Using Regular Oil Vs Synthetic In 1994 Gs300

[Witty38]

My 1994 GS 300 is approaching 160,000 miles and I have very little if any problems with it. Runs great. I just had a California smog check and the technician said the engine is burning very clean. However, when he found out I was using synthetic oil and changing it every 10,000 miles, he warned me that this will cause the engine seals to start leaking because the earlier years of Lexus were not 'set up" to handle synthetic oil. I, of course, have had NO problems so far. Is this bunk or are those engine seals gonna start leaking sometime in the near future, sooner than if I used regular oil?

[SRK]

It's bunk. Go visit the Mobil1 website and read about the stuff yourself....the mechanic doesn't know what he's talking about. You're smarter than he is - you're using synthetic.

I have a customer who owns an original 69 Ferrari Daytona, and it took me a couple of months, but I convinced him to use Mobil 15W-50 synthetic. That was five years ago. No leaks, runs quieter, revs better, great protection for an engine worth about as much as last years LS430. If the Ferrari is "set up" (whatever the hell that means) for synthetic, the Lexus sure as shootin' is.....

[Scott Gordon]

i have a 93gs300 with 188000mi using dyno as advised by a number of folks its not a good idea to switch with this many miles on as car parts wear based on dyno oil properties. hey 188000 on dyno changing every 3000mi or so and no issues so i say stay with what works you got 166000mi why take a chance how many more years you gonna own car.

[reyesgt02]

i have 260000 on mine using full synthetic 10w30 with high mileage and it seems to runs great on it, you should stay with synthetic