Yes, fully agree that upto 20K miles the car is considered new.
Now there are few factors that cannot be ignore.
Performance wise, Pak. made or assembled engine’s life is not as good as European, American or Japanese Engine. Agree?
And so is the atmosphere and the quality of the Petrol, Parts & Filters.
So that’s why its wise to take the next step earlier rather than waiting for engine to cover its full mileage.
For example,
Performa 0/40 Super Synthetic, Company recommends to drive car upto 12,000 KM. but here we recommend to change it after 7000 max.
Performa 5/40 Fully Synthetic, Company recommends to drive car upto 10,000 KM, but here we recommend to change it after 6000 max.
Zic XQ, company recommends upto 12,000 KM, but we recommend 7~8K
Zic OW, company recommends upto 10,000 KM, but we recommend 5~6K
All because of same reasons as described above.
Hence the quality & workability of the components in Pakistan are not as good as compare with American, European or Japanese.
And also with passage of time there are different techniques to keep the engine healthy among which you are also using the one (of using liquid moly).