It's unfortunate that the previous owner used that oil. I don't have the owner's manual for your car but I'll bet it doesn't recommend 10W-30.
A person can argue that using a good brand of petroleum based oil changed frequently is more than adequate. I agree. However, I personally avoid the lighter weight oils and using a synthetic allows me to use a 15W-50 oil in temps where a lighter weight petro based oil would be needed.
My suggestion is to use a good name brand petroleum based 10W-40.