Fuel smell at the tailpipe and increase of engine oil.

I am facing two issues of my Japanese Prius v 2015, odo: 105k km.

Issue 1: I found fuel smell at tailpipe or behind my car when engine is on. No fuel smell in the cabin. Its increasing day by day. Last year the fuel smell was very little and only found when the car first start of the day. Mostly winter time it was profound but this year the smell is still found at tailpipe even at the evening when the car is started. My long fuel trim stayed at 6.25% when engine is on.

Issue 2: My engine oil is increasing in volume in the winter. At summer, it was not noticed. After 4 months, nearly 300ml oil increased. I removed it and finally changed the oil.

What is wrong with my car? Could you suggest the ways to fix these issues?

Thanks in Advance.

 

Yes, I mostly drive for short distances. In the highway, fuel uses remain more or less same.

 

Here not much cold. Rearly temperature goes down below 12 degree centigrade, now temperature is 22-28 Degree centigrade.

 

Actually my car has 4.2 L capacity. I poured 4L oil on it when changed old oil. Oil grew over full mark. nearly 2 mm over after full mark within 3.5 months drove only 1600 km.