Synthetic VS Regular Motor Oil ??

[shrinz_4]

01 QX4, 98K

I recently switched over to synthetic mortor oil in my QX4. I spoke with a technition at the Infinity Dealership in Madison and he informed me that it is ok to use synthetic in vehicles that have higher miles.

He also mentioned that it is really bad to switch back and forth between sythetic and regular oil and that once you start using sythetic, you shouldn't use anything else.

Has anyone else heard about this, and should I now continue to use synthetic?

[SixGuns]

Ok, basically, synthetic oil holds up better under harsh driving, cleans your engine better, and generally lasts twice as long. I, personally run synthetic in mine. The answer there is yes, you can run synthetic in high-mileage engines. However, if you're seals are leaking, and you don't want to do a rebuild, consider high-mileage conventional oil. And no, you can't switch back and forth - because the seals become conditioned to the syn, and when you go back to conv. they have the chance of blowing out, 'cause they will shrink and crack without the additives. Now you CAN switch back to conventional, but you have to do an engine flush. Which is a PITA. And a nice waste of oil. So...If you're running good oil, leave it that way. And change your oil-changing regiment to 6,000 miles with a filter change at 3. Just watch your dipstick...make sure you're not burning oil...you may not notice at 3k, but after 6...yeah, you might have burned a couple quarts.

[shrinz_4]

Thanks for the info. I think I am going to stick with SYN.

[Buzzman]

As stated above, don't be switching back and forth.Once you go synthetic, you should stay with it.

[dillonstr8goodz]

Hello,

I'm new to this forum. My dad got his Pathfinder in 2005 with 110,000KM. It recently got passed down to me late last year. I'm currently trying to maintain it and bring it back to life. He has been using synthetic oil for quite sometime now. I'm not sure of the brand. My question is, the vehicle is now approaching 316,000KM, is using Mobil 1 Synthetic Oil and Mobil 1 Oil Filter going to help much in keeping it in the long run VS the brand my dad uses? I plan to modify this vehicle and keep it as long as I can.

[Towncivilian]

Unless you plan on extending your oil change interval beyond around 8k KM, there is no benefit in terms of reduced wear over a conventional oil in the proper grade and API specification.

[skiski329]

I have a related question, iv'e been running synth for years and took it to the mechanic because there was a seal leak. They took off the top of the engine and replaced the valve spring gaskets after they tracked the leak to there. they had to pour oil to find the leak, and they changed the oil after they were done, and of course i write the next milage to oil change and "mobil 1 full synth" on my sticker when i change the oil my self. and what do they do... they change the oil with regular oil. now it's coming up time to change that oil and i'm not sure if i should go back to synth or regular. i'd prefer to go to synth cuz when cost co has the oil on sale i stock up and it ends up being cheeper then regular oil. Any ideas?

[Towncivilian]

If you can find synthetic oil on sale and its price rivals conventional oil, I can't see a reason not to use it. But if you don't extend your oil change intervals past 5-6k miles or so using conventional oil, using synthetic oil (that you pay full retail price for) is a waste of resources and money in my opinion.

[Slumpert]

The logic side of my brain calls the whole switching being a issue as BS.

Synthetic does not have the organic compounds it that "break down" with exposure to heat and combustions gases.

I do agree manufacture may put aggessive additives into synthetic oil that would potentially "break down" organic waste.. Heck I need that process to help clean up my gunked up engine, but so little of that would still be left active and then greatly dilluted on a first oil change back that I don't see it causing a friction issue.

And I call BS on anyone who thinks that "Gunk" will keep the engine from leaking.. I have crazy gunk in my engine and it leaks quite nicely.

[zach7685]

I will say after 167,000 miles regular oil not a single drop of oil then 10,000 of synthetic leaks every where.... waiting for my buildups again XD