15k miles means with their $10 filter, and all highway miles. There is no way I would do 15k on Mobil 1. 10k is easily doable all-highway with a clean engine in good condition and again, all highway, a top-notch filter, careful monitoring of the oil level, and no mechanical issues.

 

i still get worried about driving beyond 3k on one oil change. because ya knoe your oil filter can handle so much crap. with syn it cleans your motor better . just a though from me

 

Ok. Feel free to throw your money away.

 

Doing too frequent oil changes can actually be detrimental to your engine. Oil filters need to be primed, so to speak, before they actually filter most efficiently. A lot of people in the know sometimes fill the filter with new oil also before putting it on to prime the filter, let it soak, so it will be most efficient. That top filters out there like M1, Pureone, Wix, etc, an go many thousands of miles and will likely outlast the oil its filtering, though. But if the oil is running out of additives or collecting contaminants, the filter won't help much. Also, if your oil pan doesn't hold the capacity, going 15k is a definite no-no. Just cause an oil says it can go 15k doesn't mean your engine can. A lot of the German cars with 10k or 15k OCI also have an 8qt or larger oil capacity. Follow the manufacturer's OCI guideline unless you've done a UOA and know you can go a certain number of miles before needing an oil change. I change mine every 5k or 6 months, whichever comes first. My UOA showed great results and more life in the oil (M1 and Syntec) but for my comforts, I change every 6 months.

The problem is that there have been reports of oil leaks after switching to synthetics after using dino on high mileage cars. This happens due to the cleaning ability of the synthetic. For safety sake, you can always just use a high quality dino like castrol gtx. Or use a high mileage synthetic like the new M1 high mileage as that will condition and swell the old seals and hopefully prevent any leaks.

 

a little bit off topic guys, but i noticed everybody here is using 5-30 oil on the 100k+ miles engine. Isn't it bad to use a lighter weight oil on the high milleage engine..?? There's a few mechanic told me so, can somebody clarify this info..??

 

If your engine is still good, there should be no reason to change. Most people use heavier weight oil when their engine is leaking or drinking oil like no other.

In fact, I'm running on 5w-20 on an engine with 130k+ miles.

 

still use 5W-30, maxima has 165k miles, lexus has 191k miles...