helo I am an engineer and have traveling daily between cites, I have anew sym jet 4 125 but it cant work with me enough because I have long transportation daily , it is good at city only ,and have low mpg I dont know why it is about 27.7 km / 1 litter (it is bad mpg ) and low ability to climb even small vertical curves, and low rate of max speed 90 km/ h. if there any develop for performance please tell me. whith alot of thanks