Take a guess as to what will happen if someone might drive a Cruze Eco carefully? Actually, its been done; 64.4MPG. +27.1mpg over my average.
http://green.autoblog.com/2011/08/25...64-mile-drive/
That "point" can go both ways, but I can guarantee you that nobody will be getting 64.4 MPG out of a non-Eco. They chose the Eco instead of a 1LT, 2LT, or LTZ with a manual (which by the way are very uncommon) if not flat out rare.
If you want help making a solid rule, you have people here willing to help. You don't seem to be asking for help though; you seem to be repeating the same thing, that you won't add this as a separate model.
I get it, I really do, which is why I changed the wording in my last post from "new model" to "separate" and "differentiate." Is there any way to allow a separation between the Cruze Eco (+8.5mpg over non-Eco average over 151 vehicles), Cruze LS (only model with a 1.8L N/A), and Cruze 1LT, 2LT, and LTZ? All technicalities aside, you stated very clearly in another thread here that this is a fuel economy site (not a cost of ownership site), so for the purposes of fuel economy tracking, there are 3 types of "Cruze" that are different from each other.
Why hasn't an option been considered for trim level as a drop-down menu? You have it for engine - which for 95% of the population is useless and confusing. Will people really know the difference between "Flex L4", "Gas L4", and "Gas?" That information isn't even in the window sticker of a new Cruze and is more difficult to obtain for you than trim levels would be.
Sure, it would be more work, but am I the first one to come here with this kind of problem, and will I be the last?