Motor oil survey.
Melting Slicks
Joined: Jun 2011
Posts: 3,116
Likes: 598
Why did you choose 20/50 vs 10/30
The z-rod is near the top for oils for wear protection for the older corvette's/
Safety Car
Joined: Sep 2011
Posts: 4,120
Likes: 1,230
From: Madeira Beach, FL
2024 C8 of the Year Finalist - Unmodified
2024 C2 of the Year Finalist - Unmodified
2023 C2 of the Year Finalist - Unmodified
2020 C3 of the Year Finalist - Unmodified
Castrol High Mileage 20/50.
Switched from Brad Penn 10/30.
Hot summer time cruising 20/50 protects better.
Come October she's hibernating like a bear.
Marshal
Switched from Brad Penn 10/30.
Hot summer time cruising 20/50 protects better.
Come October she's hibernating like a bear.
Marshal
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
CF Community Team
Joined: Oct 2004
Posts: 19,371
Likes: 5,250
From: Cape Cod, Mass.
2025 C6 of the Year Finalist - Unmodified
2025 C8 Z06/7/E-Ray of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2021 C8 of the Year Finalist Unmodified
2020 Corvette of the Year Finalist (performance mods)
2019 C1 of Year Winner (performance mods)
2017 Corvette of the Year Finalist
2016 C2 of Year
2015 C3 of Year Finalist
Shell Rotella 15W 40 and a Wix oil filter 
Melting Slicks
Joined: Jun 2011
Posts: 3,116
Likes: 598
Melting Slicks
Joined: Jun 2011
Posts: 3,116
Likes: 598
Even my original L48 with 180k km ran smoother quieter with 10-30 Zrod than any other x/50 weight oils.
But I never did have any oil pressure issues.
I did try Mobil 1 15/50 when ZDDP oils were harder to find. Then I found the ZROD line with amsoil. went back to 10-30 for better startup protection. Flows much better for my colder climate area.
Thread Starter
Racer
Joined: Aug 2014
Posts: 448
Likes: 42
I was talking to the Amzoil rep, and he recommended the 20/50 Z rod for my BB. So I tried it. Seems very quiet on start up and general running. I am using the Valvoline Vr-1 20/50 in my Harley, seems to work well so far. Is this VR-1 the one you would use in the Vette?
And what is this Brad Penn oil? Never heard of it before. ?
And what is this Brad Penn oil? Never heard of it before. ?
Melting Slicks
Joined: Oct 2011
Posts: 3,453
Likes: 67
From: Midland Ontario
NCM Sinkhole Donor
Yep, that's it. I can only get that grade at my local NAPA, they can't get the 10W30........so to get the ZDDP, that's what I've got to work with. The 20W50 viscosity falls inside our summer temperature range in my owner's manual, car seems fine, motor's never been apart in 36 years.
Melting Slicks
Joined: Oct 2011
Posts: 3,453
Likes: 67
From: Midland Ontario
NCM Sinkhole Donor
Interesting, my small town SuperCentre has a moderately sized auto section; but I've never seen it there. Will have to check next time I'm there. I wonder why they won't transport the 10W30 across the border?
