Was wondering about this today. Growing up I recall diesel rated straight 30 weights and 15w40
When did 10w30 HDEO’s come around?
- Thread starter 53' Stude
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I believe that 10w30 predated 15w40, which was a wildcat grade achieved by mixing SAE 50 with 10w30.
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I remember when Pennzoil put out some really odd viscosity oil. I believe they even made a 15W-20 flavor.
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I can’t find any answer to when 15w40 oil came out. Google is worthless
Thanks for your info user friendly
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interesting question @53' Stude
IMO, I think it is MPG related for the most part. I stick with the good ole 15w40 but have considered 10w40 for easier winter starting... My UOA's showed 5w40 was prone to shearing in my truck.
Just my $0.02
IMO, I think it is MPG related for the most part. I stick with the good ole 15w40 but have considered 10w40 for easier winter starting... My UOA's showed 5w40 was prone to shearing in my truck.
Just my $0.02
I recall my real dad telling me when he ran a R Model day cab MACK circa 1981 they plugged the rigs in but they sat outside all time. Never a issue with 15w40 on starting.
Very good info
When was the SAE J300 viscosity table established?
When were SAE 15, 15W, 25 & 25W grades added?
I'll guess that 15W40 was accepted by the SAE around 1973, 50 years ago today.
Very Interesting! Point #2 is why I saw 10w-30's having more additive package "Totals" than a 15w-40 when I put together "Diesel VOA Database".
I know the 1994.5 7.3 Powerstroke called for 15w-40 but I believe the prior International engines were 10w-30 or a straight 30. So possibly when you started seeing auto's move away from straight grades, obviously, in diesel engines. 1980's?
I can’t find any answer to when 15w40 oil came out. Google is worthless
Thanks for your info user friendly
Amoco Super 300 originally was API CD spec. Which came out in 1955. And wasn’t replaced till 1983 as standard.
If I remember correctly from the stories, the first 15w40’s appeared in the mid 70’s. 74-77 iirc. We have some old memorabilia from when they launched the Amoco 300 15w40.
I’ll ask my dad tomorrow. He’ll know the answer.
Also probably not of value to the OP: I know that up until about 1996* , most off the shelf multi-viscosity oils were dual rated for both gasoline (S) and diesel (C). I used to buy regular 10W30 oil of any brand for my small workplace Kubota tractor because it had the "C" rating. In 1997 I became alarmed when my new case of NAPA 10W30 had printed on it "For gasoline engines only". Whaaaaat???? I was not educated about HDEO oils at the time, but remember switching to 15w40 because I could not find 10W30 "C" rated oils anymore - note that I was not BITOG OCD at that time, and just followed the tractor dealer's advice to use 15w40 HDEO "C" rated.
* 1996 +/- is when the feds changed engine oil classifications for gas/diesel. This started my interest in lubrication for fear of ruining my diesel tractor engines. I remember calling NAPA/Valvolene to get the answer about "C" being dropped off regular oils.
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I was told back in the day that "C" was for compression ignition and "S" for spark ignition.
The HDs were called "Caterpillar series III" and were available in 10w30 and 20w40.
Mono/single grade "CD II" were typically lower ash formulas and recommended for GM 2 stroke Detroit Diesels.
I don't remember using 15w40 in the 1970s. For motorcycles I used HD 30, 40 or 50, or motorcycle specific 10w40 & 20w50.
Small gasoline engines on the railway used SAE 30 HD. I remember using Mobil 5w20 in LPG fueled RR switch heaters in 1975.
Most North American built cars and pickup trucks have recommended 5w30 since the mid 1960s.
HDEO 5w30s haven't been commonplace until recently. Most of them have both C&S approvals.
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I have the original engine manual for a Perkins 4.236 diesel installed in my boat in 1978 and it has a full page of oil specs for different brands. There is no mention of 15W-40 as a grade. The closest is 20W-40. There are lots of listings for various brands at 10W-30. I currently run Rotella 15W-40, but it is interesting to see that back in the day the recommendation for the Rotella of 1978 was for 20W-20 or 20W-40. When I bought the boat the PO had been using straight 30 weight, which my engine manual lists as the go-to when temperatures are above 80F. One thing I never understand with boat engines is why the air temperature should matter much. Water temperature would seem to be the most pertinent number, and that never gets above 90F except maybe in the Persian Gulf. Frankly, I have never seen my water temperature gauge run hot or cold unless something was plugging the cooling system or the thermostat was sticking. No matter how hot or cold (I have run it below freezing) the engine gets up to temp. and just stays there.
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The inception of the SAE table traces its roots back to 1922, where an intriguing grade of 15 made its initial appearance, as you rightly noted. However, this grade of 15 was eventually supplanted by a grade of 10 prior to 1926. It is noteworthy that the advent of winter grades was deferred until 1932, coinciding with the inclusion of 10W and 20W within the SAE table.
In due course, the grade of 10 was phased out, leaving the entry-level low-viscosity grade of 20 as the first grade of the normal (non-winter) grade. Subsequently, in 1949, the SAE table witnessed the introduction of the winter grade 5W. Subsequent amendments occurred in 1975 with the introduction of the 15W grade, followed by the incorporation of both the 0W and 25W grades in 1979.
1922 - 15
1926 -
1932 - 10W & 20W
1949 - 5W
1975 - 15W
1979 - 0W & 25W
The emergence of HDEO oil with a viscosity grade of 0W-30 in the early 1980s holds profound significance within this context. Of particular note is its origin from the esteemed Gulf company, which, alongside Mobiloil, made substantial contributions to the advancement of PAO development in the real commercial oils. It is important to acknowledge that the present-day recognition of PAO as a legitimate oil owes much to the combined efforts of Gulf, Ethyl, and Mobiloil (excluding the German SS 900-1000 series oils during the Second World War era).
Gulf oil, in particular, warrants special attention for its pioneering role in introducing the 0W-30 viscosity grade and its deliberate positioning as HDEO in targeted marketing campaigns. By catering to the needs of heavy trucks, it marked a significant milestone in the evolutionary trajectory of synthetic oils. This momentous development commenced around 1981.
The first 5w40 I saw around 1974 was Gulf. (I'm a Boomer, raised on the prairies by war vets and depression survivors)
In western Canada, Gulf took over BA gas stations in the late 1960s/early 70s.
Petro-Canada took over Gulf gas/service stations in the 1990s, followed by a feeding frenzy on Gulf Canada's assets.
See WIKI for the story.
SAE 15W was added to J300 in 1975 as per the above post. 15w40s would have been rolled out in late 75 early 76.
In western Canada, Gulf took over BA gas stations in the late 1960s/early 70s.
Petro-Canada took over Gulf gas/service stations in the 1990s, followed by a feeding frenzy on Gulf Canada's assets.
See WIKI for the story.
SAE 15W was added to J300 in 1975 as per the above post. 15w40s would have been rolled out in late 75 early 76.
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Here is a 2000 Ford Super Duty owners manual page asking for 10w30 HDEO.
