What type of oil are you using? Conventional or Synthetic? The reason I ask is conventional oil has an inherent characteristic of being volatile. Meaning at normal operating temperatures, some components of the oil burn off or evaporate. Synthetic oil is resistant to this type of evaporation loss. Although, one quart of oil in 750 miles seems a bit excessive for evaporative loss. Regardless, it could be plying a roll in your oil loss issue. What does the oil look like? Such evaporative loss also increase the oils viscosity. What is the engines operating temperature? Is it higher than normal? Does the engine ever overheat?

Just a couple other possibilities to consider.