--- In dmcnews@xxxxxxxxxxxxxxx, Senatorpack@xxxx wrote: > > Is Mobil one synthetic better than conventional oils? > > My BMW's (and other European Cars) have a decal attached under the hood "requesting" the use of Mobil One synthetic. > > The BMW dealers use zero 0w/30 oil. > > Michael Pack >From many pages online both by Synthetic oil manufacturers, and 3rd parties, all agree that Synthetic oils do indeed have benefits over conventional motor oils. Specificly, the benefit is increased resistance to wear within various categorites, which in turn leads to longer engine life & $ savings. Now as a disclaimer, I'm no ASE certified mechanic, these are just paraphrases of simular claims by both regular people, and synthetic manufacturers that I've found on the internet (and of course if it's on the internet it must be true, right? :p), as well as other sources. So if somthing is wrong here, please correct me. 1.First of course is that synthetics have longer intervals between oil changes. This is the biggest factor of all that offsets the higher price ( the biggest turn off for DeLoreans due to how much we use!), if not make them cheaper according to some. 2. Syntheics don't nessisary lubricate "better" per se as they can lubricate quicker because of a better flow when either hot or cold. And of course the next reason... 3. Synthetics are even more resistant to breakdown and oxydation due to extreme temperatures and harsher environments. 4. And of course there are the other things such as resistance to contaiminates, less wear on components, and improved fuel economy due to less resistance. The only disadvantage I've seen is the "older seals can develop a leak issue". Synthetic doesn't damage oil seals, but since it flows easier/has smaller molecules, it can flow thru smaller cracks in seals where conventional oil would not have. As far as this goes, I've seen an even split between people who've actually switched to synthetic (vs. those who "know" someone who has) that this will or will not occur. I'm assuming there are other variables though that have contributed to this, so I'm still not 100% convinced that leaks will or will not occur. Now if you have a vehicle that specificly requests the exclusive use of synthetic oils, then you do definatly need to stick with them. Newer engines that require specific types/grades of motor oils do so because they are engineered specificly for them. Anything other than these stated can reduce econmy, and increase wear, aside from even voiding the vehicle's warranty in some cases. As was explained to me, some newer motors can have smaller ports where the oil passes thru than previous, and the wrong oil will not be able to flow thru as fast causing less lubrication. Now as to which type of synthetic motor oil to use, who knows. Apparently some petrolium companies are changing the definition of "synthetic oil", so I've no clue. However, I can tell you this. When you buy synthetic oil, watch out for that "Multi-blend" stuff. It's just regular oil with a little synthetic blended in to up the price a bit. That it itself defeats the purpose of using synthetics. -Robert vin 6585 "X"