Mautofied Community

Why do bigger tires make my car rev faster but the diameters is the same as old ones?

Need more information to answer that. What kind of car? Engine? Transmission? Factory wheels specifications? What are the specifications of the new wheels/tires? What do you mean "rev faster"?

I guess you mean "wider" and not bigger considering you said they are the same diameter. Wider will not make it rev faster or enhance engine performance whatsoever. The only advantage to wider tires is lateral corner and acceleration traction.
The "rev faster" is all in your head.
The only thing that will make your engine rev faster would be a lighter flywheel (manual trans). Anytime you can lose centrifigal weight from the rotating assembly, it will allow the engine to reach higher RPM's faster.