Motor oil for 84 928S

[8bender]

Hi guys

I read that many recommended the 20W 50 castrol oil

Which one is better the GTX SAE superior sludge protection or the SAE high mileage ?
Or maybe something else ?

Thank you

[hbueno]

You might as well ask "what is the one true religion?"

Some will say you should always use 20W50 or risk destroying your engine. Others will say 15W40 dino or 5W40 full synthetic is fine. All will agree that higher levels of ZDDP are good. Other than that, I've read about a thousand messages about oil on various forums over the last year and don't feel any more educated than before. And it's not just Porsche nuts, even Corvette and Subaru fans have book length discussions about the holy grail of oil.

You might want to read some of the oil threads for fun, but ultimately it's your decision what to use.

Hugo

[Landseer]

Mobil 1 15W-50 is popular with 928 guys.

Valvoline VR1 20 W50

Brad Penn

Royal Purple

All supposedly have the old-style elevated Zinc to lubricate the lifter/camshaft interface.


Most regular oils have jetisoned it due to compatibility, i've read, with new style cat converters.

[curtisr]

Lindsey Racing sells a ZDDP additive: ZDDPlus ZINC ADDITIVE at LINDSEY RACING - Your Porsche Performance Parts Center

[harborman]

Look at your manual. It all depends on where you live and outside temperature. I use 15W40 here but if I were in a colder area or warmer area I would change viscosity depending on time of year.

[8bender]

Thanks guys

[Big Load]

hi
I'm in london where the weather is not to great but I'm using 0 /40.
I thought I'd try this and see what it does. Don't know what other ppl think of this

[Big Load]

thats 0w40

[924CarreraGTP]

Castrol GTX 20W40. I swear by it for any Porsche engine. I run Rotella 15W40 in my 911, but most everything else I run Castrol GTX. Synthetics are not good for old engines unless they've always used them. They are rumored to cause leaks on old engines. This is pretty common knowledge for motorcycle people, not so much car people.

[Landseer]

I only use Mobile 1 15/50 synthetic on 4 of them. No leaks.

[Pete R]

Originally Posted by Big Load

thats 0w40

I use a 5w-40 or 0w-40 depending on brand of synthetic. Works great. No leaks. I use Amsoil and change it every 2 years. I put on under 2500 miles a year and Amsoil has an additive package that will go that long. I used to run the 20-50 but I can have some really cold mornings come Nov-Dec so I thought the 5w-40 was a little better for me.

[MPDano]

15/40 Royal Purple, but apparently my 928 is a diesel

[curtisr]

Originally Posted by MPDano

15/40 Royal Purple, but apparently my 928 is a diesel

Ha! Ha! Ha!

[harborman]

I think we covered the oil issue a few times already, already, already!

[924CarreraGTP]

I could see something a little lighter being good if you lived some place cold all the time. It's pretty warm here most of time. My garage doesn't get under about 40 degrees or so even in the cold winter. I use Castrol GTX 10w40 in 944s.

[Reddog2]

I use Mobil 1 15W50.

[waynestrutt]

Originally Posted by Pete R

I use a 5w-40 or 0w-40 depending on brand of synthetic. Works great. No leaks. I use Amsoil and change it every 2 years. I put on under 2500 miles a year and Amsoil has an additive package that will go that long. I used to run the 20-50 but I can have some really cold mornings come Nov-Dec so I thought the 5w-40 was a little better for me.

How does oil achieve a viscosity of 0?, and why would you want to risk using it? Just follow the owners handbook and add the zinc. Used 20w-50 in every vehicle since 1960. Never ever had an engine failure or starting problem caused by too thick oil. I live in "The Great White North" where winters can see 40 below or lower.

[Pete R]

Originally Posted by waynestrutt

How does oil achieve a viscosity of 0?, and why would you want to risk using it? Just follow the owners handbook and add the zinc. Used 20w-50 in every vehicle since 1960. Never ever had an engine failure or starting problem caused by too thick oil. I live in "The Great White North" where winters can see 40 below or lower.

A 0w-40 is a 40 weight oil that has a flow characteristic of a 0 weight oil at 32 degrees (I'm not sure of the degrees but it's a cold flow characteristic). It is NOT a 0 weight oil. It is actually better than heavy oils at start up (when 90% of engine wear occurs) due better flow. Flow is the most important aspect of motor oil, it's what is keeping the layer of oil between metal parts.