Good running motor use synthetics, if its junk feed it junk.
Synthetics are the best way to go. The reason people think they need to “change over” is from the media. The reason people say synthetics leak is not true at all, unless. Yes you knew it was in there! Synthetics are pure, clean and formulated (speaking for Amsoil only here) there for yes they can be easier to leak since they do not sludge up. Once a seal leaks sludge forms at the leak from the difference in temp, pressure, and a mix of other reasons. That sludge will help a bad seal or destroy it. Synthetic oil does not sludge so it will leak as a result of a bad seal. If you have something wrong don’t you want to know about it? Inspect your vehicles often is key to keep ahead of issues such as bad seals or worn parts. The synthetics will not make a leak! But they will make a problem known. Most of the time people don’t have problems with their engines so it’s a good idea to use the best products for your application. Do not use an oil thickener or stabilizer, it will hurt your lubrication in your engine from lack of oil flow and make hot and cold spots. And you can’t fix a problem by putting in more additives over junk oil.
And if you have an old motor with bad, old oil and you use a synthetic it might burn some oil. Why? Your piston rings have old dirty build up around them. Once the clean oil takes out those deposits your rings will not fit the cylinder 100%. After about 500 to 1000 miles the rings will seat to the clean cylinder and you will be fine. It all depends on how dirty your oil was to start with. Now Amsoil offers an engine flush to run in you motor before you change your oil to clean the motor. (It is a detergent, if you use convention oil there is a detergent in it to keep it from making sludge and will not hurt your motor. Not for use in motorcycles with wet clutch.)
I do not use conventional oils due to the paraffin’s in the oil from the hydro cracking process. The paraffin’s are like a wax at cold temps. That wax is hard when cold and is very bad in your motor! A hard wax being spun around your crank bearings makes me shiver like nails down a chalk board. Oh, and some paraffin’s are also in diesel fuels, that is one of the reason it gels up in the cold! That is why I also offer Amsoil Cold Flow for diesel fuel. Also you have to love the use of Low Sulfur Diesel Fuels. The sulfur can help lubricate the fuel, good for your high pressure fuel pumps and injectors. A bottle of Diesel Concentrate will help with that also.
If you cannot see the issue here it is with the manufacture of the products we rely on. The convention oil is not up to today’s standard, nor was it really ever up to par to what we should have been using but it’s a money issue for the big companies. The same problems we see in our fuel, its being cut with other products for emissions and cost reasons, but it’s not the best products for our use. Once you understand the corporations plan to just build it and people will buy it because of marketing and money management you want to dig deeper into better products for your needs. So synthetics or not it’s up to what you trust. You could dig and dig on the subject but you will see synthetics such as Amsoil are the best since they are uniform, clean, and proven. Why does Amsoil say some oil products last up to 25,000 miles or one year? Because it can! Why would you buy a jug of Rotella or Mobil 1 (By the way Mobil 1 is not a full synthetic, call them) and change it every 3,000 or 7,500? Waste of time, money, and life of your engine.