The Oil Thread

[OzJustin]

Hi all

Looking to do an oil change on my S2 in the not too distant future and wanted to get some recommendations on oil. I know these cars need a good amount of ZDDP and the correct viscosity rating. With blends constantly changing and different offerings available in different countries I wanted to get some current aussie recommendations on products readily available here.

My car is primarily a street car and I don't tend to put many km's on (maybe 5k km every 12 months).

Some recommendations I've spotted on Rennlist and Pelican Parts:

Valvoline VR1 Racing Oil 20w50 (there seems to be a silver conventional bottle and a black synthetic version?)

https://www.autobarn.com.au/valvoline-vr1-racing-10w-40-oa01234

Nulon Street and Track oil 25w60 (is this appropriate for a street car?)

https://www.autobarn.com.au/nulon-25w-60-street-track-engine-motor-oil-st25w60-5

 

While we're on the topic, what oil is everyone running in their gearbox/diff? I understand the front engined cars use brass synchros. Recommendations welcome.  

Redline MT-90 75w90 GL-4?

https://www.redlineoil.com/product.aspx?pid=46

 

[Pauly]

Engine oil: Penrite HPR30 (i buy a 20L drum because it's cheaper then buying 2x 5L bottles)

Gearbox oil: Penrite Trans Gear 75W-90 (2L bottle)

I think i had redline in it last time, i cannot remember, but Bursons didn't have it so i got Penrite instead. So far so good. 

[LeeM]

Penrite. Buy Australian ?

[Timm]

I'm running Penrite HPR30 20w-60 in mine as well....though I've never come across a 20L drum of it, I always buy it when it's on sale at supershit or autobarn.

In the gearbox I'm running Mobil 1 75w90 LS.

[Buchanan Automotive]

With the manual transmission oil ( transaxle 944, 944S, 951 , 944S2 , 968  ) it must be the higher shear strength GL5 which is a EP ( extreme pressure rating )  , Porsche updated their recommendation to GL5  25 - 30  years ago 

With the engine oil viscosity for Australia ( climate )  20w-50 or you can use 25w-60 , but we mainly use that for  "club" track events 

So if one was to use ( say ) a Valvoline Racing 25w-60 for road , thats OK , but with the lower detergent ( road oils have a bit more detergent ), I would change it more often , say every 5,000kms instead of every 10,000kms for road conditions

But remember , if you go to the track for a club day , change the oil a lot more often 

Regards

Bruce Buchanan  
Buchanan Automotive 
 

[HH1]

With the engine oil viscosity for Australia ( climate )  20w-50 or you can use 25w-60 , but we mainly use that for  "club" track events 

So if one was to use ( say ) a Valvoline Racing 25w-60 for road , thats OK , but with the lower detergent ( road oils have a bit more detergent ), I would change it more often , say every 5,000kms instead of every 10,000kms for road conditions
 

 

Bruce, what engine oil would you recommend for a 89 928 S4 auto. Thanks. 

[Buchanan Automotive]

I try not to recommend brands , but in the owners manual in every last century Porsche , be it   Air Cooled 911 , 928 ( ALL ) , 944 ( ALL ) Porsche stated in their owners manual on the Oil Viscosity Page }

From Minus 10 Deg Celsius ( 10 deg below freezing ) to Unlimited High ambient temps ( meaning 30 Deg + ) use 20w-50 , as a back up you can use a 15w-50 , but quite a lot of 15w-50 oils are low in ZDDP ( AW Package ) to meet strict  emission Protocols for other vehicle engines into this century , 20w-50 is pretty much a last century viscosity & hence allowed to have more ZDDP & so the slightly more viscosity 20w-50 than say a (  10w-40 which has less ZDDP, example only ) , the 20w-50 has a good ( high ) Oil Film Strength which is vital to last century high loaded flat tappet designed engines

Remember, the 928 engine was first designed ( on paper ) in the very very early 1970's at the same time as the NEW to the first world market( a new oil viscosity range) other than a mono grade( meaning a SAE 40 etc ) , and this new thing was the Multi Grade 20W-50  , I remember at the time thinking( mid 1970's) , wow this stuff ( 20w-50 ) is WAY too THIN , where as a late ( 2015 > engine oil ) like a 0w-30 , now that's thin , but that just goes to show how things have changed over the decades

But what has not changed is the the need to use the correct  oil viscosity for what the engine was designed for in the beginning & a deep last century Porsche engine , be it air cooled 911 or a 928 or a 944 must have a minimum oil viscosity for our climate of 15w-50 , but I always recommend a 20w-50 , like Porsche did when these were made

Bruce Buchanan
Buchanan Automotive

[Mike D'Silva]

Hi all

Looking to do an oil change on my S2 in the not too distant future and wanted to get some recommendations on oil. I know these cars need a good amount of ZDDP and the correct viscosity rating. With blends constantly changing and different offerings available in different countries I wanted to get some current aussie recommendations on products readily available here.

My car is primarily a street car and I don't tend to put many km's on (maybe 5k km every 12 months).

Some recommendations I've spotted on Rennlist and Pelican Parts:

Valvoline VR1 Racing Oil 20w50 (there seems to be a silver conventional bottle and a black synthetic version?)

https://www.autobarn.com.au/valvoline-vr1-racing-10w-40-oa01234

Nulon Street and Track oil 25w60 (is this appropriate for a street car?)

https://www.autobarn.com.au/nulon-25w-60-street-track-engine-motor-oil-st25w60-5

 

While we're on the topic, what oil is everyone running in their gearbox/diff? I understand the front engined cars use brass synchros. Recommendations welcome.  

Redline MT-90 75w90 GL-4?

https://www.redlineoil.com/product.aspx?pid=46

 

Justin, I like to use this.. lots of nice zinc.

http://www.supercheapauto.com.au/Product/Penrite-HPR-30-Engine-Oil-20W-60-5-Litre/1358?menuFrom=1021652

 

[TINGY]

I'm running Penrite HPR30 20w-60 in mine as well....though I've never come across a 20L drum of it, I always buy it when it's on sale at supershit or autobarn.

 

I'm running this oil as well, i change oil and filter every six months, but i do drive my cars so it's fairly cheap really.

[ANF]

Bruce, what engine oil would you recommend for a 89 928 S4 auto. Thanks. 

I like most others on here run Penrite HPR30 20w-60 in my 928.

 

 

 

[Peter M]

A question for the HPR30 users:  Did Porsche ever list 20w-60 in their owner manual viscosity charts?

[Pauly]

A question for the HPR30 users:  Did Porsche ever list 20w-60 in their owner manual viscosity charts?

It's 20w50 +10 It's just a marketing thing penrite do. 

[TINGY]

A question for the HPR30 users:  Did Porsche ever list 20w-60 in their owner manual viscosity charts?

I knew it!

[ANF]

It's 20w50 +10 It's just a marketing thing penrite do. 

http://www.penriteoil.com.au/assets/tech_pdfs/0What is EXTRA 10 - NOV 2014.pdf

[KGB]

Just do what Bruce says.

[Timm]

I'm running this oil as well, i change oil and filter every six months, but i do drive my cars so it's fairly cheap really.

Yes good point. Often people concentrate too much on what brand or whatever of oil to buy, but it is just as, if not more important to change it on time. Personally I dump mine out after every track day or two, so it pretty much always has fresh oil in it. Cheap insurance and your engine loves you for it.

[944s2cab]

Another one running HPR30

[Peter M]

So I take it that Porsche didn't ever specify 20w-60. 

So why don't you guys use HPR40 or HPR50 rather than HPR30 in your street cars?

I'm interested in your reasoning.

[Timm]

So I take it that Porsche didn't ever specify 20w-60. 

So why don't you guys use HPR40 or HPR50 rather than HPR30 in your street cars?

I'm interested in your reasoning.

Because they are too thick. I think at some point, the benefits of having the extra shear strength from a slightly thicker oil, are outweighed by the negatives caused by the thicker oil being too slow to get through the engine during a cold start. 20w-60 seems to be a good compromise between too thick, and too thin...to put it basically. I imagine there's a lot more too it then that...but I'll leave that to the oil scientists ;-)

[TINGY]

So I take it that Porsche didn't ever specify 20w-60. 

So why don't you guys use HPR40 or HPR50 rather than HPR30 in your street cars?

I'm interested in your reasoning.

NFI really, it needs oil i put it in, simples

I read Bruce's thread on oil once and he made a lot of sense to me so i picked an oil which i thought had everything that he mentioned in the thread.

I did read your thread on oil once as well Pete and i have the attention span of a gnat, i must go and see that therapist again.......

[OzJustin]

Thanks very much for all the responses guys. Ok it sounds like Penrite HPR30 20w60 seems by far the most popular option for engine oil. Will give that a try.

Despite being a mineral oil I gather changing every 12 months is fine given my low km's each year (no track time)?

Any more owner feedback on gearbox oil?

If keeping it in the family, the Penrite Trans Gear 75w90 GL5 looks like a good option.

[Philbee]

For 911/993:

Well, I have a 3.6 in my 911 and I've been trying to work out what to top my baby up with.... Read a few threads, etc... And being non- techie,it gets confusing, especially when there's different opinions. So, I rang a trusty mechanic, he said LIQUIMOLY RACE TECH 10-60. And then he added, Porsche only recommend Mobil 1 cos they're contracted to... Most Indy p-car joints use this. 

Well, that my 2c FWIW.

[T-Man]

 

For 911/993:

Well, I have a 3.6 in my 911 and I've been trying to work out what to top my baby up with.... Read a few threads, etc... And being non- techie,it gets confusing, especially when there's different opinions. So, I rang a trusty mechanic, he said LIQUIMOLY RACE TECH 10-60. And then he added, Porsche only recommend Mobil 1 cos they're contracted to... Most Indy p-car joints use this. 

Well, that my 2c FWIW.

Ive been running Mobil 1 V-Twin 20W50 for three years now. 

Plenty of zinc and lots of support on the 993 forums where everyone is an expert!?

 

[Peter M]

Because they are too thick. I think at some point, the benefits of having the extra shear strength from a slightly thicker oil, are outweighed by the negatives caused by the thicker oil being too slow to get through the engine during a cold start. 20w-60 seems to be a good compromise between too thick, and too thin...to put it basically. I imagine there's a lot more too it then that...but I'll leave that to the oil scientists ;-)

Thanks for your response Timm.

This begs the question: If Porsche don't even specify the need for a 20w-60 in their viscosity tables, surely that infers that HPR30 is just as unsuitable as the HPR40 and HPR50?

(I'm basing this assertion on two assumptions:

1. Porsche knows best.
2. Your car is primarily street driven and therefore the Porsche recommended viscosity grades are appropriate.)

 

I agree that this is a huge and often unfathomable subject but think we should be able to came up with some reliable and safe "rules of thumb" that are based on some sort defendable logic that guide us to good oil selection in all situations.

The comment regarding the expectation that shear strength increases with increased viscosity is interesting.  Do you know that there is no guarantee that the Xw-60 grade oil you buy has any greater high temperature shear strength than a 15w-40 oil?  http://www.viscopedia.com/viscosity-tables/substances/sae-viscosity-grades/

 

 

 

 

 

 

 

[Philbee]

Ive been running Mobil 1 V-Twin 20W50 for three years now. 

Plenty of zinc and lots of support on the 993 forums where everyone is an expert!?

 

I hope it's cheaper cos LIQUIMOLY is plenty of pesos per litre! I called autobarn... $105 for 5L ....ouch!