I use Royal Purple in all my cars and trucks. Engine , trans., differential ...........

 

I use Mobil 1, but I've heard it's good to use: 1qt Lucas Slick-50 with teflon in place of 1qt regular oil when you go to change the oil.
Any experience with this anyone?

 

As per the owners manual:

Engine Oil Additives

Do not add anything to the oil. The recommended
oils with the starburst symbol that meet GM
Standard GM4718M are all you need for good
performance and engine protection.

 

Ive been using royal purple for about a year but im going to switch to amsoil or the new castrol edge that is out. I didnt really see any better improvement with the royal purple and as I keep researching the ratings seem to be going down. I try to keep up with the best product out and it seems like amsoil never dissapoints.

 

Ummm, no. Go back and do some more research/homework.
http://mysite.verizon.net/oldhokie/windyridge/oil.pdf
That's a pretty good site although it doesn't have the updated 2008 charts...that would be here:
http://www.infineum.com/information/...20-%202008.pdf

 

The first number refers to the grade of oil when it is cold (think winter), the second to the grade when hot. By industry standards these are reported for 40C (100F) and 100C (212F). A straight grade SAE 5 will have a very high viscosity when cold (most SAE 5 oils have a viscosity on the order of 60 cSt at 100F) but will thin out considerably as it heats up. A straight grade SAE 5 will have a viscosity of about 3-4 cSt at 212F. Compare that to a multiviscosity 5w30. It behaves like an SAE 5 when cold, but doesn't thin out as fast as it heats up. A 30 grade oil must have a viscosity in the range 9.30-12.49 cSt when hot (212F), or about double that of a straight SAE 5. So a 5w30 is the same as an SAE 5 at 100F and the same as an SAE 30 at 212F.

Trapp,
Your question is probably much more complicated than you recognize. And as mentioned above, knowing what you mean by "track" your car is key.

All API SM/ILSAC GF-4 30 grade oils are limited by the API to 800 ppm phosphorus. No mater what brand you chose, if it is an API AM/ILSAC GF-4 oil (and almost all 30 grade oils are), it has phosphorus limited to 800 ppm. This effectively limits the oils main anti-wear additive, ZDDP, or Zinc dialkyl dithio phosphate. You will more often hear people refer to the zinc in the oil, but effectively this phophorus level limits the zinc as well since it bonds with the phosphorus in the additive ZDDP.

In high stress situations, the oil really needs the ZDDP to help prevent serious wear and potentially bearing failure. As a comparison, the AMSOIL Dominator Synthetic 10w30 Racing Motor Oil has phosphorus on the order of 1424 ppm and zinc on the order of 1575 ppm.

The other factor to consider is the oil temp on the track. As the oil heats up, its viscosity drops. A typical 30 grade oil will have a viscosity on the order of 10-11 cSt at 212F. As that same oil heats up to 300F, its viscosity drops to 3-3.5 cSt, or about 30% of nominal. The two primary defenses against this, are to run an oil cooler (and even with that you may still see oil temps over 250F), or to run a 40 or even 50 grade oil which will have a viscosity nearer 10-11 cSt as it heats up to near 300F.

I feel that an oil's performance in these fairly demanding situations is indicated by its High Temp High Shear rating. Some examples that I pulled off the respective corporate websites this week:
AMSOIL Dominator 15w50 - 5.4
Penzoil Platinum 15w50 - 5.1
Mobil 1 15w50 - 4.5
AMSOIL Premium Performance 10w40 - 4.3
Penzoil Platinum 5w50 - 4.1
Mobil 1 0w40 - 3.7
AMSOIL Dominator 10w30 - 3.6
AMSOIL Signature Series 0w30 - 3.2 (API SM)
AMSOIL SAE 10w30 - 3.2 (API SM)
AMSOIL SAE 5w30 - 3.2 (API SM)
Penzoil Platinum 10w30 - 3.15 (API SM)
Mobil 1 10w30 - 3.14 (API SM)
Penzoil Platinum 5w30 - 3.1 (API SM)
Mobil 1 5w30 - 3.09 (API SM)

Note that the non-API SM AMSOIL Dominator 10w30's HTHS is much higher than all the API SM oils. Also note how much is gained by going to a 40 or 50 grade. For my 02 Z06 with a stock LS6 and an oil cooler, I see the coolest oil temps when running an oil around a 40 grade and I used the AMSOIL 10w40 for a few years. In my last two races, I tried the Dominator 10w30 and saw about a 10-20F drop in my oil temps, but I suspect my oil is now about half 10w30 and half 10w40 as I have a cooler and an accusump so an oil change really doesn't get anywhere near all the oil.

The downside for all of you - your owner's manual requires an oil meeting GM Standard 4718M, all of which are API SM oils and you'll note at the bottom of the HTHS chart above.

My advice: If your car is under warranty and you think you'll get warranty coverage if you lose a motor at the track, use the recommended oil (GM 4718M), but use a good one (my choice would be the AMSOIL Signature Series 0w30). If you are not constrained by the warranty, run an oil better suited to the track with high levels of ZDDP.

 

The statements in bold above are incorrect. Please refer to the following link for the temperatures for the winter rating IAW SAE J300:
http://www.infineum.com/information/...20-%202008.pdf

You'll note the temperature ranges from -10°C to -40°C (14°F to -40°F) for the two tests of the 25W to 0W designations. It use to be 0°F for all "W" ratings years ago but it has never been 100°F. A 5W oil is rated at -30°C and -35°C.

 

The "W" stands for "winter" not weight.

 

I saw this and since it was directed to me I was going to respond that I felt you were dead wrong but I see others more knowledgable than I have already done that...

I did a lot of research about 5 years ago and I'll still stand by what I read which is that the LS1 likes a higher weight (thicker) oil at temperature. I can only assume that the LS2 and LS3 are similar. Either way, I use the GC 0W-30 and I have my oil tested at each change and every time the tests come back with glowing results. Even after 6-7k miles the GC 0W-30 still shows more life left according to the TBN test.

 

Castrol edge 10w60 full synthetic. Use it in my 6L for the extremes in Australian climate. I don't know how you guys can run 5w30 and push the engine so hard. I spun a big end doing that, will never use it again. Proper big end and main clearances/ with SLP hi volume pump, oil 1/2L overfull and 10w60 edge with high film strength protects my engine.

http://www.castroledge.com.au/product/product_10w60.php

 

This post will surely generate a few raised eyebrows.

Actually, BMW recommends that exact oil for some of their engines and it's highly recommended for use in the ZF 6-speed transmissions of the C4 Corvettes interestly enough because of its' superior high film strengths at higher temperatures. In the US, BMW dealerships are the only place I know of to get it...they look at me kind of funny when I tell them I need it for my Chevy.

As for the 5W30 standing up to hard running engines, all I can say is the NASCAR boys use 5W30 in their 750 HP engines that turn 9000+ RPM. I'd say that's a pretty strong statement about the capability of that oil. In the end, run what works for you and don't look back.

 

Which Amsoil oil do you recommend for street driving?

 

Royal Purple has not been in business as long as Amsoil or Redline.

 

Wow Subdriver, that's good information! I'm currently using the AMSOIL SAE 5w30 (I'm not running my car on the track, strictly street driving), so I think I will have to try the AMSOIL Premium Performance 10w40 when it's time to change it, which is about 10,000 miles from now.....again, thanks for the detailed info!

 

I recommend the one I use in my daily driver 06 CTS-V (LS2): AMSOIL Signature Series Synthetic 0w30

Glass Slipper,
Thanks for the upgrade. I made the assumption (never a good thing), that since viscosities were reported at 100F and 212F, that is what they used for the grade determinations. Appreciate your upgrading me.

 

 

I use Royal Purple 15w-40 on my 78 Camaro Z28 with no problems. This is my second time using RP on my Camaro, but still not sure what I'm going to go with on my 74 Corvette.

 

I have had great success with Redline on my other car in the manual and rear end diff. The shifting is real smooth now and doesn't stick or jam.

 

I also use GC in my LS3 Vette and LS1 Firehawk. I have a stash of it from back in 2005ish when there were rumors of it being discontinued in the states. All the stuff I have is still the "green" stuff. My UOA's in my Firehawk have been great too over the years. I haven't had my Vette tested seeing I want to wait till I get some more miles on her. I figure I will start testing around 10,000 miles or so. By that time it should be pretty much fully broke in.


Like mentioned above, I stocked up when it was on sale for $3.99 or $4.99 a quart.

 

Mobile 1 15w-50 to keep the warranty in effect. Of course, it is a Lingenfelter 403 engine and that is what they require.