Synthetic vs Regular Oil

New Member first post....
Recently found and bought back my '86 coupe(factory ordered 1/86). Getting ready to change the oil and have been using factory recommended synthetics in my BMWs. Any thoughts on switching over to synthetic after all these years? Any concerns over gaskets, etc.
49,000 original miles.
Current oil pressure ranges between 62-74psi. Seems high to me-is this normal?

Thanks and Great forum BTW!

[aquaholic]

i've done it on many used vehicles that i had and have. harley included. never had an issue. oil pressure guage just probably needs replaced. around 30 i would suspect at idle with a stock pump. 22 years is a long time for one to last.

Thanks for the advice.
You think it's the gauge itself or maybe the sending unit? I've got the atari dash. I know there are issues with those.

[c4c5specialist]

HI there,
If you are ever in doubt, always take a mechanical gauge reading.
Allthebest, c4c5

[whalepirot]

Originally Posted by japicella

Any thoughts on switching over to synthetic after all these years? Any concerns over gaskets, etc. 49,000 original miles.
Current oil pressure ranges between 62-74psi. Seems high to me-is this normal?

Welcome. Great find with such low miles.

My car showed a constant 80 psi for a long time. If your indications are varying, I'd not be alarmed. c4c5 is an awesome tech and his words are always spot on.

You'll get varying, if intense opinions about oil from Vette guys. Mine spun a bearing after a decade + with nothing but synthetic, either Mobil 1 or Castrol. While I like the insurance that they provide in case of a disastrous overheat, I prefer and use only Valvoline single weight in the Vette and '95 735iL and change it and the filter every 5k. The 745Li and the R1100RS use the factory-recommended synthetics.

I feel after hearing from a trusted mechanic, that the regular oils have better lubrication properties and I like the 'cushioning' of the thicker oil. I recall the alarmingly low Mobil 1 pressures (mechanical gauge) back in my Pontiac Astre days. The thinner nature of most synthetics may allow leaks and burning, where there was none before. I've read of a cleansing action with new use, which may cause dislodging of deposits. With the lower mileage of the car that may not be an issue. Perhaps pulling and looking inside a valve cover will indicate just how clean the insides are and offer you guidance.

It sounds like whatever you choose will be fine.

[ChuckG]

Your Vette has an oil cooler, as does mine, being built before GM mandated the switch to cooler-running synthetics and the deletion of the cooler.

I'm a big fan of synthetics in my newer cars, but until I replaced my 160 degree thermostat, I rarely saw oil temps over 200 degrees. Oil must reach 190 to cook off harmful impurities.

My personal experience was that synthetics ran 20-25 degrees cooler than regular oil (both in 5W30 weights).

With my new 190 degree thermostat, I'm usually at the 220 degree mark on my oil and it's much cleaner looking than those few weeks with the lower oil temps.

Thanks for the great responses