it is time to change my oil again in my z. i have already talked about going to synthetic to the guys over at 300zxclub.com. i was worried about people getting oil leaks when they switch over to synthetic oil, they said it was because with old oil seals, there is dirt that acts as part of the seal and synthetic oil cleans that dirt, which makes it not seal anymore, which causes an oil leak. so my question is, my seals were replaced 15k miles ago, are the seals still new enough to not be affected by synthetic oil? thanks.

-Jared

Jared, it depends on the conditions your running in. Myself I've been using Redline from the start and never had any problems. When synthetic oil first came out, got a bad name for that very reason (leaks). I've never had a leak problem.

I'm sure that if you recently had all seals changed... it would not be a problem. It's a bit more expensive of course but your oil lasts longer... just be sure not to inter-mix brands or go back to regular oil...

I've been running Valvoline full synthetic since i got my car 12k miles ago, I havent had any leaks, runs better, less tapping on cold starts on below or near freezing mornings, and I am getting slightly better milage. ((like 1 MPG more on the highway)) I run 5W30 in the winter and 10W30 in the summer. I have still got the seals that were on there at the 60k service oh 50k mile ago..... no leaks yet.

Now to fix that transmission leak.

tell us how it goes freaky-deak!!!

sweet, i am going to use it, i just bought some Mobil 1 10W-30. i am just afraid of getting leaks because right now, everytime i check my oil, my level NEVER EVER goes down, i mean i probably loose more oil by checking it then anything else.

-Jared

Use MOTUL synthetic... just like the JGTC Fairlady Champions!

i used a oil made for cars with over 70k miles on it, cant remember who made it i think valvoline ... either way its a pretty good idea to use it instead of synthetic if you havent changed seals for awhile dont you guys think so too ?