So i have noticed that if i drive like grandma i get awesome gas mileage but at times when i drive around town and speed up from stops faster it seems to get even better gas mileage.... so im really confused lol it should be the other way around whats up with it?

 

That is due to the fact that the efficiency map of an engine is somewhat like a topographical map of a mountain, usually with the top somewhere in the middle being as high as 37% maybe, and the outskirts (lowlands) being around 20% or so. Accellerating a little harder than grandma simply puts you closer to the top, as long as the accelleration lasts. If you really step on it then you go over the top, literally. If the engine didn't vary it's efficiency like this then it wouldn't matter how hard one accellerates accd. to the laws of physics.
An engine (& powertrain) build for high mpg is successful if it manages to put the top efficiency close to the RPM/MAP where the engine spends most of it's time.