Oil Change: Synth back to Dead Dino

[Jp-oh]

My car had some engine out service in the winter and the shop put synthetic oil in on the fill. I am getting ready to do a change and want to go back to the Brad Penn I was previously using. I can't imagine that, after draining the oil as best I can, that what ever residual synthetic is an issue. True/False? Sorry if this is a lame and or paranoid question.

Cheers.

[J-Mac]

According to Porsche, and their new range of classic oils, engines up to 2.7 use dino and 3.0 up use synthetic.

10W-60 for the 911 from a displacement of 3.0 litres - Time for an oil change - Product Highlights - Dr. Ing. h.c. F. Porsche AG

[porschenut]

The last TSB from Porsche called for Mobil1 0W-40 for all model years 84-up.

As far as Brad Penn, the 20W-50 that most guys are using is partial synthetic. Even if it were 100% dino, there is no problem mixing dino and synthetic so you have nothing to be concerned about.

[COLB]

Originally Posted by J-Mac

According to Porsche, and their new range of classic oils, engines up to 2.7 use dino and 3.0 up use synthetic.

10W-60 for the 911 from a displacement of 3.0 litres - Time for an oil change - Product Highlights - Dr. Ing. h.c. F. Porsche AG

So...umm...does this mean Porsche is a non-believer in the requirement for ZDDP to reduce cam wear on flat tappet engines?

Or do they just want to make money selling oil in pretty cans.

[awhnry]

Synth or dino is not as important as the additive package. Synth tends to run cooler so I prefer it but to date, I have run only dino or a blend in my 911. My spring oil change was to BP but if I dont like it, I will probably go to Valvoline VR-1 due to availability. So far heat hasnt been an issue so I think again that the additive package is more important in this instance.
The GTO and Speed6 get synth; the hydralic valve adjusters on the miata prefer a thicker oil but solely for noise issues. I used to run used race oil in the Excursion since I changed oil every other weekend in the race car(RX-3 using Redline 30w).

[Jp-oh]

Originally Posted by porschenut

Even if it were 100% dino, there is no problem mixing dino and synthetic so you have nothing to be concerned about.

Noted, thanks porschenut.

[hbueno]

Originally Posted by Jp-oh

Noted, thanks porschenut.

There's no distinction, it's all dino. The only difference is the degree of refining - "synthetic" is just more highly refined dino oil.

Hugo

[Dodge Man]

Originally Posted by Jp-oh

My car had some engine out service in the winter and the shop put synthetic oil in on the fill. I am getting ready to do a change and want to go back to the Brad Penn I was previously using. I can't imagine that, after draining the oil as best I can, that what ever residual synthetic is an issue. True/False? Sorry if this is a lame and or paranoid question.

Cheers.

There is always some oil left in the system due to design so do a short interval change if the oil stays smelly & nasty. Just get the high level of ZDDP to keep the rocker arms & cams happy. Dino or Syn is a question of seal compatibility for most. However, if you look at the mechanical pressure from the cams to the rockers the ZDDP level comes to the front. 911 air cooled motors put a very high pressure on the rockers & cam lobes. You may want to look at the ZDDP threads. FFT Even though newer oils have "replacement additives" for ZDDP the newer oils are for newer cars that usually have roller tappets anyway. Racing oils usually have sufficient ZDDP so that is why many recommend them. IMHO Start with VR-1 Valvoline or Brad Penn data. Just remember that oil companies will change additive packages without notice so stay on top at every oil change. Best of Luck.

[T77911S]

paranoid

[T77911S]

he was asking if the residual synth oil was a problem when going back to dyno