[dcb]

The sanguino is non-standard, even in arduino terms. You cannot use arduino standard and sanguino rightfully in the same sentence. I don't see any rationale for wasting peoples time with it here. Why not use a 168 which works, and not make self inflicted problems? If the 644 works, great, if not, what is the problem with asking the sanguino people? I don't think the folks working on this have time to chase their tails.

This isn't a pure development board, it has fuel efficiency feedback primary task, and it has already started to move away from arduino as a development environment because it tends to "get in the way" when trying to write a serious application, and creates too many distractions (i.e. unnecessary version dependencies and breakage and random CPU upgrade and support expectations).

I don't want to see this project turn into a "let's use an SUV sized chip because it would be so cool" type venture. You should really present an extremely good rationalle for introducing and expecting support for such a large deviation from the already working hardware. Othwerwise Arduino.cc or wherever the sanguino is officially supported is where you should start, instead of hijacking a project that is this far along.