Royal purple XPR 10w40 question

[Gilles]

Originally Posted by JFP in PA

Go to your local Wal Mart, buy the 5 quart containers of Castrol Syntec 10W-40, a better oil and sells for about $23 per 5qt container, and no shipping............

JFP; +1 on Syntec

I switched from the Mobil1 to the 10W-40 Syntec after reading good comments here.

Like it better than the M1 and I do feel a difference mostly upon start up, it seems to run smoother. This comparison was after finally installing the Pedro's sport engine mount (nice..!) and the reduced vibration with the Syntec was noticeable.

PS, However I paid $25 at Walmart for the 5qt jug...

[Daniel R]

I would really like to understand the difference between oil weights, benefits and drawbacks.

I understand the whole viscosity thing, and what the two numbers in the multigrade oils mean, however it seems there are as many men as opinions in this debate. I have heard people say that thinner oil is better as it squeezes into gaps more easily, especially upon start-up, and hence is a better lubricant. I have also heard the reverse. I have heard people switching to lighter weight oil as the car ages, and others the reverse. What is the absolute truth, if there is such a thing?

I remember switching from Mobil 5w-50 to Mobil 0w-40 and immediately noticing the engine seemed to rev more freely and cleanly, whilst at the same time my coolant temp was running slightly warmer. To a rank amateur such as myself, this is a confusing result. One would assume the engine feels more free which would imply LESS friction, but why the HIGHER temp which implies MORE friction?

If anyone could shed some light it would be great. I know there are many articles out there, unfortunately most of them written by hacks who are not mechanics or engineers, and are probably based on nothing more than speculation.

All info welcome, just please no oil wars!

Daniel

[violametallic-S-]

I posted a thread about Royal Purple 0-40. I tried it last summer and i switched it the next day back to Mobil 1. I experienced unusual smoke from the exhaust and then hesitation while driving. Im not sure if it was 100% the oil or not but i switched it the next day and it never happened again so......

[mts]

UOA's on Castrol Syntec 10w-40 have been quite good. Not going to argue that it's the "best" oil, but when the UOA's are good, that works for me.

[Cloudsurfer]

Big fan of the Motul, but man, not cheap!

[manolo]

+1 on Motul. I use it on motorcycles and my 986S. I've used just about everything they offer, from hand cleaner to tech grease to MoCool coolant. None of their products have ever let me down, but its definitely not the cheapest thing out there.

[jmatta]

This is not correct, wear occurs at startup with cold oil. Zero winter weight is supposed to be less viscous in colder temps, thus reducing friction.

Ten weight winter oil would by comparison have more viscosity which equals less flow, less flow equals more friction.

I'm not talking about cold start up wear...I'm more concerned about the thin oils ability to hold up under high temp conditions; i.e. shear. The base stock is just too thin and does not provide adequate protection under heat.

Run what ever you like...it's your engine.

[941MXVET]

Originally Posted by Daniel R

I would really like to understand the difference between oil weights, benefits and drawbacks.
All info welcome, just please no oil wars!

Daniel

Daniel,

If you'er interested in learning about the different properties of oils, and various lubes, check out 'Bob is the oil guy.com' http://www.bobistheoilguy.com/forums/ubbthreads.php


Lots of good info, sure there's some B.S. too, but one can usually figure it out!

From what I understand group 5 base oils (polyoester) was developed and patented by Dow Chemical. Since they still hold the patent (IIRC) group 5 oils such as Red Line and some Motul lines cost quite a bit more. I don't mind paying up for it, but that's just me.

[lizBox]

Quote:

"Go to your local Wal Mart, buy the 5 quart containers of Castrol Syntec 10W-40, a better oil and sells for about $23 per 5qt container, and no shipping............"

Originally Posted by JFP in PA

We have 5 wal-marts in my town and none sell Syntec 10w-40 in the 5 qt jugs. Only 5w-30. Also went searching to many napas, auto zones and advanced auto parts. Same story.

Finally an auto zone guy offered to sell me the 10w-40 qt containers at the same price as the 5w-30 jugs ($28.99). Worked out to be $5.80/qt. More than I wanted to pay but cheaper then the $7.49/qt

Changed the oil and washed the Boxster today and took her for the first ride since Halloween. Seems so much faster now.