New Castrol oil for the classics! "Castrol GTX Classic" 20W-50

Messages
1,739
Location
California
What ?
I always used high zinc oils in my shared sump motorcycles, never a problem. Clutch worked well even after a decade.

It's friction modifiers I was always told to avoid in motorcycle oil.
Agreed.
My SV650s loved Rotella T4 15w40
I'm super excited to try this in my air-cooled Honda motorcycle. It's a blast to shift it at high rpms. The higher anti-wear additives in this oil are definitely needed in my application.
My mistake. I was confusing extreme wear protection with friction modifiers. Sorry.
 
Messages
3
Location
AZ
So I emailed Castrol to ask about the zinc content and this is the response I got. I'm hoping it will help others make a decision but I'll definitely be trying this in my Harley since I've been running Castrol GTX 20w50 in it for almost 60k now.

Email from Castrol


"Thank you for contacting Castrol North America.

Castrol GTX Classic 20W-50 is specially formulated to provide unsurpassed wear protection for classic and collector cars as well as racing applications.

Castrol GTX Classic 20W-50 is a high-performance conventional oil formula for push-rod, flat tappet engines and performance cam applications. It’s blended with a high zinc (1400 ppm) and phosphorus content to help prevent premature aging, wear and metal fatigue on engines with high tension valve springs or performance modifications that create high contact pressure and extreme internal temperatures. Specially formulated engine oil for classic/collector cars, muscle cars, hot rods and race cars.

Castrol GTX Classic 20W-50 is suitable for use in automotive gasoline engines where the manufacturer recommends an API SJ or earlier specification 20W-50 lubricant.

NOTE: NOT FOR USE IN MODERN ENGINES WITH CATALYTIC CONVERTERS OR WET CLUTCH APPLICATIONS.

Castrol GTX Classic 20W-50 is available for purchase exclusively through Wal-Mart currently.

Castrol Consumer Relations"

Hope this helps, sounds like it could be a great oil to use. The only problem I see is them not making it for very long but I guess we will see what happens.
 
Messages
263
Location
USA
Interesting.

I'm sitting on about 30-40 of new unopened quarts of 20w50, 10w30, and 10w40 that I keep around just in case I end up with a classic car I need to start maintaining. :) Moving sales are fantastic place to buy up folks unwanted petrol products before their cross country moves... 25 cents per quart is the going rate.
 
Messages
1,405
Location
WV
Interesting.

I'm sitting on about 30-40 of new unopened quarts of 20w50, 10w30, and 10w40 that I keep around just in case I end up with a classic car I need to start maintaining. :) Moving sales are fantastic place to buy up folks unwanted petrol products before their cross country moves... 25 cents per quart is the going rate.
Any of you guys moving??😁
 
Messages
7,111
Location
Los Gatos, CA
Just bought out the last 4 quarts the local Wally World had.
My beloved Oldsey is gonna get a service next time I bring it over...
It has older Shell Rotella T 15w40 Dino in it now...
 
Messages
929
Location
New Hampshire USA
Couple weeks ago I posted buying 9 qts of the aforementioned oil to replace the Castrol muscle car oil that's in the 454 in my sig. Returned this oil as it`s not syn. Will probably use some T6 from the stash.
 
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