I purchased a publication from the Noria Corporation which specializes in lubrication consulting and educational work. The publication is authored by Jim Fitch who is reportedly a very reputable engineer who has even been used by major oil companies as an expert witness on lubrication issues. The title of the book is "How to Select a Motor Oil and Filter For Your Car or Truck.
Having read this book I am left with the impression that while my warranty requires that I use 0w20 synthetic oil I would probably have better protection for the engine if I used 5w30 synthetic in my 2013 Mazda 3. To me, the author was very careful to put in statements advising the readers to follow the manufacturers recommendations for his/her particular vehicle but throughout the publication I got the distinct impression that todays thin oils recommended by the manufacturers are more for CAFE than anything else. I was also left with the understanding that the 0w20 oil robably offers adequate protection for at least 100,000 miles providing my engine's thermostat doesn't stick or I don't start using it for some sort of severe service like hauling a trailer in the mountains.
Of course, I can't quote the entire publication but here are a few inferences that were provided: In one part, the book notes that 5W-20 viscosity compared to a thicker oils can translate to fuel savings ranging as high as 5 per cent, depending on additives and driving conditions. In that light, the publication added the following: "However, beware that such a viscosity selection may retard engine life, (see Chapter 7 which discusses the issue in more detail)". Also, in another part of the selection process for motor oils it recommends: " For maximum engine life select a back number viscosity of 30 for most late model automobiles". Also, under the publication's heading of "What to Use", it states: "Oils recommended by the auto manufacturers seem to compromise protection from wear under severe conditions to gain fuel economy and catalyst durability. It is important to recognize that to use a product that offers more protection from wear will most likely compromise your warranty." Later it goes on to state: "The best protection against wear is probably a product that is a little thicker (such as SAE 10W30 or 15W40) and has more antiwear additives than the oils that support the warranty." That segment finished by stating: "The best oil for your vehicle depends on your driving habits, the age of your engine and the climate you drive in, but it is not necessarily the type of oil specified in the owners manual or stamped on the dipstick."
As I noted, I don't have enough knowledge to argue the merits of this issue and maybe I don't have enough knowledge to even come to the right conclusion after reading the whole publication. All I can suggest is that anybody really interested might go to the Noira Corporation website and purchase it online.
Having read this book I am left with the impression that while my warranty requires that I use 0w20 synthetic oil I would probably have better protection for the engine if I used 5w30 synthetic in my 2013 Mazda 3. To me, the author was very careful to put in statements advising the readers to follow the manufacturers recommendations for his/her particular vehicle but throughout the publication I got the distinct impression that todays thin oils recommended by the manufacturers are more for CAFE than anything else. I was also left with the understanding that the 0w20 oil robably offers adequate protection for at least 100,000 miles providing my engine's thermostat doesn't stick or I don't start using it for some sort of severe service like hauling a trailer in the mountains.
Of course, I can't quote the entire publication but here are a few inferences that were provided: In one part, the book notes that 5W-20 viscosity compared to a thicker oils can translate to fuel savings ranging as high as 5 per cent, depending on additives and driving conditions. In that light, the publication added the following: "However, beware that such a viscosity selection may retard engine life, (see Chapter 7 which discusses the issue in more detail)". Also, in another part of the selection process for motor oils it recommends: " For maximum engine life select a back number viscosity of 30 for most late model automobiles". Also, under the publication's heading of "What to Use", it states: "Oils recommended by the auto manufacturers seem to compromise protection from wear under severe conditions to gain fuel economy and catalyst durability. It is important to recognize that to use a product that offers more protection from wear will most likely compromise your warranty." Later it goes on to state: "The best protection against wear is probably a product that is a little thicker (such as SAE 10W30 or 15W40) and has more antiwear additives than the oils that support the warranty." That segment finished by stating: "The best oil for your vehicle depends on your driving habits, the age of your engine and the climate you drive in, but it is not necessarily the type of oil specified in the owners manual or stamped on the dipstick."
As I noted, I don't have enough knowledge to argue the merits of this issue and maybe I don't have enough knowledge to even come to the right conclusion after reading the whole publication. All I can suggest is that anybody really interested might go to the Noira Corporation website and purchase it online.