Discussion in 'OT Driven' started by NPT, Jul 1, 2007.
and why is that?
whoever told you that is full of crap
Negative. I've switched numerous times and never had a problem. I prefer synthetic though.
you got lied to sonny.
Natural oil contains two classes of chemicals (not including the added detergents that the oil companies add): poly-alpha-olefins and esters. Polyalphaolefins provide the lubrication, and Esters keep the oil thin. (Without the esters, natural oil would be closer to the consistency of tar, which is exactly what you find inside engines that have sat for long enough for the esters to evaporate.) Esters also cause rubber seals to swell, because of their solvent properties; over time, that persistent swelling causes the seals to wear out where they rub against whatever it is they're sealing.
First-generation synthetic oils contained only the poly-alpha-olefin compounds, because the companies that made them didn't see any reason t include damaging solvents in the oil. (They used thinner PAO compounds than natural oil, so the esters weren't needed to keep the oil thin.) The problem with putting synthetic oil into engines that had always used natural oil quickly revealed itself, though, because the esters that had soaked into the engines' rubber seals would evaporate and allow the seals to shrink and start leaking.
Modern synthetics include just enough esters to prevent oil seals from shrinking in older engines, so it's no longer an issue. As for using natural oil in an engine that used to use synthetic, there's never been a problem with that, but frankly, there's no reason why you should be dumping coal dust and sulphur into your engine when there's a perfectly viable alternative.
I am 600 miles away from my 3,000 mile mark. But I want to change my oil now god damnit.
So do it. And fill it up with Mobil 1.
I've changed my oil after 1000 miles on occasion, if the engine starts to feel a bit sluggish. The manual for every car ever made says to change the oil as often as driving conditions warrant, and if I've been stuck in a lot of hard-stop/hard-go traffic jams in the middle of August with the A/C on full blast, that puts a lot more stress on the engine than cruising in the springtime when everyone else is on vacation and the roads are clear. I could demand that my engine suffer so I can get my 3000 miles' worth of usage out of the oil, but frankly, the lifetime of the engine is more important to me than the lifetime of the oil.