Dude... My car has the same problem as your's. Heaviness. Along with that my leg pains when I really try to push the accelerator when the heaviness is felt. Before 15K service I had this issue now and then. After 15 K service, for the first 2 days there was a drastic change. I was happy that the problem is out of my car, but again the car feels heavy. The engine roars louder but no equivalent movement. I suspect two things 1. The A Pedal Sensor. I have been driving car for almost 15 years. Both Diesel and Petrol. The ' On touch of the Pedal' feel is badly missing. Being used to driving Indica Diesel and Santro, I control the speed only by touching the pedal with my foot and not flooring. It is only in my punto I flooring the pedal to get the speed I want. With that 15 yrs experience in subconscious mind, Still I do that touch, and wait 3 seconds to feel the car responding to it. I guess the Sensor or whatever which gives the Pedal position information to the ECU is not responding quick enough. 2. Some component in between the Engine and the Wheels that dosent all the power generated to spin the wheels. After the 3 seconds mentioned in point 1, I get some response from the car as if it is taking off, but actually it just responds and then struggles meaning the RPM increases and dosent make the car move fast. By this time the RPM shows 2200 - 2400. Now it is the time to upshift. I do that but after that the car still struggles and again touch - 3seconds- respond and struggle - roaring and goes on. In few minutes my leg starts paining. If I ignore the roar and go +3k rpm to upshift, it feels better but that is really not economical. I have always been unlucky when I ask some other to drive the car and check if they feel the same. Colleagues, fellow TFI'an , TASS Service engineer. When they all tested, the car behaved normally. But once when me and my colleagues were returning from mahabalipuram, my colleague drove the car from mahaballipuram to chennai. When we were near Mayajaal, he couldn't continue driving the car anymore due to leg pain. He said this is a serious problem, if it is undrivable on highways then this is too bad. May be we should swap the cars someday and see if the problem is exactly the same. So that we both can take the car to show it TASS. may be then they may get more serious on this issue.