Are expenses lower for multifamily or single family rentals?

[Tonga Nfor]

I have mostly invested in small multifamily residential buildings 5-20 units. Typically used 45-55% of rental income as expenses (mortgage) when doing my quick & dirty math.

I’m now considering single family & duplexes. Are expenses typically lower than multifamily? What is typical expense/income ratio for single family/duplex rentals?

Thank you