One mechanic who services my 2000 Ford Windstar 3.8 van says I should use a max-life oil (syn blend) because it has 116K miles. Another mechanic says absolutely not because it’s an ‘old fashioned engine’ and a max life oil would actually cause leaks. I trust both men, but I need this van to last a long, long time.
It has already lasted a long time…Forget “Max-Life”, it’s time for “High Mileage” 
Frankly, as long as you are using a oil that meets the original requirements for your car, you should be fine, until some problems may develop. If it got to 116,000 using what you have been using and there is no sign of a specific problem at this time, there is no need to change what you are doing.
Many of today’s cars need synthetic oils. In general older cars may use synthetic oils, but will not really see any benefits compared to conventional oils.
If and when you car starts using more oil, then I would recommend a high mileage oil to reduce that usage. Other than that, don’t worry.
Keep using the same oil that got you to 116K miles. There is no need for any oil with “special” names. It’s just marketing, and maybe a bit of extra profit.
Use the oil specified in the owner’s manual. If there were some mileage point at which a “special” oil became necessary the owner’s manual would tell you. But it doesn’t becuase there isn’t.
Max Life and other high mileage oils have some extra additives in them that may or may not help out your engine. If you are consuming oil due to seal issues, then these oils might help, because the additives try to expand the seals. You have to try them and find out.
On the other hand, if you have low or normal oil consumption, these oils may not help out at all. The peculiar thing about the second mechanic’s statement is that Max Life and hight mileage oils are marketed at “old fashioned” engines, because those are the ones that have over 75K miles of use, usually. I would hate to think what he thinks my 95 Ford F350 V8 is, an antique?
My son also has a 2000 Ford Winstar with the 3.8 engine. The engine did fine until about 138,000 miles when it began to consume oil. He switched to a high mileage oil and claims that he hasn’t used any oil since. If you are’t using oil at this point, stick with the oil specified in the owner’s manual. If you do start to use oil, then consider a high mileage oil.
Again, as everyone else said:
If your van is using oil, then try one of the high mileage oils, to see if it will reduce the oil consumption AFTER you have the PCV valve replaced. A faulty PCV valve tends to be one of the most common reasons why engines suddenly start consuming oil later in their lifetime.
If your van is not consuming oil, just keep using the normal oil, in the proper weight that you have been using, and all will be good with the engine.
BC.
Methinks mechanic #2 is an “old fashioned” mechanic. Some of what he knows is still steeped in myth and mystery.
What you should be using is oil that meets the specs in your owner’s manual and nothing else.
For the record, synthetic and dino oils are chemically exactly the same. The differences are that synthetic has (allegedly) more consistant sized molecules and is purer. Blended oils are simply the two mixed together. Www.carbibles.com has a good primer on oils. I recommend a visit.