Note that if you live in California, what you can buy depends on where you live and what time of year it is. As you walk down the aisle in the grocery or drug store, pay attention to what blue jug of cheap fluid says on the label. If it says "Protects to 32 degrees", it's basically just blue water with a VERY SMALL amount of alcohol in it, and it means you live in a "non-mountainous" area and/or it's "summer", both as defined by state law. If you see on the label "Protects to 22 degrees (or some lower number)", then it's blue water with a bit more alcohol in it and you must either live in a "mountainous" area or it's "winter".
The reason for this are the state laws on VOC (Volatile Organic Compound) emissions. And don't think this applies only to grocery store products, all resellers and distributors have to abide by these laws as well. Personally, in the past I've made it a point to stock up on the "good stuff" whenever I see it on the shelves because much of the year in the LA area you can't get anything but the blue water.