I have a 1990 Lincoln with 94,450miles on it and it has been maintaned well and oil has been changed regularly, But now as the miles get  higher I hear that the synthetic oil is the way to go is this a good idea or is it dangerous for a engine that has always had regular oil and at that mileage? I would like to put in the syn.oil for I read it is better and helps the engine to last longer and smoother? Is this the truth of a sales pitch even though I hear from people that have changed, can someone give me the REAL truth and if I should do it the next time I change the oil and if there is any tricks I should know about doing this the right way along with the filter, and should anything else be changed at that time to help the engine ajust to the new "Blood" so to speak, Thanks to who ever answers this.   

 There's no issue switching between--or even mixing--synthetic and organic oil...with a properly maintained vehicle, that is.

As synthetic MAY free up some sludge, it would be a good idea to change oil filters after about 500 miles and cut it apart to see how clogged it is.

However, if you do change your oil regularly and haven't hot-rodded your engine, a top quality organic oil or a synthetic blend should be more than adequate. I wrote an article that appeared on Valvoline.com. Check to see if it's there.

dude man do what you want but its more trouble than its worth yeah it will run fine first but as it frees up that sludge its going to get clogged in your oil pump filter and can cause your stuff to blow

I believe that synthetic all are very good oil but very expensive what is important is that you change the oil on time always.

if you are worried about the sludge before changing your oil drain a quart and a half out add a quart and a half of paint thinner or kerosene,paint thinner work better,let the car idle for 5 or 10 mins.drain oil replace with oil of choice.i dropped my oil pan and clened it out good also.i put royal purple in mine runs great.

painter969:

if you are worried about the sludge before changing your oil drain a quart and a half out add a quart and a half of paint thinner or kerosene,paint thinner work better,let the car idle for 5 or 10 mins.drain oil replace with oil of choice.i dropped my oil pan and clened it out good also.i put royal purple in mine runs great.

In good conscience, I could not let the above advice go unchallenged. Automotive and lubrication engineers the world over would warn you of the dire consequences possible if such recommendations were implemented. Without going into pages of details, I'll focus only on a single point here, i.e. one of the primary functions of modern DETERGENT MOTOR OIL is to maintain contaminates in suspension for the oil filter to capture and prevent further circulation throughout the engine. By following the above recommendations, two engine-destroying events may occur: (1) an oil filter that is immediately plugged and disabled by dislodged sludge which continues circulating via the filter's bypass and (2)  severely diluted motor oil with reduced lubricity and viscosity circulating through bearings, around rings, over cam surfaces, etc. etc. The scenario is not a pretty one! Back in the ol' days of non-detergent oils and no oil filters, it was commonly thought that 'mouse milks' and other engine flushes/additives were beneficial to engines. Fortunately we are better informed today about the proper treatment of the precisely engineered, not to mention expensive, engines in modern vehicles.