Possible gasket and seal leaks and definitely not designed for very low viscosity oils. Why spend the money on synthetic oil? When was the last time you have heard of an engine failing because it was serviced regularly but used name brand Dino oil? One day less than never! LOL Besides, most all oils today, including those we call non-synthetic, have synthetics of some sort in them. I am not advocating the use of Dino oils in today's modern engines designed to operate with synthetics, just for our older gen engines.
Drewpy,
As I said above, I do believe SynBlend oils are good because they give some of the best of both worlds but they are very difficult to find now in the U.S. I have used Castrol SynBlend in the past but it is not found easily today. Besides, if you are so inclined, you can make your own SynBlend oil.
Oil is one of the "Hot Button" topics on any motor forum. All of us have our opinions and preferences. Unfortunately, these are often subjective opinions and not based of the facts from the oil industry as well as independent research into oil formulations. I use Valvolene Blue Diesel oil at this time because analysis shows it to have almost as much anti-wear additive as racing oils and considerably more than other Diesel oils. I have used other brands, like Shell Rotella and Penzoil, in the past. You won't have engine failure with any name brand oil but some are just a little better than others. I do not advocate the use of Diesel oil formulated for the modern high performance, low pollution Diesel engine. These oils are dramatically different from the Dino based 15W40 oil I am advocating and not suitable for our older engines. Some folks just can't seem to get past the word "Diesel" when they look at these oils, thinking that oil could never be suitable for a gasser. I just like to see folks make a decision based on facts, not opinions.
Nuff said, I will get off the soap box! LOL
