J_C
Explorer Addict
- Joined
- July 30, 2009
- Messages
- 6,073
- Reaction score
- 2,201
- City, State
- Florence, KY
- Year, Model & Trim Level
- 1998 XLT 4WD 4.0L SOHC
All major brand oils with a good additive pack, have some seal conditioner aka seal sweller(s). HM oil typically has more seal swellers. You only want enough seal swellers to stop leaks, maintain the same dimensions of the seals. More than that can cause the seals to become an excessive size and reduced density, making it then NEED the seal swellers more than ever, will wear them faster. It is not a night and day difference in wear, just a little, over the long term, but for that reason, I'd avoid HM oil if there were no signs of seals leaking, and at the start of a leak, I'd just substitute a few quarts of HM and ramp that up as needed, IF needed.I had been using Valvoline Semi Synthetic oil prior to going Valvoline full Synthetic HM. Your the first to report more detergents might be in the HM oils. Originally I thought HM oil had some O-Ring or Gasket restorative properties, similar to leak stop additives.
The oil companies don't like to admit this and have trained their staff to stop using the word sweller.
If a vehicle needs more detergent than in a major brand oil meeting the right API spec, it's more likely it needs the oil changed more often, not just switching to HM oil. On the other hand if the oil has not been changed often enough, I'd instead do a short change, run the new oil 1K mi then change it again, along with the filter, not try to break up a lot of sludge at once with a higher detergent oil, then leave all that circulating in the system (or clogging the oil filter till the relief valve opens) for the next 5K mi.