Fuel Economy MPG/KPG/KPL

[jtopiso_imp]

There are no limitations for hardware manufactured under the metric system anymore than the imperial system.

Of course! You can always use your own standards, or design a specific bolt for a particular need. That's what some F1 teams do, as well as aerospace industry (like airbus: they use metric) and military industry. But that's an expensive route.

Most racing teams in Europe end up with a mix: metric where they can, imperial where they have to. For example: most good quality swaged spherical joints used for suspension systems are aerospace standards, again, only in imperial... or hard/expensive to get (from airbus' suppliers).