What's wrong with the fuel now. I daily drive a carb with today's fuel and never have a problem. It's called tuning. If anything this new fuel never gums up and will completely evaporate before it will ever clog anything up.
The only way today's fuel is inferior is that it's diluted with anhydrous ethanol, most often 10%. At the 10% blend rate, the resultant fuel contains between two and three percent less energy per volume unit than straight gasoline—which means if you get 15 mpg on straight gasoline, you'll get 14.6 to 14.7 on the E10 gasohol, with all other factors equal. The bigger problem with anhydrous ethanol in gasoline is corrosion of fuel system metals. There's a weird, cheap, very effective, win-win-win solution to this problem that also negates the 2 to 3 percent energy deficit, but for some strange reason it's not being used.
Other than the alcohol issue, today's gasoline is a vastly superior product to the dirty gunk of the past.
