Changing to Mobil 1

[misterp]

<div class='quotetop'>QUOTE(CompToyZ &#064; Jan 3 2007, 05&#58;25 AM) [snapback]78184[/snapback]</div>

...I also do not have a block heater in the truck and the engine has never even so much as lagged when starting. Even when it hit -29 Celcius. ...[/b]

DAMN - where do you live, the South Pole?&#33; That&#39;s COLD&#33;&#33;&#33;

Mr. P.

[Red03SilSS]

I am running mobil 1 10-30 synth. and havent had a problem.

[TxStVanWilder]

i run Penzoil 10w-30 full synthetic... have run the same oil since i was 17 basically.....

[Gordy M]

Many years ago, when I would rebuild my Corvette engine I would always use a petroleum base oil for the first 500 miles and then switch. Our local Corvette club had the chief LSEngine from GM speak about the Z06 engine three years ago and we asked him why GM quite using the base oil in the LS production engines. He said the build tolerence were much tighter and the quality of the metals were that much better, therefore, GM has no breakin period for new cars and trucks other than towing.

[sprayed99]

<div class='quotetop'>QUOTE(TxStVanWilder &#064; Jan 3 2007, 08&#58;39 AM) [snapback]78187[/snapback]</div>

i run Penzoil 10w-30 full synthetic... have run the same oil since i was 17 basically.....
[/b]

AHHHHHHH the real reason for the 14.9X 1/4 times is out now

I run mobile1 10 30 in the gibbs

and straight 50 royle purple in the 84

camaro also got mobile1 then it got purple always 10 30

[DamnYankee]

<div class='quotetop'>QUOTE(TxStVanWilder &#064; Jan 3 2007, 08&#58;39 AM) [snapback]78187[/snapback]</div>

i run Penzoil 10w-30 full synthetic... have run the same oil since i was 17 basically.....
[/b]

So whattaya think after running it for a year?



<div class='quotetop'>QUOTE(Jaw_Dropper &#064; Jan 10 2007, 08&#58;27 PM) [snapback]79199[/snapback]</div>

I paid &#036;65 for a oil change today to switch from Penziol to Royal Purple and I havent felt a difference.. Like they claim
[/b]

I don&#39;t think you&#39;ll really feel much of a difference, although I will say when I switched to AMSOIL it felt smoother. Probably my imagination.

Anyway, I like my AMSOIL, I like their testing, I like the protection they say it gives, and I like that I don&#39;t have to change my oil as often.

[misterp]

The reason that the OEM can get away with using synthetic oil on initial firing is because their cylinder machining process has evolved to such precision that complete ring seal happens in the first couple seconds of initial firing (during the factory dyno test). OTOH most automotive machine shops cannot achieve that level of near-perfect initial ring seal (many don&#39;t even try, regardless of what they say to your face) and the rings and cylinders must wear together for ??? miles until complete ring seal is achieved in the rebuilt engine.

The only accurate way to measure this is with a leakdown guage, on a new engine when leakdown has reached < 2% the rings have seated and then you can switch to synthetic oil. In lieu of a leakdown guage use petroleum-based oil for the first 1-2 changes (3000-6000 miles). IMO if you are serious about your engine you should own a leakdown guage, you can get one for &#036;75 (or less on eBay) and the knowledge you gain is invaluable; you can tell exactly what the condition of your rings & valve seats are with it.

re viscosity - viscosity is chosen primarily on the running clearances of bearings & piston skirts in the bottom-end, operating environment is a secondary concern. If you are using factory rod/main/piston clearances then you should be using factory recommended viscosity; if you are using clearances so loose it sounds like a Singer sewing machine underhood then straight 50W might be called for&#33; If in doubt then call the manufacturer of your pistons and ask tbem, they will be able to tell you exactly what viscosity will meet the needs of both the initial cold clearances as well as hot clearances of their skirt design.

Personally I prefer to use the lightest possible viscosity in my engine builds, so I use very tight (factory) bearing clearances as well as forged pistons that will expand to tight factory running clearances after they have reached normal operating temperatures (only takes 30-60 seconds). My favorite street oil in this kind of engine is Mobile-1 0W30, I&#39;ve run that in my SSS 50K-miles now and it is still silent on startup and readily makes 80psi at 5000-RPM. And in a performance/racing application where lots of heat is made I use Mobile-1 0W-40 (has more "staying power"), their 0W-40 formulation is one of the top 3 in the world regardless of manufacturer IMO.

Mr. P.

[CompToyZ]

LOL Vegas? Canada actually with a couple years in Anchorage Alaska. LOL it&#39;s gotten colder then that, in fact I worked outside in colder then that lol. I used to give my body tot he drilling rig Gods in northern Canada. They would shut us down at -40 though so it wasn&#39;t so bad lol.

[Ascrap2003]

What you can&#39;t do in any engine is go back and forth from syn to pet.
If you choose syn go with royal purple, amsoil or redline.

[Jaw_Dropper]

<div class='quotetop'>QUOTE(Ascrap2003 &#064; Jan 10 2007, 07&#58;27 PM) [snapback]79191[/snapback]</div>

What you can&#39;t do in any engine is go back and forth from syn to pet.
If you choose syn go with royal purple, amsoil or redline.
[/b]

I paid &#036;65 for a oil change today to switch from Penziol to Royal Purple and I havent felt a difference.. Like they claim