Hyundai is potentially set to unveil a 34 mpg combined Blue version of its Elantra with a start/stop system.

Hyundai could be planning to resuscitate its Elantra Blue nameplate for 2013, according to information Leftlane discovered on the EPA's fuel economy website.

Even though they are not on sale yet, the EPA lists fuel economy figures for an entire line of 2013 Elantras, including the recently-unveiled coupe. Hidden among those listings for models we know plenty about is a mysterious 34 mpg combined Elantra Blue (standard Elantras are rated at 33 mpg). That 1 mpg improvement in combined fuel economy comes from a similar 1 mpg bump in city fuel economy to 30 mpg. Both the Blue and the standard Elantra are rated at 40 mpg on the highway. With a new government-mandated window sticker design that emphasizes combined fuel economy over city and highway numbers, it seems logical that Hyundai might look to up its game with a special trim level.

Just what is this Hyundai Elantra Blue? We asked Hyundai representative Jim Trainor, who told us in an emailed statement:

"Hyundai is continuing to study the application of start-stop technology in our vehicles. Hyundai chose to certify a vehicle with start-stop to see the benefits in EPA testing, although plans to sell an Elantra Blue in the U.S. market have not been finalized."

That's not the typically vague commentary we're used to hearing from automakers. Trainor's statement reveals that the Elantra Blue features a start/stop system like that used on certain Kia Rios. Since start/stop systems on their own don't provide much help in EPA testing, which Hyundai has acknowledged before, it's likely that there are a few other changes designed to aid urban fuel economy on the Elantra Blue. Think throttle remapping designed to make high revs slightly harder to achieve and you might be on the right track, although it's hard to say for certain.

We wouldn't expect to see any major powertrain changes, even though the EPA's website mistakenly lists the entire 2013 Elantra range as having 2.0-liter engines. The 1.8-liter unit used in the 2012 Elantra has already been confirmed as a carry-over engine for 2013, so we'll chalk this one up to a mistake by the government. We do believe the government's inclusion of a six-speed automatic transmission, however, as that unit makes up the bulk of standard Elantra sales.

Would-be automotive historians might recognize the Blue nomenclature from a short-lived base model Elantra with a manual transmission and special gear ratios that was offered only during the 2010 model year. That Elantra was equipped exclusively with a five-speed stick-shift, which helped it achieve what now seems more like midsize sedan fuel economy: 26/35 mpg and 29 mpg combined.

Whatever the case, we wouldn't be surprised to see a little more news about the Elantra Blue at next month's New York International Auto Show.