['97ventureowner]

Originally Posted by 2string

Are you saying don't use synthetic on vehicles with more then 25,000 on them?

I wouldn't use synthetics on an older/high mileage engine as leaks are prone to develop since the synthetic cleans sludge from the inside of your engine.

I like synthetics because of their protection of the internal parts of the engine is better, and as also stated before , the longer change interval. O still change my filter about halfway through the "service life" of the oil (anywheres from 5,000 to 6,000 miles,) and top off the oil to compensate what was lost from changing just the filter. I believe that using synthetics has two good results. 1) It can reduce our dependency on foreign oil in that we aren't changing our oil so much that we continue to increase demand for it, and 2) Since were not changing our oil every 3,000 or so miles, we are actually reducing the amount of waste oil we generate and thus have to recycle , or disposed of improperly in the environment,(yes there are people who still dump there oil wherever they can ) I'm not a conspiracy theorist, but I have to wonder if these companies that produce the oil we use in our vehicles lobby the car manufacturers and other "experts" in the field to continue to recommend the 3,000 mile oil change to keep their profits up. There has been major technological advances in both engines and oils in the last decade and one would think with these improvement, you could lengthen the time between oil changes. Granted , some manufacturers and "experts" are now advocating longer change intervals of 5 and 7,000 miles, but could you imagine if everybody started using those figures for oil changes, the amount of money these companies that produce it would lose?They wouldn't go for it. Just my