no problem.
20w50 is a very thick oil. every one in the market wants to use it without any logic.
i personally tried it, found the engine becoming very less responsive, (engine ghut raha tha)
thinner oil will always give better fuel economy. synthetic oils are expensive, and i dont recommend using in an old car with unknown history. change your oil at max 4000km
switched over to caltex delo gold about 40,000 km ago, and its been working fine.
why people generally say to use 20w50, is because old engines have a lot of wear. but this wear only comes when the engine is run out of factory specs.
using direct fan/no thermostat, no coolant, non timely oil change will reduce engine life. thick engine oil may cover the wear, but not for long, because the damage is already done.
if you have not done so already, I highly recommend you do the following
1) Brand new thermostat valve
2) properly working thermostat switch for your radiator fan. your fan must only turn on when engine reaches operating temperature. this is key to long engine life.
3) 50/50 mixed, good quality coolant. easiest to find is zic green coolant, can be ordered online. caltex concentrate coolant can be found at caltex shops, it must be mixed in 50/50 ratio with distilled water.
4) nice clean radiator, and rust free hoses. you can do a radiator flush. method can be found on other threads of this forum.
