Synthetic oil question

[Dale]

I just put full synthetic oil in my truck; I mentioned it to someone and he told me that once you use full syn. you are not supposed to ever to back to conventional oil. He said if you use syntec blend, its ok to go back to regular oil, but if you use full syn., you are supposed to stick with it from now on.

I looked online for evidence of this, but came up empty. So I'm asking if anyone has ever heard such a thing? Just in case I end up buying reg oil in the future, I want to make sure its not a problem...

[aff]

Never heard that before Dale! Only problem I've ever had was putting Synthetic in older engines , They seem to use oil at that point, Guess because the synthetic's viscosity is so much thinner!

[theviceman]

my engine builder tells me to break the rings in on regular crude oil,and switch to synthetic about 3 weeks into the season to insure ring seating....something about synthetics being too slippery on the walls for the rings to seat.
i i dont remember hearing any scenereo like you mentioned,but it does sound possible with the differences in the oils composition.
i would call the manufacturer......or look up brad penn oil in bradford pa and call them for advice.....they have been nothing but pleasant whenever i called them with a tech question.
and they make a darn good racing oil.....


viceman

[highbankracin]

vadirt, it is okay to switch to synthetic and back to dino. Both oils are compatible.

Second, not all synthetic oils are true synthetics.
Take Mobil1, for instance. It's NOT a synthetic. It's a "super refined" dino oil. Oil makers are allowed to call "super refined" dino oils synthetic.

Amsoil, Red Line, Royal Purple, the racing synthetics are TRUE synthetics.

A synthetic oil is no thinner than a dino oil. 30 wt is 30 wt, regardless of oil type.
The synthetics flow better is the difference.
And the old story about engines leaking when using synthetics is a thing of the past. Oils and gaskets have been re-engineered to prevent this.

I ran whatever was on sale in a bike I used to have-synthetic one time, dino the next, and it had a wet clutch. No problems.

And synthetic blends are a joke.
To make a conventional oil a multi-weight oil, what do you add to make it so? Synthetics! The synthetic polymers they add to a 30 wt (or whatever wt) make it act as a multi-weight oil.
So, a 10W30 conventional oil is catually a synthetic blend.

Using synthetics in race engines is where I'll let dirtdevil sound off. He uses Royal Purple in all his engines and has had excellent results-and he used to get a name brand oil for free-and made the switch to RP.

dirtdevil, you wanna chime in here? !

[aff]

Might want to read this on Oils Dale. Goes into depth about viscosity and synthetics!! I see no problem at all with what your doing! unless you are putting it into a Older engine like I said!! You know what I mean Dale! " An Older engine" One that hasn't been engineered and doesn't have the latest and greatest Seals and Gaskets!! You know. An Older engine like I said!!

[highbankracin]

You'll have to go back 20 years for the symthetics to sneak past seals due to their engineering.

And viscosity is a constant-0 WT is equal to water at a certain temp.

30 wt dino is equal to 30 wt synthetic. They are the same thickness, or they can't both be 30 wt.

aff. you did a bad job of attempting to not respond to my post.

Plus, how about the link to what you are referring?

[dirtdevil]

My son had a 87 Monte Carlo that had sat for awhile. When we got it and did an oil change with some regular 10w40 Valvoline it had some start up smoke and developed a "drip" at the rear main seal and at the valve covers. The next and the rest of the oil changes done on that car were done with Valvoline High Mileage formula and the above conditions seemed to have cleared up. I would include something like that into the catagory of "older engine". Along with a vintage Chevy 265 that is in the 56 hardtop you found at the estate sale.

Now as far as synthetics; Mobil 1 was the cats azz for awhile, EPA and other regulations took away the zinc and that changed things. Not with just Mobil 1, but with alot of oils. The full synthetics today for street use, you can buy them at Wal-Mart or Auto Zone, are not the racing syns that we use in our motors.

Real racing syns are: Royal Purple XRP, Joe Gibbs, Brad Penn, Schafers, Torco and I have probably missed one or two. These oils still have zinc and the other nasties that the govt. don't like us to be around. If you are using a street synthetic and want to add the additives back in, which would really only be necessary if you are running solid lifters or turning some big RPMS, comp cam sells what is called a break-in additive that has the forbidden chemicals in it.

Viceman - What we have always done with new motors is fill them up and fire it up with NAPA straight 30wt non-detergent. Run it 3 or more "sessions" to get it up to 210 on water temp. (Most of the time we don't completely fill the radiatior to get it that warm) After cycling it like that, check for leaks, check the valve lash, drain the oil and give the drain pan as well as the return screen and filter a good look see. Add new Royal Purple XRP , a new filter and go to the track and turn it 8200+.

Portions of the above are sponsored by Royal Purple

[aff]

The old break them in like your gonna run them deal!! Thats pretty much how I broke mine in! Build them, Bring them to temp, change the Oil and take them to the track!