the possibilities for future power plants and/or many other components is pretty much wide open .... for the immediate future, Mark has designed his trike around using a a Toyota 1.0 KR1 engine and until he says otherwise, its pretty much locked in .... one of the things I look forward to is the various mods/upgrades that owners may be make in the future .... for our use, I believe his chosen engine will more than meet our needs/requirementsNow they make a smashing 1.5 triple that powers the fiesta ST and some of the smaller SUVs as well. It would be absolutely outrageous (and fun) in something like the BEX. Also having all that power would allow for some taller gearing for keeping great MPGs. I think that would be nice later down the road for a “hot” BEX.