Gentle acceleration and looking ahead help reduce unnecessary speed changes. Leave enough space to slow smoothly rather than rushing toward traffic and braking hard. On open roads, use a steady, legal speed; higher speeds generally require more energy to overcome air resistance. Cruise control may help on suitable flat roads, but remain attentive and avoid using it where conditions change quickly.
Remove heavy items you do not need and take off unused external racks when it is safe and practical, since extra weight and drag can increase energy use. Keep tires at the pressure recommended by the vehicle maker and address dragging brakes or a wheel alignment concern through a professional. Use the correct engine oil and follow the service schedule in the manual.
Short trips can use more fuel per mile because the engine may not reach its efficient operating temperature. Combine errands when convenient, but do not drive when tired or make a longer trip solely to chase a small saving. Track your consumption over several fill-ups to spot a meaningful change. A sudden drop in efficiency can have many causes and may deserve a mechanical check.