You've been lucky. I don't know that you would see many problems with a daily driven card, its more to do with what the ethanol does if it is left to sit around for a long period of time (say a few months). If you are burning it, not an issue, but if not, it sort of separates itself from the gasoline, and then starts doing its evil thing. It doesn't matter in more modern cars, as their fuel system is designed to stand up to ethanol; it is with older cars not designed to be ethanol compatible (because ethanol wasn't being used in fuel when those cars were designed/manufactured). Things like fuel lines deteriorating, carb floats (assuming they were not brass) no longer floating, intake and carb base gaskets leaking, carb passages getting clogged up, etc.
Also, you probably didn't save as much as you think you did. This is because your mileage (mpg or Km/100 L (due to the lower energy content of ethanol than the gasoline it displaced)) went down, and further dropped when you slowed down your advance curve, which can also drop gas mileage. Maybe you only lost 1 mpg, but over 17 years, it adds up. While you still might be ahead, it isn't a straightforward savings; you would have to do a lot of calculations. Also, in Calgary, there is no price difference between regular gas with or without ethanol. So no cost savings compared to ethanol free regular gas. There is a savings vs. premium ethanol free, but that cost savings is an apples to oranges comparison (regular, with or without ethanol is always cheaper than premium, so ethanol has not cost advantage vs. ethanol free regular); you probably would have had better savings with regular ethanol free vs. ethanol regular, as you would have had better gas mileage with the regular ethanol free than you did with the ethanol regular.
