What to upgrade?

[JuDomines]

I will have this choice to make very soon. I have to admit I rushed the university upgrades before they raise the cost with the upcoming update, which impacted my oil capacity. I'll give airstrip a higher priority probably, even though I'd have loved playing with the biplanes a little bit more, zeps look too strong to pass up.

 

[Eddie F1]

My Zeppelin is ready tonight - hope it's the 5* in one pass variety made by Samsung