oil
 

ok, heres an argument with some of my friends. one says that a synthetic will mess up an older engine and the other says it wont. help! i've been running normal 10w30 in my z but want to run syn. i have 30-40000 mi. on the engine, would it be ok to go to syn.?:confused:

It's preferable that you run synthetic. I'm not sure where your friend's reasoning is coming from, but synthetic oil will produce greater lubrication within the engine. Any time parts can move more freely and do so lubricated, the better an engine will run. I think you'll find the most serious Z owners only use synthitic in their Zs. One thing to know however, is that once you go synthetic, you can't ever go back to regualr oil, this can mess things up a bit.

I've always heard that due to the sythetic oil being thinner, it can "find" leaks that conventional oils won't get through in older engines. I haven't changed over due to this thought, even though I have new f/r main seals I am not sure of the status of the upper seals. So I have stayed conventional. Has anyone else heard this?

I've heard about this on several forums and from alot of ppl. Some have experienced leaks after switching to synthetic. Although the leaks occurred, they couldn't justify the switch as the cause. A majority however haven't experienced any leaks whatsoever. If you have new seals and the others don't leak, I wouldn't worry about it too much. The chances of your particular car leaking are really very small. Also, I haven't heard or anyone experiencing any problems from switching back and forth from synthetic and conventional. I've done it without any problems. Oil is oil. Conventional or sythetic more or less DO the same thing which is to lubricate. I don't see why mixing them as some oil manufacturers do would cause any problems.

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