Lab test would be an extreme measure for checking oil performance or health on an alto, although the lab test also start with comparing the sample color with that of fresh oil, any unusual smell as burnt smell might indicate towards overheating, visual contaminations, metallic debri , slug particles etc. These indications can provide fair idea about oil condition to make a reasonable judgment, Another telltale sign is the engine noise and performance after the oil change, if u r feeling a minute improvement in performance and decrease in engine noise then the oil change was due. else u could have driven a few hundred Kms more. Anyways, it all depend upon personal judgment, i wont go for CRP labs for a simple fever, instead will start panadol.