score:7
The limits are exactly the same for all EU countries, since they're in a single market and cannot set their own rules when it comes to imports from non-EU countries. Therefore for Lithuania (and all other EU members) the limit is as following:
In any means of motor transport, the fuel contained in the standard tank; and
a quantity of fuel not exceeding 10 litres contained in a portable container.
Note that this only applies to non-commerical imports, which means you're not allowed to resell this fuel after crossing the border.