car engine, giving it a powerful and proven pedigree.

Smaller engines may be more efficient, but the V10 gives the R8 its unique and iconic engine sound that adds to the overall driving experience.