Report: Volkswagen to produce 260-mpg plug-in XL1 — Autoblog Green Well, what do you know? When Volkswagen decided to show off the latest version of its so-called one-liter car, the Formula XL1, at the Qatar Motor Show, we wondered out loud whether or not the German automaker would actually manage to put it into production. As it turns out, that's the plan, albeit at a very small scale. According to Automobilwoche (sub. req'd, via The Truth About Cars), Volkswagen will build 100 XL1s as a small batch of regular production machines... meaning they'll actually be offered for sale to the general populace. No word on what will power the production models, but the concept featured a two-cylinder TDI engine, electric motor, lithium-ion battery pack and a seven-speed dual-clutch transmission. All that fuel-sipping goodness is enough to achieve an astonishing 0.9L/100 km just over 260 mpg.