Mere pass alto 1000CC 2006 model hai i was also facing average and car taking off from the road at the speed of 120 km/h so i went to mechanic in lahore who claimed that i will raise your car average to 18/Litre and i was like laughing and saying inner me oh this is impossible but after tuning and engine work from that mechanic i went to karachi and i was shocked to see that my car is giving me an average of 16/Litre and i was very happy and immediately called my mechanic for saying thanks to give 16/litre but he was sad and said no average has to be 18/L but i still gave him a good feedback and one more thing is about the speed yes my car also trembling at the speed of 100 or above but that mechanic advised me to cover your steering into Electronic Power steering and i did and that cost me about 8500-Rs in 2021 that was cheaper and also gave me warranty of 6 months but its now an year i never take my car for any complain to them so after converting into Electric i realise there was no trembling and wasn't taking off even at the speed 140km/h which is the maximum speed for Alto 1000cc but still your foot and driving style matters i want to suggest everyone never learn driving from your brother sister or father etc always go for the driving school because they will tell the errors in you and tells u about the road signs, rules and regulations.
Thanks,