MRDZR1

Well, it could be a few things. Maybe the type of seals use on the LT5 that wasn't performing or compatible well with this type of oil (leaks?), durability testing not finalize with this oil type? Or just the increase in HP that was introduce in '93 that called for a better product? Or the fact that they wanted to do a running change and use the remaining oil inventory they had in stock for this engine? Someone know the real answer but probably not on this forum.

As for the Nascar sponsorships comments,
Let's not forget that money run this planet and not always comment sense! So....!

glass slipper

Ummm, I never stated a reason for the '92 LT5 not using synthetic like the LT1. I proved it wasn't a matter of convenience and that was the only thing that paragraph was about. I also reiterated why 10W30 was used in the '90-'92 LT5 (less VII than 5W30) and that was it...I hope you didn't take that as my "reason". Seriously, what would less VII in 10W30 non-synthetic have to do with not switching to synthetic oil. Either my writing skills are terrible or you're having problems comprehending...or maybe a combination of the two.

You are correct that neither one of us could explain why the '92 LT1 used synthetic and the '92 LT5 used non-synthetic and I would never make a statement to that effect and claim it as fact. Since I didn't wager a guess, I'm certainly not "flipping out" over a "different guess". Personally, I don't care why they waited...it is what it is.

glass slipper

I don't think this has turned into a Mobil 1 vs Amsoil debate. I learned the '90-'92 LT5s use 10W30 oil and other people are learning things with the "sidetracking" so please don't think you have to jump off this thread. One thing that has come out is high ZDDP levels aren't important in the LT5.

Nobody here has said anything bad about Amsoil oil, the main beef is with their marketing. You're "conclusion/hypothesis" about Mobil 1 in your CTS-V causing sludge in one year and 10K miles, while technically is your opinion, there are people that read it as a statement of fact and come away with a negative feeling towards Mobil 1. There are other people like me that read it as BS and imediately get turned off from Amsoil. Let Amsoil stand on its own as the good oil it is, you don't have to "bash" other manufacturers with ridiculus sludge claims...the fact that you're a mechanical engineer makes it worse. I use Amsoil gear oil in my Mercrusier Bravo outdrives that I put 600 HP through just so you know I'm not an Amsoil hater. Like many other people, I'm just in search of the facts.

WydGlydJim

Well, I'm using Amsoil, but not what Marc recomended, but rather the best oil recommended from Amsoil site, and my dealer for the '90 ZR-1. I assume it has the levels of ZDDP for the older cars.......Maybe Subdriver can chime in here.........this is my choice.

SSO-QT

jimmac28

here's a good forum for oil, if anyone is interested.

http://www.bobistheoilguy.com/forums/ubbthreads.php

Aurora40

I fail to see how you've proved or disproved anything, but I apologize for the choice of words about "flipping out".

C66 Racing

GlassSlipper, thanks for the comments. Wasn't really your comments I was referring to, it was xlr8nflorida that seemed to be bothered by the AMSOIL comments and I didn't want to inflame him. Understand your points on the sludge, but as I'm the one that took the sample, I'll stand by that I didn't contaminate it.

WydGlydJim - dropped you a PM, but short story is that the SSO is subject to the 800 ppm API SM phosphorus levels. If you subscribe to the camp that believes that the LT5 needs higher levels of ZDDP, than this isn't the oil for you. If you believe that modern oils with better basestocks than existed in the 90s (understanding that that is a gross oversimplification of the differences between API SG and API SM) don't require the extra ZDDP, then the SSO is a very good oil. As indicated above, I used it in my CTS-V and saw very good wear numbers.

glass slipper

That's an API SM rated oil meaning it's limited to 800 PPM for zinc and phosphorus which isn't the same level as the older cars. I can't find anywhere on Amsoil's website giving that kind of info like Mobil 1 does so I don't know the exact amount. But don't worry as your dealer is steering you in the right direction...in my opinion anyway.

Edit: I was writing as you were posting Subdriver...we pretty much said the same thing though.

dallas916

And of course, if you dare to use the Mobil 1 15-50 like I do you automatically get the higher ZDDP levels. Yeah, I know it's goo compared to 0-30 watchmaker oils, but it does reduce my consumption on the long highway runs I (used to) make.

But that's another "old" issue, and since mine sits in the garage for all but a few dozen miles a year now, I guess it's moot.

MRDZR1

Wow! 0w30, 5w30, 10w30, 10w40, 15w50, Amsoil versus Mobil1 war, etc... What about the other brands? I've started this thread with RedLineOil, but there's also Lucas? Royal purple? The Green stuff? Does anyone have data on those?

Martin

PS: The last time I've used Amsoil in my kart racing engine it blew up after 15 laps, the piston welded it self to the cylinder wall!

LEADFOOT_

Wow, I love these debates. Seems like we see at least one every month. Once they get started they pick speed and they are hard to stop!

ZR1Rob

I've always used Mobil1 in the crankcase and rear end, castrol 60W in the trans. Now I use Royal Purple in the rear, but still use Mobil1. Not trying to convince anybody, just putting this down so I can read it again in 10 years.

pantera1683

Anyone use Valvoline VR1?

http://www.amazon.com/Valvoline-VV20...6315458&sr=1-1

They have a buy one case get one case free deal going on right now.

Buy One Case, Get One Free via mail-in rebate Mail-in offer. Special conditions apply. See complete rebate details. Offer expires July 31, 2010

http://classic.valvoline.com/qrz591d...p?rc=DE64D258D

glass slipper

No, probably never will even with the rebate. It's not synthetic, doesn't come in 0W30, and has too much ZDDP for me. Some may like it so thanks for posting.

PS It's also too expensive even with the rebate. Just another company trying to cash in on the ZDDP hysteria.

pantera1683

They make a VR1 synthetic in 10w30, it's just hard to find.

That's interesting, I thought the LT5 would benefit from higher ZDDP. Wasn't it designed in the 80s when engines used ZDDP for its antiwear characteristics? Also, doesn't Haibeck preach that the LT5 benefits from ZDDP. Lastly, some guy just posted on the registry that his Z had cam issues, I believe a bearing but I'm not sure exactly.

Maybe LT5s don't need that much ZDDP but I think I will trust Haibeck's opinion on this one.

PS: With all due respect do you have any references or expertise for your "ZDDP hysteria" opinion?

glass slipper

The VR1 synthetic 10W30 is so hard to find, it's not even on their website...could be because it doesn't exist. They do have synthetic racing oil but it's not for street use unless you plan on changing your oil every couple of weeks...it doesn't have the additives to prevent corrosion due to acid forming from combustion blow-by gases mixing with condensation which forms during engine cool down.

When it comes to the oil you use, you can trust Marc Haibeck all you want and he can preach all he wants, but at the end of the day he's just expressing an "opinion" tainted by the fact he sells Amsoil. There are plenty of ASTM/SAE tests to prove SM rated oil with .08% ZDDP is more than capable of providing the required anti-wear properties for older engines as well as older DOHC engines...irrefutable facts, not biased opinions.

My reference is back on post #22...I guess you neglected to read the whole thread. ZDDP wasn't just for anti-wear, it was also used as an anti-oxidant and getting close to .14% can have bad long term affects on your engine. At .20%, it attacks your engine causing spalling of the camshaft of which we have four. If the failure you noted above of an LT5 cam was the cam bearing, ZDDP would have no affect since journal bearings have hydrodynamic lubrication, not boundary layer lubrication which ZDDP is for.

My expertise is based on 28 years of working main propulsion for a small canoe club you may have heard of...the US Navy. We put 100,000 HP to the water through two shafts, reduction gears as big as a house, and controllable pitch propellers. It's my job to see that every single HP gets to the water and the ship can attain max speed as it sails into harms way...oil is a pretty important part of the equation. We have an oil lab on site we can run just about any test you want. We usually look at TBN, viscosity, % water contamination, particulate contamination from 5µ to >100µ, and we have a plasma mass spectrometer to facilitate spectrographic analysis of oil samples for wear metals in PPM. We have tests for salt water contamination looking at chlorides but I take a shortcut by doing a spectro and looking at sodium content...it always amazes me the number of people that don't realize sodium is classified as a metal on the Periodic Chart of Elements. We don't do any cold temperature tests so no Mini-Rotary Viscometer, engine room equipment doesn't usually start unless oil temperature is over 85°F but that's what sump heaters are for. With oil capacities of 1500-3500 gallons depending on the system...oil changes get expensive so we keep on top of things to get 10 years use out of the oil.

pantera1683

Here you go, http://www.amazon.com/Valvoline-6790.../dp/B002ZSM2B0

This is the racing formula, but it's not the "not street legal" formula.

Also, thanks for your service

Your conclusion about Haibeck doesn't hold water. Yes he sells Amsoil but Amsoil sells plenty of different types of oil, not just the high zinc formula. Also, there are other brands of oil that have high zinc content. A lot of engine builders and guys running pre-90s engines like the high zinc stuff for the same reasons Haibeck gives for the LT5.

In fact Mobil1 0w40 European formula is a high zinc oil and it is designed for extended drain intervals and meets the higher European manufacturers specs.

93RubyZ

This thread is almost a year old. Any new developments in oil products since then? I'm due for an oil change and will need to determine which oil to use -- am leaning towards Mobil 1 0W-30 at the moment.

Dynomite

I would lean this way



https://www.amsoil.com/a/synthetic-motor-oil-engine-oil

Or for Mobile 1

http://www.zddplus.com/

glass slipper

Actually, there has been a new development. Starting with the 2011 model year, all GM gasoline engines must use oil that meets the new dexos1™ specifications and yes this includes the Corvette which used the GM4718M spec from 1992 to 2010 (with updates along the way). The license for GM4718M oil will likely expire at the end of 2011 which means GM will no longer monitor that specification and any oil labeled as such will be a crap shoot as far as the buyer is concerned as they will have no way to know the company has actually made the oil to the old GM4718M spec. Yes, the GM4718M spec will soon be dead but dexos1™ is backward compatible to all engines made by GM.

http://www.mobiloil.com/USA-English/...l_1_5W-30.aspx
http://www.imakenews.com/lng/e_artic...13Kwd,b4bRbnH9
http://www.imakenews.com/lng/e_artic...7bMpH,b4bRbnH9 (This is an old link when GM was going to call it GEOS 1 but I've had the link for a while now.)
http://www.asashop.org/autoinc/nov2009/cover.htm
You'll see dexos1™ leapfrogged the new ILSAC GF-5 spec which was also introduced for the 2011 model year.
I'm sure there are a lot more links available but I haven't really looked into it for about a year, just do a search using "dexos1" and I'm sure you'll get plenty of hits.

The main advantage to dexos1™ is longer oil change intervals (15k miles and more) as we head towards 30k-40k mile oil change intervals...yes, 30,000-40,000 miles between oil changes. Expect the 3000 mile oil change guys reaction to be

I started doing 7500 mile oil change intervals in 1983 with 5W30 non-synthetic oil when everybody else was using 20W50 and 3000 miles. NASCAR was using 5W30 at the time and GM recommended 7500 mile intervals...I'm an early adopter of new technology and better methods.

But back to your choice of oil...Mobil 1 0W30 is a great pick. There are many others that will work just as good so expect others to chime in with their favorite or mimic what the latest guru said was the best. Oil technology has come a long way in the last 20 years and there are very few out there I'd consider "bad" for our engines. If you're racing, you'll need to consider the oil temps you run at to pick the best weight as higher oil temps will require heavier weight oils to maintain film strength.