How does M1HM compare to PHM? I am using PHM in my trucks engine and it runs so smooth one would think the engine is NOT running at all!
I'll assume you're talking about the Pennzoil Platinum high mileage since the conventional Pennzoil high mileage isn't in the same category as Mobil 1 High Mileage...
In what way?
From the research I have done on HM oils I was reading about more mechanics and ordinary people that like PHM for its additive package. Sure, M1HM is a full synthetic oil that will probably last 2 times longer than PHM, but it's the additive package in PHM that seems to make it somewhat better. Now, these facts are based on just a few articles and responses I read from mostly BITOG members. Some are from ASE certified mechanics.
Tig1, if you could please point me in the direction of scientific research of these 2 HM oils I would greatly appreciate it. Thanks!
Since additive packages and base oils are not generally public information, how do you know one oil is superior to another, if that's your way of judging?