i'm driving a hyundai avante with beautiful 17'inch rim and low profile tyres. Its a killer. But l notice thatit reduce my power and increase my fuel consumption. l need advise on what l should do to power it up and at the same time still able to make it fuel efficient? Pls help l do not wanna loose my rims..

Nothing is free. Generally more power = less mileage. Your best shot might be nitrous which gives you more power and leaves your mileage the same when you are not using it.

When standing side by side, do your new tire/rims measure the same height as the stock set did? You probably are getting inaccurate numbers since you changed the diameter of the tire. I'd have the speedo checked by a tire shop to see if it is measuring accurately. Bigger and probably lighter rims/tires should not reduce your fuel economy unless you really got much wider tires.