I keep seeing ads for "High Mileage" oil. Is that really necessary for cars with more than 75k on the clock? I've been using various Mobil 1 synth's over the years (regular, or extended performance) and never had leaks or problems. The car has over 100k now.

Secondly, to those using the Mobil 1 Extended Performance oils. Have you noticed sluggishness with the engine? Everytime i go back to this particular oil, the engine just feels sluggish. It either revs slow or takes its time to reach the powerband. I've done this back/forth test between the EP and regular synth and can confirm it's not just "in my head".

Thanks, everyone!

 

Run regular Mobil 1 synthetic and you'll be fine.

 

I agree. The extended oil is made for engines that burn some motor oil. If yours is even burning 1 quart between oil changes, you should stick with the regular synthetic -- its better.

 

I think a dyno is merited at this point. But yes it is expensive etc, but I felt the same way with my A32. No problems as of yet with the good 'ol 03 w/~94k on the ticker now.

Runs like a dream, oil is cleaner than any other vehicle I've seen.

 

HM oils should be used when you detect a leak or there is excessive consumption. I have never used syn on my vehicle and it did develop a leak (rear seals) and when I switched to HM oils at 125K on the odometer, the leak stopped on my second oil change.

Leaks happen when varnish gets deposited on the seals and the varnish prevent the oil's seal conditioners from reaching the seals, which eventually results in the seals getting brittle and then oil leaks. Synthetics significantly reduce the deposition of varnish so the chances of have a leak with syn is remote.

If you don't have a leak/ oil consumption, stay with the present oil regimine.

 

Thanks for the responses guys. The car isn't burning oil and there's no leak that i know off. The only reason i've used the EP variant of Mobil 1 is to extend the intervals (Blackstone verified), but my only issue with the EP is that the car feels sluggish.

I'll likely just ride this out to 5k then switch back to the regular M1 synth.

 

Valvoline Maxlife synthetic is a highly regarded oil for Nissan engines. It has a robust additive package to clean seals to make sure no leaking occurs. For those that have leaks can try Auto-RX (http://www.auto-rx.com/) as it had worked well for many.

Nissan engines also like thicker oils so Maxlife is a perfect fit. Blackstone Labs does not show many good results with Mobil1 in Nissan engines. I would not use it.

 

Blackstone Labs gave my Mobil 1 "good results" after I drove it for almost 10 K miles. But then, the Mobil 1 that i'm using is older. There are reports (not confirmed, but out there) that Mobil has changed the components they use in Mobil 1 after losing the suit with Castrol about what components can be called "synthetic."

When I use up all of my old Mobil 1, I plan to go to Amsoil synthetic motor oil in my Max.

 

from what i under stand, it's no longer a group VI and now a Group III. Mobil1 does not want to admit this. A lot of BITOG members don't use M1 for this reason any more.