185/60R14 tayar u use now? If you are, too bad nothing can be done to fix your problem. Technically, there's not much effect on your fuel consumption, simply because the diameter of the wheel has increased, your trip meter become less accurate. For the same amount of distance traveled, your trip meter will show less achievement, but that's about it. However, the heavy feeling is real. As the same engine/transmission you're using now needed extra effort to spin a bigger wheel. On long distance drive, the momentum will actually help you save fuel. The only problem, again will be reflecting lesser mileage on your trip meter and makes you think FC has gone bad.
KNN does not cure the root cause of slack in power. Less restriction would mean slightly more air flow allowed, hence you get slightly better response, but only limited to cooling weather/morning/night time driving. On the contrary, having KNN filter would also render in engine sucking hot air, hence in the afternoon/traffic jam condition, your acceleration will go the other way round, become numb and worst loss of power due to hot air fuel mixture harder to burn.
Same goes to pedal position adjustment, will not physically improve your acceleration. If you know grandma's radio has been tuned previously volume need to turn to level 8, now after adjustment at level 5 you'll be getting same loudness. For the love of God, our body sensor does not adjust like a machine, your brain still telling your body to put the right foot down and press the volume level to level 8 position, but in actual fact the radio loudness has been pushed to level 11. You hear louder sound from the radio on the same level 8 position and think grandma's radio has been upgraded? Its exactly the same like the car you've been driven the past few years now giving you better response with the same amount of gas pedal input. Let's put another example here:
Original volume with the scale of 0 ~ 10.
After adjustment, scale level become 0 ~ 13.
Actual result churn out will be as below:
Volume 0 - Actual 0
Volume 1 - Actual 1.5
Volume 2 - Actual 3
Volume 3 - Actual 4.5
Volume 4 - Actual 6
Volume 5 - Actual 7.5
Volume 6 - Actual 9
Volume 7 - Actual 10(overflow controlled, 10.5 not allowed)
Volume 8 - Actual 10(overflow controlled, 12 not allowed)
Volume 9 - Actual 10(overflow controlled, 13.5 not allowed)
Volume 10 - Actual 10(overflow controlled, 15 not allowed)

Do you get the idea? With or without the pedal adjustment, your car can only do so much. I'm not saying adjusting it is wrong. but if you ask me, I'd rather retard it to help save petrol

Because I know 1 thing for sure, if I need the speed, I'll just go pedal to metal, the same LEVEL 10 VOLUME I'll be getting

I think I get the concept, there's a limit to it compared to before. Like we depress 80% of the pedal to gain full air intake compared to previously where we depress 100% to gain full intake. But 80% to 100% constantly results in the same amount of air intake. Kinda reminds me of Vios where there's instant acceleration but it's only good up to a certain limit. Hope I'm speaking some sense.
I'm using Michelin 185/55 actually, lesser road noise and more comfort when cruising, just that acceleration has been compromised. Also, it's superbly true that this car is badddddd in traffic jams + hot days. It's like performance become 1.0L and most gear changes feels like a slight earthquake.
1. How much is a K&N drop-in air filter? Is it easy to install and maintain?
2. Is the TPSR (Throttle Position Sensor Re-Alignment) permanent or it resets after some time? Renautech and Osman Baba does the exact same thing right?
3. Does cleaning the TB reduce the jerkiness or helps in anything?