This post was contributed by Sebastian Blanco, editor in chief of AutoblogGreen. Jim Motavalli is on a month-long assignment.

The EPA is trying to get more ethanol into your car.

The latest step in the under-the-radar process was announced Friday, when the agency said that E15 — a blend of 15 percent ethanol and 85 percent gasoline — is safe for all cars on the road that were made in 2001 or later. Until this announcement, the EPA had only approved E15 for model year 2007 and newer vehicles, so it's a pretty big deal. 

There are many reasons for the new announcement, but one big one is a push from the ethanol industry, which has been worrying about something called the "blend wall" for years. Currently, most gas sold in the U.S. has at least some corn-based ethanol in it, but not more than 10 percent. Ethanol producers say they can make more ethanol than what is needed for that 10 percent, and that's what's called the blend wall. By approving E15, the EPA pushes the wall higher and makes corn states happy.

Not everyone is so pleased. Environmentalists, for example, have legitimate concerns about the negative effect of corn-based ethanol, like how much petroleum is used to grow the corn and if the land could be used to grow other things, like food.

Automakers, too, have serious concerns. They worry that the new E15 fuel could damage vehicles, and that they're going to have to deal with angry customers who complain that their car needs to be covered by a warranty that didn't take E15 into account.

This is why the EPA wants to make sure that people will know what they're putting into the tank. In October, the EPA proposed a bright orange warning label that would go on every pump that dispenses E15. The ethanol industry didn't like that warning, and came back and proposed a milder warning label, a baby blue square that's completely inoffensive. No decision has been made on what sticker you might see, in part because legal challenges are holding up E15 from reaching the pump just yet.

What does it mean for you? Right now, very little. But, if you do see E15 at the pump some day — and it will be labeled — you need to know when your car was made. If your vehicle was made in 2007 or later, there is little reason to worry. If you drive a flexfuel vehicle, then your engine can burn any ethanol/gas blend up to E85, so E15 is no problem. If you don't fit into one of these categories, then you will likely be fine with E15 (the EPA says so, anyway), but you might want to stick to "normal" gas if you're unsure.

Jim Motavalli ( @jmotavalli ) writes about cars, technology and the environmental world to anyone curious enough to ask.