i have gli 2007. petrol millage is gud , all depends on ur way of driving, i get approx 14-15 km/liter , easily in city , secondly , on cng i have converted my car from toyota capital , got 60wl cylinder and its giving me 150-160 in city with, and 200-210 km on motorway and all these readings are 4 ppls with Ac on,
breaking is not that big issue, but yes , corolla needs ur intensions while driving at low speeds, like on 20-30-40 km/hr, i have experienced car slips most at this speed, rather than at high speed breaking, tires must be a big issue, better change them, i have As539 yokohama, 195-65-14, and they are working gud in it.
Regards