I would never put any of that garbage into my engines. Use Mobil 1, which only costs slightly more than non-synthetics at Walmart, and be done with it. I have a car whose engine became notorious for sludging up. But I used Mobil 1 - which doesn’t sludge...and the engine is still pristine.
“I have a car whose engine became notorious for sludging up.”
V6 Toyota, perchance?