See my post in the 'This & That' forum section:



6 VOLTS/POS. GRD. NW INDIANA

Discussions about engine oil is a suitable topic for the Technical section.

Lorena, Texas (South of Waco)

I have sent several members 25 pages of oil test datta .conducted in the us(sparks nevada)with requests to share on this sit as so much miss info on oil.  this tests show positive info not to use diesel lub oil in gas engines.
 another fallacy is that diesel engines have unbernt fuel in the lube system .turbo charged as well as older super charged diesel engines use excesive air to cool the top end and when functioning as designed ther is no fuel delution. confirmed  by oil enalises. my experience comes from working for a cat dealer for 35 years in mainly engine and transmission devisions.
gas engines work on rich mixture to control combustion. seems to me it is a wast of time contributing to this sight,tho i have learned some info on casting numbers and other y block short cuts,mostly a lot of old based based along gossip

" This reduction in zinc ultimately ends up being a job justifying event that allowed a few individuals in the bureaucracy to keep their jobs.

The same thing happened with R-12 in the early 90s as a result of a confluence of events: DuPont's patents on the Freon family of refrigerants was running out for the last time (couldn't be renewed), and the EPA and NASA were looking to save themselves from budget cuts. So based on at best dodgy data we got R-134a, an inferior refrigerant compared to R-12, which DuPont had conveniently waiting in the wings, and the EPA and NASA had a reason for continued existence. Never mind that all this cost the refrigeration and HVAC industries, and average citizens, billions. Got to save those bureaucrats.

I tend to get misquoted on my stands on the various oils so here’s a refresher on the diesel ‘only’ oil statement.  I’m against it in gasoline engines due to its high detergent content and not the older levels of zinc/phosphorus content.  If the oil is rated for both gasoline and diesel engines, then go for it.  I simply don’t recommend using diesel only oil in a gasoline engine.  That high level of detergent makes for additional wear on both the flanks of the camshaft and the engine connecting rod bearings which comes to the forefront when used in a gasoline engine.  This is wear that does not show up specifically at the 30K mile mark but is clearly evident at the 100K mark when compared to gasoline engines running quality gasoline engine oil.  There is a given amount of diesel fuel getting past the rings on a diesel engine and that calls for a diesel engine specific oil; hence the high detergent amounts.  The latest diesel oils have reduced the ZDDP content so that’s not even a valid reason to use those diesel oils in a gasoline engine if doing it for its ZDDP content.  Most of this is subjective but is based upon 45 years of observations in tearing down engines that have used both of these oils.
 
Much of the problem with the zinc content in the oil was started with someone in the Government wanting the phosphorus content reduced.  For zinc to do its job in being an anti-wear agent, the phosphorus is the component that’s attracted to high heat friction areas and the zinc then simply follows along and transplants itself on those high heat spots.  Supposedly there was going to be an issue with catalytic converters going bad due to an excess of phosphorus getting past the rings.  This is a case where the prudent research was not done before hand which would have shown that oil consumption on gasoline engines is so minimal now that phosphorus at the catalytic converters was not going to be a problem.  This reduction in zinc ultimately ends up being a job justifying event that allowed a few individuals in the bureaucracy to keep their jobs.  The reduction and in some cases, the complete removal of ZDDP in the oil has fostered a new industry that is supplying engine oils outside of the API specifications that provides the older ZDDP amounts.  That’s my two cents on that issue.
 
So with that being said, even oils with a lower zinc/phosphorus (ZDDP) content are still fine in the older engines as long as the oil is changed out at more frequent intervals to compensate for the reduced ZDDP being used up sooner.  New or rebuilt engines with and without flat tappet camshafts do get the benefit of additional zinc supplements as there is considerably more wear taking place in those engines versus those that are fully broken in.

Lorena, Texas (South of Waco)

GL4 would be the go. I use the Penrite one in my early "39" toploader. You U.S. guys are lucky you will have choices, here its Penrite or nothing else as its all GL5 + now.



"Came too close to dying to stop living now!"

I normally use a GL4 after seeing many post about the additives in GL5. When I put the T85 in my Ranchero I used a Royal Purple lube that claimed it's safe for the soft metals, it's pricey but how often do you change it, I'll probably never change it again in my life time LOL.. It's been in there 3 years and no problems. 

I found GL-1 at my Tractor Supply and the brand is
Traveller
All mineral SAE 90
Ford Tractor
Transmission Fluid  and it has API Service GL-1 on it as well.

I run it in my T85 overdrive transmissions and my 1972 ford granny 4-speed and their doing just fine.


-Gary Burnette-

I asked a similar question a while back when I filled up my newly rebuilt Ford Toploader 4 speed. GL4 was the recommendation. Don't recall GL1 coming up. I finally found a 2 gallon jug on Ebay or Amazon for what I thought was a fair price. Everything I could find locally was GL4/5. Not what you want. I went with GL4. That would be my recommendation. My local good friend/retired mechanic concurred that GL5 can cause problems. You may be able to find the old thread if you look for it.  

I heard the same thing. I decided to stick to GL-1 rated oil just to be safe. NAPA has the GL-1 in there private label brand. Wasn't overly expensive either.

Durham Missouri