I started a company in 1900 (easy mode as I'm new to this game) and things were going along fine until I went to build a new vehicle and none of the new engines which research was completed were on the list as options for building a new vehicle. I've researched and completed new 4cly, 6cly and 8cly engines but NONE are on the list as available for a new vehicle - it only shows the first two outdated engines from 1901 and 1905 and that's it - none of the newer researched engines are there and it's now 1918 and I'm stuck with outdated engines! I've tried modifying the old 1901 engine to see if that made any difference and after 8-9 months research it was completed but it too doesn't show up on the list as available for a a new vehicle... what's the deal!