Oil recommendations for 1989 Porsche 944 non turbo

[phlfly]

Hello,
Long time I did not post here, well I back with old car. I like those inexpensive cars with racing nerve; even it will cost to maintain them. But it's not every day car, just one -two days a week, may be autocross.

Well, my biggest question to oil guru guys, what should I use synthetic or conventional oil. I know the grade, summer 10w-50 and winter 10W-40. The car was originally designed for Castrol GTX, well in now days the synthetic is better but would my seals failed on synthetic oil, would cam shaft has enough protection?

And what would you use for 944 turbo cars? Would you go with sythetic since it's better protection for turbo bearing.
Please help.

Thanks

 

[GSCJR]

I would go synthetic in turbo or non-turbo models, either 0w-40 or 5w-40.

 

[phlfly]

Originally Posted By: GSCJR
I would go synthetic in turbo or non-turbo models, either 0w-40 or 5w-40.


So you are thinking the seals will not let go?

I read aboutPorsche was based on high ZDDP, whenever this means?I don't have an idea.

 

[SuperDave456]

Synthetic 5w40 year round.
Better protected if out racing in the heat, better cold starts when it gets cold out.

It will protect everything just fine. Especially any oil cooled turbos.

If you see any leaks, that's just because they were there before but coated in the goo left behind by other oils.
As they are cleaned up by the Synthetics the seals may leak.

However, it also may not leak. It depends on how the seals have been cared for in the past.

As far as the specific brand, check out any name brand.
If you want to know the interval you should run on, stick with one brand and have some UOA's done.

Also, check in on forums specific to the cars you mention. There are typically UOA's available from similar vehicles available.

 

[ARCOgraphite]

I would expect a premium oil like a 10w30 EDGE or PU would be ABSOLUTELY fine for street use - this is a low power density engine.
Why 10w? You are in VA and the less vII in the oil - the better - as far as gum and varnish go on the pistons.

 

[randomhero439]

Rotella T6 5w-40

 

[phlfly]

Why did Porsche recommeded 10W- oil? I know it's not good for cold start, but may be for longer life at 1980's, the oils were higher HTHS at higher W- number.

Thank you.

 

[HyundaiGuy]

I've owned the same car in the past. If I did again, I'd either go Rotella T6 5W40 or Mobil 1 0W40.

 

[79sunrunner]

I knew a Porshe guy who wanted power and fuel economy, and in his his attempts for 1000 horsepower or more, he ran 5w/20.
5w= good start protection

20w= how many miles it lasted

 

[phlfly]

Thanks everyone I will go with Rotella T6 5W40.

So I guess most of you are thinking there is no reason to use GTX 10W-50, when oil like Rottella T6 will do better job.

 

[Garak]

Originally Posted By: phlfly
Thanks everyone I will go with Rotella T6 5W40.

That or Delvac 1 or something similar should work just fine. As for why Porsche called for a 10w-XX, well, look at the year of the vehicle.

 

[Quattro Pete]

Originally Posted By: Garak
Originally Posted By: phlfly
Thanks everyone I will go with Rotella T6 5W40.

That or Delvac 1 or something similar should work just fine.

Yup. I believe Delo Synthetic 5w-40 is also in the same category, and it's under $20/gallon at Walmart in the US. However, M1 0w-40 should work too, and is officially Porsche approved, and is even cheaper than this in the US.

 

[ARCOgraphite]

Again, that engine should not need a 40 grade if its in tolerance - unless you really dont need that 7 HP and improved throttle response you'll be giving up.

 

[Quattro Pete]

Originally Posted By: ARCOgraphite
Again, that engine should not need a 40 grade if its in tolerance

Yet there are no Xw-30 oils on the Porsche approval list. Why?

 

[phlfly]

Is Delo good oil, it's made by Chevron.

Alss the "OW" will be fine for Porsche, was 10W or even 20W.?

Thanks

 

[Garak]

Originally Posted By: Quattro Pete
However, M1 0w-40 should work too, and is officially Porsche approved, and is even cheaper than this in the US.

Quite correct. It's still hard for me to wrap my head around the availability of M1 0w-40 in 5 quart jugs in the States and at the price for which they're sold.

 

[supercity]

M1 5w50 is another option although most likely thicker than necessary

 

[phlfly]

So the "cold weight" is not very important. Why I'm worry it's only camshaft problems, since that motor is more VW/Audi then Porsche, and we are all known the problem with camshaft on VW's cars older models.

 

[phlfly]

Just read about some ZDDP requirements for Porsche 944 oils?
Is it true?
After long read and search it seems to me Castrol GTX is lowered their ZDDP numbers over the years, but Shell Rotella (10W-40) has still higher number.
Is it really important to have ZDDP high for these type of engines, as I read it's protect flat camshaft, but also it said only for breaking period.
Very confusing.
Thanks

 

[Triton_330]

Originally Posted By: phlfly
Just read about some ZDDP requirements for Porsche 944 oils?
Is it true?
After long read and search it seems to me Castrol GTX is lowered their ZDDP numbers over the years, but Shell Rotella (10W-40) has still higher number.
Is it really important to have ZDDP high for these type of engines, as I read it's protect flat camshaft, but also it said only for breaking period.
Very confusing.
Thanks


Most engines run ok with lower ZDDP, but when it comes to German vehicles, I do believe they like the ZDDP. I would recommend the Rotella.