I don't suppose it's a 140/80 - 18?.
Nope, that's definitely not it.
I just searched and found the information in the wheels and tires thread: www.elioowners.com/threads/wheels-tires.1683/
Last year we were told that the tire sizes EM and Cooper were considering was either 135/70R15 or 135/75R15.
From a little research on tire-size-conversion.com/tire-size-calculator/ we discovered that the more commonly available 145/65R15 is close enough in size to the EM size that if needed it should work just fine as a replacement.
As compared to a 135/70R15 the 145/65R15 is actually the same size diameter tire except it is 0.4" wider.
As compared to a 135/75R15 the 145/65R15 would about 0.6" smaller diameter while being 0.4" wider.
The tire size question would likely be a very good question for someone to ask if they get a chance to do so at the New York Auto Show.