When to use High Mileage Oil?

[wemay]

If an oil is certified SN and even GF-5, it must meet usage requirements of all oils meeting the same specs, and currently, most HM oils do. Every additive within a spec must remain inside an approved range. Although the elastomers (conditioners) are increased for HM oils, they too must fall within this range to be certified API SN.

You can use these oils from new.

 

[ka9mnx]

Originally Posted By: wemay


You can use these oils from new.


^ Yep...

 

[JBinKC]

I would only consider HM oil if you have an oil consumption issue and used as a very last resort. It's best application is for a small leak that you are unwilling to repair.

My major complaint of HM oil is its much more challenging to find discounted more than 50% off of retail and your vehicle may develop a leak if you decide to switch back to regular oil.

As an example my 2006 DGC in an OCI used to require 3 make up quarts now it requires 5 because I now also lose 2 quarts from a leak.

 

[SHOZ]

I went to HM 5w30 M1 in my Hyundai Accent at around 140k miles. It always burned some oil since new, never leaked any. But the oil consumption has gone down to about a 1/2 qt per 7500 mile OCI from a qt every 5k OCI when new. Most oil had been M1 0w20 over it's life.

No problems with the oil filter gasket going gooey.....

I have take old OE gaskets and reconditioned them. Starting out with hard gaskets, I soak them in lacquer thinner for a while, testing to see as the swell and become pliable for the time in the thinner. Too long and they may fall apart or tear easily. Then soak them in oil for a day. Generally they come out almost as good as new, defiantly reusable. The thinner pulls the carbon out of the gasket and turns black.

 

[ejes]

I use it from the get-go anymore. The brand of synthetic I use most commonly costs the same whether it is the regular or HM flavor, so I just go with the extra additives of the HM. Works just fine.

 

[Broo]

Currently, my fleet of 5 vehicles all use high mileage oils. Mostly due to age rather than mileage.

The 3 "modern" ones (12 to 14 years old) get Mobil1 HM.

The older ones (>30 years old) get Castrol GTX HM since I can't get M1 HM in 10W30 flavor unless special ordered (and special order = no rebate ever applies).

Except for the oldest one, none had leaks. I just believe it's better to be safe than sorry. The oldest ones still leaks using HM oil, just a bit less.

My very first car I used regular Castrol GTX all its life (17 years). It went on to a pretty high mileage for its model until a seal broke somewhere and eventually ruined the engine. Maybe if I had used HM oil I could have gotten a longer life out of it.

 

[oil_film_movies]

Originally Posted By: wemay
If an oil is certified SN and even GF-5, it must meet usage requirements of all oils meeting the same specs, and currently, most HM oils do. Every additive within a spec must remain inside an approved range. Although the elastomers (conditioners) are increased for HM oils, they too must fall within this range to be certified API SN. You can use these oils from new.
That's true. All the SN, dexos1, 229.5, A40, etc, whatever specs an oil meets, requires the oil to be tested on a number of different kinds of seal materials to make sure they don't swell or shrink them too much. This is a fact that contradicts all the hunches & guesses from some people on this thread making bad assumptions. Bottom line: If any High Mileage oil you're looking at meets the spec your engine needs, then it will treat the seal materials properly from a swell & shrink standpoint.

 

[Mackelroy]

Originally Posted By: SHOZ
I went to HM 5w30 M1 in my Hyundai Accent at around 140k miles. It always burned some oil since new, never leaked any. But the oil consumption has gone down to about a 1/2 qt per 7500 mile OCI from a qt every 5k OCI when new. Most oil had been M1 0w20 over it's life.

No problems with the oil filter gasket going gooey.....

I have take old OE gaskets and reconditioned them. Starting out with hard gaskets, I soak them in lacquer thinner for a while, testing to see as the swell and become pliable for the time in the thinner. Too long and they may fall apart or tear easily. Then soak them in oil for a day. Generally they come out almost as good as new, defiantly reusable. The thinner pulls the carbon out of the gasket and turns black.


I have two vehicles Rav 4 and chevy colorado, both 150,000 miles, neither burn oil. This on 10w30 Valvoline dino oil.

So I ask, what did all that money spent on expensive under weight oil do for you in comparison?


Just askin