I have a '94 deville with the 4.9liter engine and was thinking of going to mobil synthec oil my next oil change. The problem is I've heard from a few people that if you've nevr had sythedic oil before that it will ruin my engines seals is this true? Right now my car dosen't leak anything so I'd like to keep it that way if there is any truth to this? I have 117,000 miles on it and wasen't sure if synthec oil is the way to go? I mean I guess my car dosen't have high milage for the year but is it worth it to switch to the mobil 1 syntec?

With that many miles I probably would not make the switch. The synthetic is not going to ruin anything, but it does seem to have more of a tendency to find places from which to leak if the system is not solid throughout.

I have run synthetic in all of my vehicles for over 30 years.

G

:hide: Boy is that a loaded question. Synthetic is not neccassary, but will not hurt anything. Do a search for synthetic (or Amsoil) and read up on the oil wars.

You can switch to synthetic just make sure you don't have any leaks. Synthetic has smaller molecules so it can flow faster and which is why it finds a way to leak out faster. It will not hurt the engine in anyway whatsoever if you switch now.

I mean I guess my car dosen't have high milage for the year but is it worth it to switch to the mobil 1 syntec?

NO! Do you have some reason to switch to synthetic? It costs substantially more and in normal usage is not needed. Is there something in your usage that makes you think dino oil is not sufficient?

Here we go again lol. I'll further support that putting in synthetic will not harm it just because you have used dino before. I personally switched to synthetic. All that's been said is true... My opinion is think of synthetic as "padding" the threshold of engine wear. My favorite analogy to use here is that it's like speakers. Let's say you have 500 watt speakers (these are arbitrary, and it's an analogy, don't get me into the ohms and such lol) in a living room. Do you need 700 watt? No... Will they last longer? Probably not much... Though you may notice a slight difference in the clarity of sound... MINOR distortions that your ear can hardly pick up will seem more clear....and if you blast them for the neighbors or something...the harder use, you'd notice a little more difference/worth for them. Same with synthetic oil. You're increasing the threshold. You will not normally exceed the dino oil threshold, but just because you're giving it more, you might experience the slightest of differences, if any...and perhaps the engine will run a little cleaner since there are less traces of the larger molecules that break down into sludge.