Engine oil type and viscosity

[Oversize]

I did a search and couldn't find a topic on engine oils apart from pricing so I thought I'd start another.

Out shopping at Autobarn and it's as confusing as ever! I've moved from Shell oils to Penrite and I've found Semi-synthetic 15W-40 to be the most suitable for my applications in the M117, M100 and the Ford AU 5L V8 Windsor. I'd prefer something a little thicker like 15W-50, 20W-50, or 20W-60 but they just don't make it in Semi-synthetic.

They do make a 20W-50 which is a little cheaper being in their 'premium' mineral oil range, but doesn't appear to have extra zinc.

HPR 15 is a good viscosity at 15W-60 and has full zinc, but it's full synthetic and quite pricey.

Strangely HPR 30 is a full zinc mineral oil at 20W-60.

 

[BenzBoy]

HPR 30 could be used although it is made specifically for engines with larger tolerances.
Why not go full synthetic?
Regards,
Brian

 

[abl567]

Full synthetic is a disaster in an M100, it will find any way to leak out, or in to valve stems and past rings. Larger tolerances as you mentioned.
Also mineral oils seem to be more tolerant of the hydrocarbon deposits these old engines produce.

 

[BenzBoy]

Well HPR 30 is what Penrite recommend for the 6.9 so maybe that's what is needed? Not synthetic and Zinc included.
Regards,
Brian

 

[motec 6.9]

I have HPR 30 in my 6.9 .

 

[Oversize]

Personally I think any fully synth oil is too thin despite advertised viscosities. And it's also rather expensive considering the 6.9 takes 11L of the slippery stuff!

 

[Oversize]

I used to like Shell oils when the added tint to their engine oils... Semi synth was a nice green and fully synth was a purple! It looked better than the current yellow which looks old straight out of the container! I guess you can thank the muppets that mistook it for coolant or ATF for the changes...