I have a JDM Vitz, 2010 model, 1L, which I bought almost six months ago. It was driven 63000km outside Pakistan, confirmed via an official auction sheet. I've driven it over 6000km now. I have changed oils only twice in this duration. The first time, a certain 0w Shell oil was used (the dealer serviced it for me initially). The next time, I used Zic 0w. The car has been running fine so far. I put on new Dunlop SP Sports 703 tyres as well when I bought it. On the second service, I got air filter, oil filter and cabin filter replaced with second copies one from a Caltex service station.
However, since winters started, I have started feeling a vibration on the "floor" of the car. I can feel it on my feet. It's not on steering wheel or anything, but on the feet. I am trying to find out what may be causing that. It feels as though I can feel the road on my feet when I'm trying. It's not there all the time. There are times when the car is running very smoothly and I don't feel it, but other times I can feel it very much.
The car overall vibrates once in a while in idle. I was reading an English manual for 2010 Yariz, and it said that the car may vibrate for a bit in idle, which is normal. So, I've overlooked that. But I don't know the reason why I feel the vibrations on the floor. The tyre pressure is fine too.
What do you think could be the reason?
Any help would be greatly appreciated.