@nabeel.nagi
Dont ruin you Cultus by high rev. taking it to 4-4.5K RPM
Make practice of Shifting at 2K+, Maximum till 3K....dont go beyond that.
Your engine will start sounding like Roaring of tigers 
@all
Please use Total Fully Synthetic 5w-40 or 5w-30 or 5w-50 for Cultus depending upon Temp. of your area.
Preferable to use 5w-40 or 5w-50