ZF6 lube (NEW inquiry)
Thread Starter
Racer
Joined: Jun 2010
Posts: 402
Likes: 1
From: Tabernacle NJ
ZF6 lube (NEW inquiry)
I know this has been beyond beaten to death and 90% of people seem to say Castrol TWS 10w60 or the new(ish) GM recommendation.
My question is whether or not Castrol Edge 10w60 is also acceptable. According to Castrol (and BMW) its approved for use in the same BMW models that the TWS oil is.
This is the oil in question. Note how it explicitly states BMW's acceptance.
http://www.castrol.com/castrol/produ...tentId=7027067
This is NOT in question, The Castrol Edge Sport 10w60, as apparently its different and does NOT meet BMW specs.
http://www.castrol.com/castrol/produ...tentId=7027056
I just wanted to know if anyone knows for sure if this will work. It meets the same specs as TWS, but there may be something that made it work well in the ZF6 that BMW doesn't care so much about? If its good to use it would certainly be cheaper and easier to get a hold of..
My question is whether or not Castrol Edge 10w60 is also acceptable. According to Castrol (and BMW) its approved for use in the same BMW models that the TWS oil is.
This is the oil in question. Note how it explicitly states BMW's acceptance.
http://www.castrol.com/castrol/produ...tentId=7027067
This is NOT in question, The Castrol Edge Sport 10w60, as apparently its different and does NOT meet BMW specs.
http://www.castrol.com/castrol/produ...tentId=7027056
I just wanted to know if anyone knows for sure if this will work. It meets the same specs as TWS, but there may be something that made it work well in the ZF6 that BMW doesn't care so much about? If its good to use it would certainly be cheaper and easier to get a hold of..
Race Director
Joined: Nov 2003
Posts: 12,220
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
I just wanted to know if anyone knows for sure if this will work. It meets the same specs as TWS, but there may be something that made it work well in the ZF6 that BMW doesn't care so much about? If its good to use it would certainly be cheaper and easier to get a hold of..
The oil you linked above does not claim compatibility with a GL-4 requirement. So, I wouldn't use it. I'd use a GL-3 lube before that.
As compared to a motor, the ZF also needs oil with high sheer resistance, but it also needs the correct friction modifiers for bronze synchros. (Plus, I'm not sure you'd want detergents.)
Race Director
Joined: Sep 2001
Posts: 14,648
Likes: 750
From: NEwhere Ohio
im tired of replying about this.
dont use the castrol bmw crap. That stuff belongs in bmw's - not corvettes. I dont care what zdocs goofy experiments show. The castrol stuff I had did not say 'EDGE' on it or anything like that. It was stuff that I bought, in '03, at a BMW dealership. It said 10w-60 on it. It was a full synthetic.
Made my car shift terrible. To be more specific, I had to abort full throttle dragstrip runs because the lever would not physically move from 2nd to 3rd gear under high RPM, quick shifts.. Also, grinds on the 1-2 shift were a common result.
following zfdoc's advice, I first replaced the clutch hydraulics (master, slave, and line), properly bled it and no luck. Still grinds, and lever wouldnt move into gear.
I was on the verge of paying $2000 for a new gearbox or paying even more to have the synchros on mine rebuilt. I swapped the oil back to whatever the updated pn gm now recommmends (because the original stuff is no longer available) and all my problems went away 100%.
dont use the castrol bmw crap. That stuff belongs in bmw's - not corvettes. I dont care what zdocs goofy experiments show. The castrol stuff I had did not say 'EDGE' on it or anything like that. It was stuff that I bought, in '03, at a BMW dealership. It said 10w-60 on it. It was a full synthetic.
Made my car shift terrible. To be more specific, I had to abort full throttle dragstrip runs because the lever would not physically move from 2nd to 3rd gear under high RPM, quick shifts.. Also, grinds on the 1-2 shift were a common result.
following zfdoc's advice, I first replaced the clutch hydraulics (master, slave, and line), properly bled it and no luck. Still grinds, and lever wouldnt move into gear.
I was on the verge of paying $2000 for a new gearbox or paying even more to have the synchros on mine rebuilt. I swapped the oil back to whatever the updated pn gm now recommmends (because the original stuff is no longer available) and all my problems went away 100%.
Thread Starter
Racer
Joined: Jun 2010
Posts: 402
Likes: 1
From: Tabernacle NJ
Why does what BMW "cares about" matter? ZF was the one who determined which oils qualified for the GL-4 rating our transmissions "require". Because ZF sold the rights to the ZF-6 years ago, there will never be testing/updates to the two oils already specified.
The oil you linked above does not claim compatibility with a GL-4 requirement. So, I wouldn't use it. I'd use a GL-3 lube before that.
As compared to a motor, the ZF also needs oil with high sheer resistance, but it also needs the correct friction modifiers for bronze synchros. (Plus, I'm not sure you'd want detergents.)
The oil you linked above does not claim compatibility with a GL-4 requirement. So, I wouldn't use it. I'd use a GL-3 lube before that.
As compared to a motor, the ZF also needs oil with high sheer resistance, but it also needs the correct friction modifiers for bronze synchros. (Plus, I'm not sure you'd want detergents.)
Your entire post has NOTHING to do with what I asked. Thanks for trying. If you're so tired of replying about it, I have a solution. Don't.
Race Director
Joined: Oct 2005
Posts: 11,765
Likes: 175
From: Rolla Missouri
2021 C4 of the Year - Unmodified Finalist
St. Jude Donor '10 thru '25
Ok, I'll chime in then. They were BOTH just trying to help!
The ZF-6 transmission is no longer produced. And nobody is going to be doing any oil testing to certify if any new oil does/does not meet any specs for it.
I sure wouldn't use what you linked in my ZF-6.
But since you insist it is so good and meets all the BMW specs go ahead and use it.
You will never find any documentation that will prove/disprove it.
PS: I've been using Amsoil in mine.
http://www.amsoil.com/storefront/mtf.aspx
The ZF-6 transmission is no longer produced. And nobody is going to be doing any oil testing to certify if any new oil does/does not meet any specs for it.
I sure wouldn't use what you linked in my ZF-6.
But since you insist it is so good and meets all the BMW specs go ahead and use it.
You will never find any documentation that will prove/disprove it.
PS: I've been using Amsoil in mine.
http://www.amsoil.com/storefront/mtf.aspx
Le Mans Master
Joined: Oct 2007
Posts: 9,680
Likes: 3,427
From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
2024 C5 of the Year Winner - Modified
2023 C5 of the Year Finalist - Modified
2022 C5 of the Year Finalist - Modified
St. Jude Donor '09-'10-'11
Ok, I'll chime in then. They were BOTH just trying to help!
The ZF-6 transmission is no longer produced. And nobody is going to be doing any oil testing to certify if any new oil does/does not meet any specs for it.
I sure wouldn't use what you linked in my ZF-6.
But since you insist it is so good and meets all the BMW specs go ahead and use it.
You will never find any documentation that will prove/disprove it.
PS: I've been using Amsoil in mine.
http://www.amsoil.com/storefront/mtf.aspx
The ZF-6 transmission is no longer produced. And nobody is going to be doing any oil testing to certify if any new oil does/does not meet any specs for it.
I sure wouldn't use what you linked in my ZF-6.
But since you insist it is so good and meets all the BMW specs go ahead and use it.
You will never find any documentation that will prove/disprove it.
PS: I've been using Amsoil in mine.
http://www.amsoil.com/storefront/mtf.aspx
Another vote for Amsoil! I roadrace my car with Amsoil and it always shifts smooth. 
Thread Starter
Racer
Joined: Jun 2010
Posts: 402
Likes: 1
From: Tabernacle NJ
I understand they're trying to help, and I appreciate that but they just failed to provide information on the matter at hand.
I was just wondering if anyone had any experience with it. I'm not the one saying that the Castrol Edge is great, but some people in the BMW crowd are claiming its the exact same thing as the TWS. Just a different bottle and price tag. I don't know if there's any truth behind this, and it doesn't seem like anyone does.
Maybe I should try to shoot Castrol and email and see if they say the formulations are identical, but I doubt they'll be helpful. But if TWS 10w60=Edge 10w60 (in a different bottle), then (transitive property) a ZF6 that is happy with TWS will be happy with Edge. And many people say their ZF6's are indeed happy with TWS, despite the small group that says theirs was not.
I was just wondering if anyone had any experience with it. I'm not the one saying that the Castrol Edge is great, but some people in the BMW crowd are claiming its the exact same thing as the TWS. Just a different bottle and price tag. I don't know if there's any truth behind this, and it doesn't seem like anyone does.
Maybe I should try to shoot Castrol and email and see if they say the formulations are identical, but I doubt they'll be helpful. But if TWS 10w60=Edge 10w60 (in a different bottle), then (transitive property) a ZF6 that is happy with TWS will be happy with Edge. And many people say their ZF6's are indeed happy with TWS, despite the small group that says theirs was not.
Thread Starter
Racer
Joined: Jun 2010
Posts: 402
Likes: 1
From: Tabernacle NJ
My only gripe with amsoil is that they certainly don't make it one of the easier products to get a hold of... I always prefer to buy things locally over ordering, paying shipping, and waiting and amsoil isn't sold in retail establishments.(that I know of)
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
Thread Starter
Racer
Joined: Jun 2010
Posts: 402
Likes: 1
From: Tabernacle NJ
Still not an answer to the original question, which was NOT which oil to use, but only if the TWS and Edge are the same. A question about Castrol should not be answered with Amsoil...
Advanced
Joined: Jan 2002
Posts: 87
Likes: 0
From: Auburn WA
Well, according to various BMW Forums, they are the same. Reference the following thread:
http://www.m3forum.net/m3forum/showthread.php?t=236372
So the bottom line is this. If you and ZFDoc think that Castrol TWS is acceptable for your ZF-6, then the Castrol EDGE should do just as well. Personally, since no one is going to replace or warranty my transmission if it doesn't work, then I will continue to use the GM-recommended oil. YMMV
http://www.m3forum.net/m3forum/showthread.php?t=236372
So the bottom line is this. If you and ZFDoc think that Castrol TWS is acceptable for your ZF-6, then the Castrol EDGE should do just as well. Personally, since no one is going to replace or warranty my transmission if it doesn't work, then I will continue to use the GM-recommended oil. YMMV
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
You're not going to get an answer to your specific question. The data doesn't exist.
If you want an answer, buy the oil, put it in. If it shifts "fine" (what ever is acceptable to you), run it for a period, take a sample and send it to be analyzed. The oil analysis results will be the answer to your question. Only way to know. Anything else is just guessing.
If you want an answer, buy the oil, put it in. If it shifts "fine" (what ever is acceptable to you), run it for a period, take a sample and send it to be analyzed. The oil analysis results will be the answer to your question. Only way to know. Anything else is just guessing.
Race Director
Joined: Nov 2003
Posts: 12,220
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
Do you seriously think someone here has done the analysis to see if they're the same -- especially for ZF use?
Your idea about contacting Castrol makes more sense. It would be surprising if they'd openly admit a cheaper product is identical to a more expensive one. OTOH, if the TWS is a "stealership" brand, it wouldn't surprise me.
FWIW: Redline also packages their MTL as motorcycle chain lube! (Same stuff, different bottle, called V-Twin Primary Case oil). I learned that by talking to the manufacturer vs a forum.
Thread Starter
Racer
Joined: Jun 2010
Posts: 402
Likes: 1
From: Tabernacle NJ
Gregg, I just thought that maybe someone else had heard or confirmed through castrol or some other source. Like your example, manufacturers do tend to do a fair bit of re-branding of identical product.
Race Director
Joined: Nov 2003
Posts: 12,220
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
He said he might even deliver it since we live so close!
BTW,,,I asked him what the GL rating was. He called their tech office and the reply was GL-4. That happens to be what our ZFs "want". I don't think very many of the MTL options (Penzoil, Redline, etc...) have that correct rating. He also confirmed it's fully synthetic.
It's $11/qt. The GM replacement is $15 (making it higher). The TWS stuff is the highest. But I, like several others, don't like the way it performed (because of it's heavier weight). The ZF has lots of small bearings that are better lubricated by a lighter-weight oil (IMO). FWIW: The ZF-5 used in 3/4 Ton Ford Trucks used a synthetic ATF!!! That, by itself, tells me alot.
Race Director
Joined: Nov 2003
Posts: 12,220
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
I've always been surprised ZFDoc would post (and apparently promote) a lube with such a high-percentage particle wear. That's the case for the TWS stuff. It would have been nice if he'd compared it to the GM stuff (when it was still around).
Because of it's viscosity, the TWS stuff is probably the best for racing/high-heat use. And, that might be where high-wear would occur for ANY lube. IOW, 10% wear in 12k miles might not be "bad" if you're running the crap out of it! But I have to assume the OEM, lower-visosity stuff has better all-around properties for GM to have originally selected it.
Race Director
Joined: Sep 2001
Posts: 14,648
Likes: 750
From: NEwhere Ohio
Why care? Because BMW came up with the standard for TWS, which ZFDoc seems to like. Maybe BMW's standard for their high power/liter and high revving motors includes an oil with a higher shear resistance. As for meeting the GL-4 requirement: its not sold as a gear oil. And neither is TWS, which is recommended. So neither of them are judged by that criterion.
Your entire post has NOTHING to do with what I asked. Thanks for trying. If you're so tired of replying about it, I have a solution. Don't.
Your entire post has NOTHING to do with what I asked. Thanks for trying. If you're so tired of replying about it, I have a solution. Don't.
However, buried in my post is a sentence mentioning that the terrible castrol crap I put in my car did not have 'EDGE' or whatever written on it.
Last edited by dizwiz24; Aug 2, 2010 at 08:28 PM.
Team Owner
Joined: Aug 2005
Posts: 34,988
Likes: 515
From: Riverside County Southern California
Co-winner 2020 C4 of the Year - Modified
2018 Corvette of Year Finalist
2017 C4 of Year
2016 C7 of Year Finalist
St. Jude Donor '09 thru '20
My LT4 Vette is the first ZF6 I've own and always had Castrol TWS. I dont know if this is the best oil for it but, I should try the Amsoil or Royal Purple Synchromesh Transmission Oil.
I still remember the BMW sales person's face when I told him that I was buying TWS oil for a Corvette transmission.
I still remember the BMW sales person's face when I told him that I was buying TWS oil for a Corvette transmission.
