going to synthetic oil?

[Rainbow Bridge]

Aloha All,

Our 91 Previa...(her name is Eleanore......we bought her new)....with 187K keeps asking me if she should go synthetic oil...;)

I've always used standard 10W-30 and never did synthetic because It was too much trouble to flush the reservoir.

So was wondering if anyone here had switched to synthetic .........and did u see a real benefit?

Thanks,
Russ

P.S. In my 65 years, I've had Vettes, mercedes, Dodges, Honda, Caddis, plymouths, fords, chevys, VW, you name it.....but by far this 91 Previa is my fav. Can't explain it...she is just a great car, and after 29 years...a family member...

[apham8]

Yes, the Previa is really a great vehicle. Unfortunately, parts are phasing out for them. Maybe the aftermarket will fill in the void where Toyota has phased out parts? Aren't these much more popular elsewhere in the world? Wonder if there may be a source for parts somewhere outside the US.

Anyways, as far as going to Full Synthetic goes there are various opinions regarding switching over after many miles. Some say that Full Synthetic motor oil very well may accelerate oil leaks because of the high detergent will clean the seals to the point where oil will get pass them. There may be an answer to that by going with a Full Synthetic High Mileage version, which has conditioners for seals in an attempt to preserve them.

I personally run a Full Synthetic High Mileage motor oil. I have had great results, but I did change over after a JDM engine swap with low miles. Also, the seals were redone before installation, so I don't think my experience is like yours.

To be honest, I wouldn't switch over at this point because I am of the belief that Full Synthetic is beneficial when used over time. I guess it depends for you based upon how much longer you want to run your Previa.

[Previologist]

i don't have anything scientific to add. I always used trop-arctic synthetic blend in my 91. It suddenly (and temporarily) became unavailable where I lived so one time I used Pennzoil. The engine seized very soon thereafter. It had 330,000 miles

There were other suspicious circumstances. I had an empty 5 gallon gas can in the passenger seat the night before it seized. It was gone that morning. I drove 2 miles and that was all she wrote.

It made me wonder if someone had put something in my gas tank, but I will never know. There were metal shavings in the oil so I don't think it was foul play. I think it didn't like the sudden switch to Pennzoil.

[blakebecker37130]

I have used Mobil 1 on all my vehicles regardless of what oil was used before.
when I replaced the valve cover gasket on my 93 LE, the internals were super clean. No sludge or caked on grime anywhere. The internals were stained oil color, but this is normal.I did this job after multiple synth oil changes. Changing to synth did not seem to cause any oil leaks. Also, conventional oil is compatible to be mixed with synth, so no need to drain the reservoir. If you must flush the reservoir, just drain the oil and turn the key to the on position. Do not start!, this should trigger the reservoir pump to pump the oil to the pan. Drain that and refill everything with synth. Done.