switching from regular oil to fully synthetic in a quad 4

[3X00-Modified]

Synthetic is MUCH thinner oil than conventional and in a variety of cars is KNOWN to cause leaks as it's able to "slip by" in places conventional oil won't. I've seen it, I've experienced it, and I know it. But , in the end it comes down to what you want to believe.....

I rebuilt my engine and sealed it properly and run 5w30 Mobil 1. My engine doesn't leak a drop. If done correctly even the slippery aspect of the oil will not cause it to leak unless your dropping it in a motor that is already quite tired on the crank or rear main seals...

Synthetic is just less forgiving than conventional, and honestly if its thin/slippery enough to do that to seals that were holding other oil back, just think how much better your overall oiling system is now working.

As Weba said, if you switch and it makes a leak, fix the leak.

[tvc3-gtz]

the slippery aspect .. isn't that viscosity? I'm not tech savvy but.. I know the chemical build is different, but honestly I change my standard motor oil in the GTZ frequently enough to render no need for synthetic use.. Honestly it's personal preference and when you take good care of a car and keep it maintained either one's use shouldn't be an issue...

[DTMAce]

Viscosity is the liquid's ability to flow through your engine parts at different temps. Technically, 5w-30 in dino or synthetic SHOULD flow the same, the difference as I understand it, the synthetic tends to be of a smaller molecule size, and can absorb more dirt per quart, withstand higher operating temps etc.

I guess to each his own. But having been around cars a lot, and having switched high mileage vehicles over to synthetic, I have not seen increases in oil leakages, or changes therein. So meh.

If you have a leak, it needed fixing anyway, as others have said. lol

[greyfox]

Ive heard allot about switching to synthetic causing leaks however i have not found this to be true. With older synthetics i have heard that they could cause the seals to swell and create a leak however i know this is not the case now. Mobile one even has a thing on this

"Myth: Mobil 1 will leak out of the seals of older cars.
Reality:

Mobil 1 does not cause leaks. In fact, new Mobil 1 was tested in dozens of industry standard and original equipment manufacturers (OEMs) tests to prove its seal performance. It is fully compatible with the elastomeric materials from which all automotive seals and gaskets are made. If an older engine is in good condition and does not have oil leaks, Mobil 1 provides the same advantages as when used in a new engine. ExxonMobil recommends taking measures to repair the leaks, then using Mobil 1. ExxonMobil also recommends following the automobile manufacturer's manual for the proper oil to use"

I have switched 3 cars with 100k+ millage to synthetic and seen an increase of +1 mpg minimum.