Synthetic Oils

Anecdotally, in my three old flat tappet engines I've been using Shell Rotella 15W40 diesel oil with high zinc content for many years Posted by johnlayzell 11/07/2014 19:15:06

I made reference in an earlier post to Penrite oils and to that end many of the posts talk about the suitability of various products and the need to have an oil that has a high zinc content. In my TA21 I use Shelsley Light which is readily available here in Australia. It also has the added benefit of what they call a &quot;tacky additive&quot;. This is important to me as the car is not frequently used, perhaps 2-3 times per month. Engine wear on startup should also be part of the debate. The web address below provides some insight into the product.   Lastly, I have no pecuniary interest in the company.  <!-- m --><a class="postlink" href="http://www.penriteoil.com.au/products/products.php?id_categ=14&amp;id_subcateg=69&amp;id_products=72">http://www.penriteoil.com.au/products/p ... roducts=72</a><!-- m -->  Richard  - Melbourne Posted by RichardWallach 14/07/2014 23:26:18

If you truly want to become immersed in the Dino vs Synthetic and many more oil discussions, visit and join this site:  <!-- m --><a class="postlink" href="http://www.bobistheoilguy.com">http://www.bobistheoilguy.com</a><!-- m -->  If you join, search for the posts of Caterham who appears to be somewhat of a guru.  Richard Wallach mentions engine wear on start up. Many modern manufacturers are now recommending 0W20 synthetic oils.  The act like a 0W viscosity oil at start up and 20W viscosity oil at operating temperatures.  The Penrite Shelsley Light is a 20W60 oil which may be great for maintaining oil pressure when full operating temperature is reached, but isn't so great when cold. Synthetic oils have the benefit of higher viscosity index.  5W40 and 5W50 oils are available.  Porsche recommends dino 20W50 oils for their 356 and early 911 engines - so you see there are lots of opinions out there! Posted by johnlayzell 15/07/2014 16:25:03

With respect to John's post the idea behind the &quot;tacky additive&quot; is to maintain a film of oil, especially desirable if cars have been standing for an extended period of time . This film is then replenished by the pump upon startup. I appreciate the viscosity of the Penrite oil is higher and this can be an issue if other measures are not adopted.  Richard Posted by RichardWallach 15/07/2014 22:05:14