I hate arguing when Hotrod Lincoln is posting. I look forward to his posts and I find them reliable. I do believe in the use of synthetic oils in the cold temps of South Dakota. But for your old truck, I'm not so sure it would be beneficial or cost effective.
I found this article which does seem to make sense to me.
Here is the link:
http://car-reviews.suite101.com/article.cfm/synthetic_oil_vs_conventional_motor_oilHere is the text:
Dealerships, auto repair shops and fast lube facilities will often recommend using a synthetic oil when a vehicle is brought in for an oil change or routine vehicle maintenance. Naturally synthetic motor oil is much more expensive than conventional oil, so before making a decision, find out the differences between synthetic and conventional motor oil and what it mean to a cars engine.
What is Conventional Motor Oil?
Conventional or regular motor is processed from crude oil out of the ground. The crude oil is separated at the oil refinery. The thicker oil is used for applications like roofing tar and asphalt. The thinner oil is used for applications like gasoline and engine oil, among other applications.
This oil becomes the base stock for the oil. Engine oil base stock refined from crude oil contains small amounts of natural contaminants that can’t be removed from the base stock used in processing engine oil.
What is Synthetic Motor Oil?
There are two components to synthetic motor oil:
1. Base Stock - Unlike conventional motor oil, synthetic motor oils base stock is artificially created or synthesized. Because of the higher purity of synthetic oil, the properties of synthetic motor oil can stand up to heat much better before breaking down than conventional motor oil. Synthetic motor oil can also withstand colder temperatures better than conventional motor oils. This a huge benefit when an engine is first started in cold weather.
2. Performance Additives - Beside the base stock, performance additives are added to both conventional and synthetic motor oils. According to Castrol, the performance additives used in synthetic motor oils are engineered with special additives that help to fight off sludge and mineral deposits that are naturally caused in combustion. Performance additives in synthetic motor oil provide superior protection in extreme driving conditions like extremely cold or hot temperatures.
Pros and Cons of Using Synthetic Motor Oil
Pros
• Synthetic motor will increase the life of an engine
• Longer oil change intervals, because of viscosity breakdown
• Better for extreme driving conditions, especially extremely cold or hot weather.
Cons
• Synthetic motor can cost up two three times more than conventional motor oil.
• Should be used in the beginning of the engines life (after 5,000 miles preferably) not if the vehicle already has a lot of miles. .
• Probably should not be used when the vehicle is brand new due to engine break in of the factory oil in many new vehicles.
Is Synthetic Oil Better Than Conventional Motor Oil?
There’s no doubt that synthetic oil is better than conventional motor oil. Since synthetic oil is made with smaller molecules and less impurities it’s just a plain better lubricant. It’s especially better for today’s modern engines that have tighter tolerances and smaller oil passages that need a super lubricant. Car manufacturers are requiring that synthetic oil be used more and more. Most new vehicles are at least required to use a synthetic blend.
If synthetic oil is used, it’s advisable to use it after the engine break-in period. If the vehicle has a lot of miles, it’s not recommended that synthetic oil be used. If someone plans on keeping a vehicle for a long time, using synthetic oil is a good idea. On the other hand, if someone gets a new vehicle every year, why have the added expense of synthetic oil.
