High Mileage Oil, New Car?

[CATERHAM]

Originally Posted By: Youthanasia
I drive WOT almost all the time, just a bad habit... and with a turbo I figured 0w-40 would be better than 5w-30. I didn't want to buy it cause it's HM, it's just the only 40w Mobil 1 that walmart carries in my area and it's $26 for 5 qt jug

Okay, since your into the boost a lot of the time I'd siggest installing an oil pressure gauge (assuming you don't have one already).
This very useful device will tell you amongst other things how thick of an oil you actually need to run. In all likelyhood, unless you track you're car you'll find you don't need to run a 40wt oil, even a 0W-40.

 

[Boss302fan]

Mobil 1 HM oils are excellent motor oils and have really good add packs. I have used them in newer low mileage vehicles and they preformed great. I would not hesitate to try Mobil 1 HM 10W40 oil for a 5K mile OCI... Great oil for your application.

 

[CATERHAM]

Originally Posted By: Boss302fan
Mobil 1 HM oils are excellent motor oils and have really good add packs. I have used them in newer low mileage vehicles and they preformed great. I would not hesitate to try Mobil 1 HM 10W40 oil for a 5K mile OCI... Great oil for your application.

In a new car it really makes no sense. Besides the worst part of M1 HM 10W-40 is it's low VI vs the high VI of M1 0W-40 assuming you even want to run a heavier than spec' oil.

 

[Bamaro]

A few posts here say high mileage oil is thicker than regular. How is a 5W-30 (for example) high mileage thicker than a regular 5W-30.

 

[Garak]

Sometimes, they're thicker, but still, obviously, within the range of a 5w-30. Same thing with HDEOs. A 10w-30 HDEO might be a tad thicker than a corresponding 10w-30 SN/GF-5 PCMO.

 

[veryHeavy]

Originally Posted By: CATERHAM
And yes it is not advisable to use a HM oil with it's higher levels of seal swell in a new engine that doesn't require it. You'll potentionally shorten the seal life.

Why? How does that happen?

 

[Garak]

This debate has been going on in a few current threads right now. Why dig up a several year old thread on the matter? Back then, most HM oils weren't ILSAC approved. Today, the situation has been reversed. Non-ILSAC HM oils may not comply with seal compatibility specs (although there's no reason that they could not, either). ILSAC HM oils must comply.

I've heard of people having leaks return after ceasing HM use. I've had some HM oils handle leaking better than others (my personal experience was with a non-ILSAC oil being better at it than an ILSAC HM oil). But, I've never seen anything credible about a HM oil damaging new seals by overswelling or overconditioning them. I suppose it's possible, but with an ILSAC oil, I'd never be concerned.

Put it this way. I wouldn't hesitate to use MaxLife 5w-30 dexos1 in a brand new GM vehicle. GM has certified it for that application, so there's really not much more to ask for.

 

[aquariuscsm]

Valvoline's page even says Maxlife can be used in new cars.