Originally Posted By: irv
I'd like to see that. How many different brands of oils were tested?
He's tested three so far. Thread can be found
HERE
Originally Posted By: irv
As far as cleaning goes, you're right,
I just believed those companies that touted their oils to clean and to keep things clean are correct.
Figured if that wasn't the case, then lawsuits/false advertising claims would be rampant?
On here, however, I have seen some very clean looking engines using Pennzoil oils and others, so that is another reason why I recommended it and believed their claims.
Fair enough. All modern oils contain detergents and dispersants and all the major oil companies make some sort of claim regarding not only their ability to keep engines clean but "remove sludge other oils leave behind", which, as the OP is experiencing is primarily due to neglect and perhaps improper lubricant selection rather than a brand issue.
Originally Posted By: Castrol
Castrol GTX Double Action formula cleans away old sludge*, while protecting against new sludge formation, better than tough industry standards.
Originally Posted By: Pennzoil
This helps keep engines clean and responsive. In fact, Pennzoil® motor oil helps clean out sludge lesser oils leave behind and keeps cleaning all the way to the next oil change.
Originally Posted By: Mobil
Mobil 1 keeps engines running like new by providing superior protection against sludge and deposit formation. Mobil 1 can clean up virtually all sludge in just one oil change.
Originally Posted By: Valvoline
Advanced cleaning additives remove deposits and sludge from the engine. Through active deposit control new buildup of harmful deposits is prevented.
There's never been anything presented on here that Pennzoil, particularly their conventional oil, was/is any better at cleaning than any other comparable oil in the same grade with the same approvals. It's mostly BITOG lore that got traction and started getting repeated frequently.
You also have to remember that the additive company Pennzoil (SOPUS) uses is the same one Mobil (XOM) uses. The co-own infinium. So the odds of a product from one side having some uber-secret magic cleaning agent that isn't available to the other is basically nil.