Yes, Valvoline is dirty or it becomes immune to its self.
My Father-in-Law's 1998 Dodge Caravan 3.0L (98,000 mi.) has used nothing but Valvoline 10W-30 its whole life. He has always changed the oil & filter every 3,000 mi. without fail. The last 5yrs I've changed the oil for him and I noticed the oil looked darker but looked real good...color wise. His dipstick was dark and looking inside the filler hole was dark with slight areas of light sludge...I chalked this up as him being a short tripper type.
3500 mi. ago (I pushed his OC to the limit..hehe) I pulled a trick (didn't tell him) and used QSAD 5W-30
This QS started getting dark after 700 mi. I changed the oil today and it was black as tar and thick...wow ! The dipstick is shiny now...double wow !
What's up with Valvoline ? why couldn't it do this cleaning ? Nothing has changed in his driving habits.
BTW, this OC today I used Pennzoil HM 5W-30 I'm going to see how much more cleaning it'll do.
My Father-in-Law's 1998 Dodge Caravan 3.0L (98,000 mi.) has used nothing but Valvoline 10W-30 its whole life. He has always changed the oil & filter every 3,000 mi. without fail. The last 5yrs I've changed the oil for him and I noticed the oil looked darker but looked real good...color wise. His dipstick was dark and looking inside the filler hole was dark with slight areas of light sludge...I chalked this up as him being a short tripper type.
3500 mi. ago (I pushed his OC to the limit..hehe) I pulled a trick (didn't tell him) and used QSAD 5W-30
What's up with Valvoline ? why couldn't it do this cleaning ? Nothing has changed in his driving habits.
BTW, this OC today I used Pennzoil HM 5W-30 I'm going to see how much more cleaning it'll do.