In all continuities, the Autobots and Decepticons were originally one race which split into two factions. In some, this was largely a civilian vs military split; others were a bit more ambiguous.
In many of the continuities, the Decepticons are capable of natural flight while in robot mode (or possibly more correctly levitation). By-and-large, Autobots do not share this ability. They either require jetpacks, or can only fly while in their Alt-Modes (as planes, rockets, spaceships, etc).
Since Autobots/Decepticons were originally one mixed group, it seems as though they should largely have the same feature sets and abilities. Flight/levitation would be useful to civilian Transformers, just as they would be useful to military ones.
We know that some Transformers have changed factions, including from Decepticon to Autobot, so the technology isn't exactly kept completely secret or hidden. If we accept that Transformers can be manually upgraded, it seems as though upgrading to provide flight/levitation capability would be extremely beneficial.
Is there any reason why this has not, or cannot be done?