The U.S. Supreme Court has been slow to rule on many of the biggest cases on this year's docket. Maybe that's because some of the justices are prone to procrastination, or maybe, like seasoned TV scriptwriters, they're just playing America like a violin, getting us all worked up for a rousing finale.

This week, however, we've entered the homestretch, and key decisions are finally beginning to roll out. One of those arrived yesterday, when the Supreme Court announced that it would not hear appeals from trade groups opposed to E15 gasoline. That was a disappointment to many automakers, fuel companies, and car fans. 

HOW WE GOT HERE

As we've discussed before, ethanol standards got a shot in the arm back in 2007, when then-President George W. Bush signed the Energy Independence and Security Act into law. (Insomniacs can pore over a PDF of that document here.) Part of the Act stipulated that refineries had to use increasingly greater quantities of biofuels like ethanol in the production of gasoline.

Although that might sound awesome to green car fans, there are some downsides. For starters, E15 -- which uses 15% ethanol -- isn't as potent a brew as the current E10 blend, much less pure gasoline. As a result, it'll likely put a dent in our fuel economy.

Also, E15 may cause corrosion and other damage to engines and fuel systems. That's why many automakers hate it

The Environmental Protection Agency has vouched for E15, insisting that it's safe for cars from model-years 2001 and later. However, Chrysler hasn't even approved E15 on current vehicles, and many automakers say that using E15 will void the warranty on your car. 

And that's why trade groups representing refineries, car companies, and other businesses filed a lawsuit, asking federal judges to overturn the EPA's approval of E15. Back in August, a Circuit Court of Appeals in the District of Columbia ruled that those groups lacked standing to sue, and yesterday, the Supreme Court declined to hear the plaintiff's appeal. Translation: case closed.

There's a possibility that the trade groups could lobby Congress to pass a bill outlawing E15, but they'd need to negotiate two very divided houses and overcome powerful agendas put forward by the Administration and states in the U.S. corn belt.

OUR TAKE

Given the Supreme Court's decision to let the appellate court ruling stand, the arrival of E15 is pretty much a done deal. There are at least two ways to look at that.

If you're thrilled by the thought of an 85/15 blend, congratulations. Life's pretty good. Perhaps you should go buy a lottery ticket.

If, on the other hand, you're bummed at the idea of putting more corn in your gas hole, here are some suggestions for solace:

1. E15 won't become ubiquitous overnight. As Detroit News notes, out of America's 180,000 gas stations, E15 can currently be found at around 24. And since the remaining 179,976 will need to install new blender pumps to sell the stuff, it'll take a while for E15 to appear.

2. No station is required to carry E15, so the adoption rate could be slow. (Though E15 will likely be slightly cheaper than E10, which could hasten the transition.)

3. E10 and lighter blends will remain on tap for the forseeable future. That's because E15 hasn't been approved for motorcycles, heavy-duty engines, off-road vehicles like boats and snowmobiles, or any vehicle from before the 2001 model year. 

4. Going forward, automakers are likely to tweak their vehicles to accommodate E15. So, the car you drive today may not handle it very well, but your next one probably will.

5. As hybrid and electric vehicles slowly gain market share, the ethanol content in our gasoline may become a moot concern. After all, if our future cars use less gas -- or no gas at all -- who cares what's in the pumps?

6. If all else fails, close your eyes and think of England, where E10 is still a big deal.

[h/t John Voelcker]

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