Prabhakar,
Based on what you say in the later part, of the last post the best judge of condition of the oil is the Lube manufacturer. It is the Lube manufacturer that should justify or certify continued use of the same oil.
I managed a 2 year programme for extension of Lube oil life in an 18v32, Furnace Oil fuelled (<4% S) 10 MW Wartsila DG Set. In the year 2000, our team was the first to surpass the Indian record of 8000 hrs lube oil life on 80% plus load. This could not have been possible without the active support from Mr. Rao, Head of the Grasim Cements, DG PP team at Raipur. The oil was finally changed at 10,100 hrs, not because oil condition was bad, but the time coincided with Wartsila’s 20,000 hrs “Top overhaul” of the engine. The driver for the programme was the lube manufacturer (Castrol) and my team member Vishvesh Ranade.
The point I wish to make is, and what Bala also pointed out, Lubes contribute a bare 2 to 3% of the cost of the installation. The onus thus would be on the lube manufacturer or the user. To be fair, it is a combination of both.
In your instance, the lube is possibly a Servo product and IOC being a behemoth less likely to support your cause. However, if the grade is from a smaller MNC like Idemitsu, Gulf, Elf, Valvoline, Motul etc., pursuing the case will be mutually rewarding. You can also draw support from my friends in BharatShell U Diwedi - Tech Ser Mgr or Rajneesh Kadam, Sr Reg Mgr West. From within this forum, Franky Xavier’s Delo series may be a willing partner.
Hussam Adeni