Suzuki Vitara JLX I want to reduce the tires to reduce fuel consumption. What size should I buy? What are your recommendations?

Good day guys.
I have a 2001 Vitara JLX
The vehicle has an upgrade kit.
Tires on the vehicle 235/75/15
To reduce fuel consumption
I want to shrink tires
To what extent should I take it? What are your recommendations?
( vehicle original tire size: 195/80/ 15
Does it look bad aesthetically?