Keep your fridge at 7°C and your freezer at -18°C. Every degree lower increases energy consumption by about 6%. Also, ensure there is enough space behind the unit for air to circulate.
The cost here isn't just the motor, but the energy required to heat the water to high temperatures. Simple Strategies to Lower Your Costs Keep your fridge at 7°C and your freezer at -18°C
Modern detergents work great at lower temperatures. Dropping your wash cycle from 60°C to 30°C or 40°C can cut the energy used per load by half. Keep your fridge at 7°C and your freezer at -18°C