How can an engine oil's viscosity be shifted downward, preferably without adding something that interferes with the careful balance of chemical additives already in the motor oil?
So far I've seen that SeaFoam (from their website) says you can leave it in the oil and they don't use additives, all just petroleum distillates. Sounds good. Any other options? Kerosene, diesel fuel, pure low-visc basestock (if can be bought OTC)? Kreen seems too aggressive chemically to leave in. Ditto ChemTool. Looking for something that won't bother the additives already in the motor oil. Don't want to add much, maybe half quart or so to a sump. Any suggestions?
Goal is to thin an engine oil out a couple of cP at KV100, thats all. Winter use mostly. Also to use a 40 where a 30 is spec'd.
So far I've seen that SeaFoam (from their website) says you can leave it in the oil and they don't use additives, all just petroleum distillates. Sounds good. Any other options? Kerosene, diesel fuel, pure low-visc basestock (if can be bought OTC)? Kreen seems too aggressive chemically to leave in. Ditto ChemTool. Looking for something that won't bother the additives already in the motor oil. Don't want to add much, maybe half quart or so to a sump. Any suggestions?
Goal is to thin an engine oil out a couple of cP at KV100, thats all. Winter use mostly. Also to use a 40 where a 30 is spec'd.