* Optimus Prime can
Superman fly! 
I say Superman Fly because it's not just any ordinary flying, he can actually fly into space which requires a
massive amount of energy. This is why rockets and shuttles have huge fuel tanks attached to them which break off during take off. Not even Megatron or Starscream seemed able to sustain long range high speed flight in robot mode, only in their jet modes. If Optimus Prime can Super-Fly, then why bother transforming and driving around places in truck mode? It's surely faster and easier to just fly everywhere. We see him driving away from Lockdown and Cemetery Wind... why not just fly away? When Optimus Prime was being dragged up by Lockdown's magnetic device, why didn't he try to fly away (it worked for Strafe, and he was only using winged flight!)? Why did Optimus Prime bother riding Grimlock? Why didn't he fly back as advanced reinforcements? There were just so many moments where he could've moved so much faster with flight rather than rolling or riding to his destinations (or away from enemies). And is this flight ability newly acquired or has he always had it? If it's the latter, then a LOT of other moments in the first three movies retrospectively don't make sense now. Why did Optimus Prime crash on Earth as a protoform asteroid? Why not transform to robot mode and
land? Why didn't he fly after the Ark and save Sentinel Prime when it got shot on Cybertron? Why didn't Optimus Prime fly to the moon instead of taking the Xantium? Ratchet could've come along later aboard the Xantium to retrieve Sentinel Prime and the pillars after Prime did a solo recon mission. Why didn't Optimus Prime fly away from Sector 7 forces in TF1 instead of running around in robot mode?
All of his fight scenes would've been different if he could've flown -- he wouldn't have needed to sacrificially combine with Jetfire in ROTF nor bothered to even have the Jetwing in DOTM. And the fatal jungle battle might've ended more favourably if he could've flown. It really felt like the writers wanted to have Optimus Prime leave the Earth in order to protect it - which is fair enough - but then realised that they hadn't conceived of an idea of HOW he would actually do this, so they wrote,
"Optimus Prime flies into space." It's like one of those, "a wizard did it," moments.
