When using 'var' affects performance?

When using 'var' affects performance?

If a method returns an interface, it is possible that using 'var' would affect performance.

Effective C# - 50 Specific Ways to Improve Your C#

Effective C# - 50 Specific Ways to Improve Your C#

Effective C#: 50 Specific Ways to Improve Your C#, Third Edition

• By: Bill Wagner
• Publisher: Addison-Wesley Professional
• Pub. Date: December 12, 2016
• Web ISBN-13: 978-0-13-457929-0
• Web ISBN-10: 0-13-457929-1
• Print ISBN-13: 978-0-672-33787-1
• Print ISBN-10: 0-672-33787-8
• Pages in Print Edition: 288