I can garrentee this product
I have been using penrite oil since 1957 , used in tractors land cruiser rodeo , first bought a 200 ltr drum for 170 pounds , 340 dollers,that same drum used to last 3 years on the farm ,used the same oil in all the farm machenery, it leaves the motors clean and no sludge, and smoother running.
Never used synthetic oils before.
If you read my other reviews, you'd find that Toyota put the wrong oil in my once perfectly running Landcruiser and once it ran dry, lost much of its oil pressure and began burning oil.
I decided to try Penrite HPR 15W-60 after meeting a busy workshop owner who only uses Synthetic Penrite in his car and heavy diesel garage.
First key turn, oil pressure was back up (albeit not like before) and it stopped smoking out the exhaust completely.
Done 40,000kms in the past year just travelling Australia in some fairly harsh conditions and the engine has now reached 350,000kms.
Still runs like a dream and the best part is, even at 10000kms when it's time to change the oil, it comes out just as clean as when it went back in.
Have been using Castrol Magnatec on my Camry which has a full service history from new and has done 200,000kms and the oil turns black within a few hundred kms.
Switched to Penrite HPR. Runs quieter, smoother, and just feels healthier.