Use of SAE 40 motor oil

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Can anyone advise on the use of SAE40 motor oil ? Is it only for older vehicles and will it help with vehicles that tend to use oil between services ? Please note i am based in South Africa where it rarely gets to 0 deg C ,with the average temp being between 27 and 30 deg C
 
The oil is for use in my workshop on clients cars .Mainly repair vehicles from the eighties to late nineties .I have signed off a order for different grades ,40 ,20w50 and 15w40 .I am getting the 40 at a good price ,R110 for 5lt and my reasoning is that due to the poor economy i am seeing more 'clunkers' in for running repairs whereby cost is everything .
 
Originally Posted By: Matt97
The oil is for use in my workshop on clients cars .Mainly repair vehicles from the eighties to late nineties .I have signed off a order for different grades ,40 ,20w50 and 15w40 .I am getting the 40 at a good price ,R110 for 5lt and my reasoning is that due to the poor economy i am seeing more 'clunkers' in for running repairs whereby cost is everything .


If that is the case I think it would be just fine.
 
I would not use a 40W oil if it was not called for in the owners manual. Usually they have a temp and viscosity chart. But if the vehicles are old, probably no owners manual.

Most cars take 30W or below. Its trucks and marine engines that take 15W40 or 5W40.
 
Are you guys looking at his post at all? His temperature averages between 27 and 30° C. That's 81-86°F. I'd say his choice of a 40 weight would be perfectly fine, even though it might be considered a bit thick for short tripping.
 
Originally Posted By: Matt97
The oil is for use in my workshop on clients cars .Mainly repair vehicles from the eighties to late nineties .I have signed off a order for different grades ,40 ,20w50 and 15w40 .I am getting the 40 at a good price ,R110 for 5lt and my reasoning is that due to the poor economy i am seeing more 'clunkers' in for running repairs whereby cost is everything .


For ambients of 27 to 30*C , monograde 40 is fine in terms of viscosity grade.

However, there is a catch here ...... namely its API ratings??
In Malaysia, the SAE 40 monograde PCMO is typically of API SF rating .....
which according to API, is meant for 1988 or older vehicles and does not meeting your requirements.
Monograde SAE 40 SL is your minimum requirements ..... and it's availability is ....... ??

http://www.oilspecifications.org/api_eolcs.php
 
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The 40 oil is only as a shop oil , more modern and diesels will use the grade as specified in the service book .
 
Originally Posted By: userfriendly
This is the 5th summer for SAE40 in my Duramax.
Straight 40? If so it is a BITOG no!no!
 
Originally Posted By: CT8
Originally Posted By: userfriendly
This is the 5th summer for SAE40 in my Duramax.
Straight 40? If so it is a BITOG no!no!
If it is hot enough, it shouldn't hurt anything, not sure I would do it below freezing-UNLESS I had an oil pan heater plugged in & hot first.
 
Firstly, monograde oils were around before W rated multigrade oils. If you look at an old shop manual lets say 1964 Chevrolet Corvair it will say to use SAE30 oil or 10W-30 , as that was acceptable for all season weather conditions. (in north america). Later on multi grade oil became the standard.

Many other types of equipment use SAE40 oil. 2 stroke Detroit Diesel engines, Locomotive/ferry boat engines typically use 20W-40 or SAE40, referring to GE or EMD engines. Industrial natural gas/landfill gas/digester engines use low ash SAE40 oil. Ship engine oil for slow speed Wartsilla engines SAE40 TBN of 50.

Basically any engine that doesn't have to cold start or has long run time typically uses SAE40 for the best oil control. SAE40 utilize more actual oil (i'm talking about refined crude.. dino) and no VI improvers, less additives, less grade sheering. Thats how they get the representation for being heavy duty.

However this analysis had an interesting comparison and conclusion between 15W-40 and SAE40.
'Solutions to the Engine Failures That Occurred Soon After
Galveston Ferry Operations Began Using Texas Low Emissions
Diesel Fuel' - see link below
https://www.utexas.edu/research/ctr/pdf_reports/0_5532_1.pdf
 
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