maybe make the engine slow down temporarily after using it, like fire up.
it is the only way i think you can nerf it without ruining its advanatages espeically considering it's a vet 1 ability. like giving it engine damage afterwards would make it useless for anything but retreating.
My personal opinion is:
I love Blitzkrieg ability, and I think its great reward for getting to vet1, etc.
But it should be used offensively, not as a 'get out of jail card'.
Disable ability once the tank's health goes under 25-30% health.
I think that would make it great ability
What do you think?
(engine damage after makes it a little bit to much punishment for not that much benefit really, in my opinion)