Are "high mileage" oil "seal conditioners" needed?

[Ed_Flecko]

I have a 2004 Toyota Tacoma truck with the 2.4 motor and I recently changed from conventional "bulk load" oil to Mobil 1-Extended Performance 5W-30 oil. I was a little nervous because of all the horror stories I'd heard about oil leaks, but so far...so good. My motor runs fine, and no leaks!

Before I switched, I called Mobil and discussed which of their oils to change to and, no surprise, they recommended the "high mileage" oil because of the "seal conditioners".

I'd like to try a different oil at my next OCI, like the new Castrol Edge-Extended Performance, but I guess I'm wondering if I should be nervous about changing brands since my truck, after 1,500 miles on M1, doesn't leak? Is it safe to "assume" that if my truck doesn't leak on M1-EP that it probably wouldn't leak on another high quality oil? Obviously, neither of these oils are the "high-milage" varieties and therefore, do not have the magical "conditioners".

I guess I'm also wondering if the oils that have these "seal conditioners" are really effective and needed? Do they truly do anything beneficial and beyond what any other Brand X quality oil does or is it largely just another marketing idea to sell more oil?

Ed

 

[buster]

They are effective and do work. Engines that have run nothing but synthetic oil will generally not require the use of a High Mileage oil. One of the XOM sales reps said he switches his cars over to High Mileage oils around 50k miles.

Some engine seals are better than others. Some are more prone to leaking over time. If it's not leaking on M1 or HM oil you should be fine on any oil.

 

[Olas]

If its not leaking now, your seals and gaskets must be good. Changing to a different oil won't make good seals go bad or leak - some argue they expose leaks by cleaning crud that was sealing, but crud isn't supposed to seal, gaskets are!
But anyways, change with confidence

 

[geeman789]

All motor oil contains seal conditioners...

HM oils contain "more..." seal conditioners...

How much more is yet to be determined...

HM oils are also typically at the thick end of any viscosity range, and may contain more anti- wear additives, and are often not Resource Conserving or in compliance with the latest ( watered down...?) spec's. Think QS Defy for example, higher zinc, no starburst symbol period.

Some say that's a good thing...

 

[Dallas69]

If M1 is working good,why do you want to go to Castrol?
Don't get it.