If you all want to make the best way to treat an engine with GTO is to the succeeding steps. Treat engine with 1 bottle of GTO 250ml. let it run and use it normally for the next 5,000 kms.
1. After you reach 5,000kms. you may now drain your old oil... DNO NOT USE FLUSHING OIL TREATMENT! (The worse thing your engine can experience is to have that flushig oil inside it.)
2. DRAIN the old oil, using a high pressure air to push all the old oil out, let it drip to the last drop; Be sure to contain them in a resealable containers
3. CHANGE the filter with any original or genuine oil filter item.
4. POUR IN NEW REGULAR MULTIGRADE OIL;
5. When the engine is now ready; treat if with GTO;
6. Now you're good for another 10K to 15K kms. Once you reach the next PMS, replace your oil filter alone. No oil change is necessary, just add GTO again after the filter is replaced.
7. Upon reaching 40K km, you need to check your oil again, and replace it with fresh one, along with a new filter. Then repeat the GTO treatment. Just repeat this cycle for every 40K kms interval.