Ladies and gentlemen,

to open just another oil thread. ;-)

Living in Singapore, where the ambient temps never really go below the mid seventies, I figured why not run a monograde engine oil instead of the multigrade. As per HD owners manual, a straight 50 should do just fine.

I came across a product of an Australian manufacturer Penrite: https://penriteoil.com.au/products/m...l-hd-50-sae-50

I know there are "better" oils to use, but is there any risk to using this oil with service intervals below 3000 miles? My 103 engine is equipped with Andrews 57H cams and Wood roller lifters, mapped with an FP3, but otherwise the engine is stock.

Thanks already, best, niv

 

many moons back, the fed's did a research on engine oils here in the states. there were many brands tested and it was found that cheaper oils lost their ability to change vis in short order so the recommendation was to use straight weights. now oil has progressed from run of the mill to engine specific. i prefer straight myself but hard to find OTC.

 

Is 20w50 difficult to find in Singapore?

There is no advantage to using single grade oil...

 

Are you having or finding an issue with the 20W-50 ? Have you considered the Synthetic ?

 

Valvoline makes VR1 in straight 50. Not sure about price/availability down under. But 20w50 makes more sense really.

 

HD 2017 (page 146) and other years Recommended oils. Above 60 degrees 16C SAE 50
Above 80 degrees or 27 C SAE 60

 

 

The service manual says to use the proper grade of oil for the lowest expected temperature expected before the next oil change.

It also recommends 20w50 at all temps above 39 degrees....

 

yes but at the temps quoted HD say those weight are just fine. Pretty much what they have said for years. I run 20/50 from well below zero to as hot as it gets never much of an issue. Once below 10 degrees without help HD won't start that is not an oil issue alone.
for the heck of it just looked in my 1996 owners manual different wording but say same thing as the 2017.

 

My `89 owners and service manuals also say the same...