Because it is composed of low-boiling solvents, Berryman B-12 Chemtool Fuel Injector Cleaner (part #0116) will have no LASTING effect on any property of engine oil.  Instead, it will attack sludge and carbon in the crankcase and allow these contaminants to be dispersed in the oil.  After the engine has idled long enough to hit operating temperature—usually only 5-10 minutes—then solvents will be almost entirely boiled off and the vehicle can be operated normally.    At that point, if it’s not already time for an oil change, then a drop or two of “before” and “after” engine oil should be compared to see how much color from contamination the oil picked up.  If the crankcase was particularly dirty, then the oil may need to be changed regardless of where it is in a normal change interval.