What kind of oil should I use?

sfierle · 07-17-2003, 04:15 PM

I have a '71 911, and the 32 year old owners manual says to use 30 weight oil. So that's what I have been using. What are you guys using? I should mention that I don't race, or drive it that much (I have a company car). I want to make sure my engine gets all the protection it needs to last a long time. Thanks in advance!

masraum · 07-17-2003, 04:20 PM

How hot does it get in Michigan. If the temps are regulaly in the upper 90's and you do much driving when it is that warm then you could use 20 50 or if you don't drive it hard you could go with a 10 40. If it's not that warm then you could likely just stick with the 10 40. You could also go with a synthetic. I don't subscribe to the "synthetic in old cars is bad" theory.

The new oil formulas are vastly improved over the old formulas, so just about anything that you use will be fine, but the multi-viscosity oils will probably protect better than the single viscosity oils.

jmohn · jmohn's Garage

Something really slippery!

Seriously, you'll get lots of opinions so take your pick. I'll tell you what I use: "Shell Rotella T 15-40". Whatever your final choice, I do agree with Masraum (Steve) in recommending a multi-viscosity oil.

Jerry M
'78 SC

Rot 911 · 07-17-2003, 04:47 PM

20w50 non synthetic

island911 · 07-17-2003, 04:58 PM

20w50 full synthetic . . .to maximize the protection.

ruf-porsche · ruf-porsche's Garage

Whatever is on sale at walmart. If you change your oil every 3000 miles who care about the brand. They all met SAE standards.

1982911sc · 07-17-2003, 05:30 PM

My mechanic on my 1969 912 swore by Castrol 20-50. I never had any problems, I don't think you need to waste the money on synthetic.

SteveF_911 · SteveF_911's Garage

Nothing but Mobil 1.......

But my engine has less than 2k mile on it...

afterburn 549 · 07-17-2003, 08:50 PM

please do not use 10-40 its very hard on camshafts and related parts.yhats not my opion but from some high oil engeneers of viscosity pt spread. 15 40 is a better choice. Just my opion.

Sonic dB · Sonic dB's Garage

I use Shell Rotella T, just to be different and cool. So far its running great and no white smoke either.

jrdavid68 · 07-17-2003, 10:31 PM

Six hours and no one has brought taste testing the oil yet??

MY83SC · 07-18-2003, 06:31 AM

I have been using Castrol 20/50. Any opinons on the new "High Mileage" oils from Valvoline etc??? I think they may have too much detergent and cause oil leaks on high mileage 911s like synthetic tends to. When I rebuild I plan on going to 100% synthetic oil.

sfierle · 07-18-2003, 06:57 AM

My 911 has about 85,000 miles. I have also heard synthetic could be bad for it. Sounds like 15w 40 or 20w50 might be my best bet. Right? I change my oil once in the spring and once in the fall, although I will never hit 3000 miles between changes.

ruf-porsche · ruf-porsche's Garage

Quote:

Originally posted by sfierle
My 911 has about 85,000 miles. I have also heard synthetic could be bad for it. Sounds like 15w 40 or 20w50 might be my best bet. Right? I change my oil once in the spring and once in the fall, although I will never hit 3000 miles between changes.

If you change the oil in the fall and store the car during the winter
than when you change the oil in the spring it seems like you are tossing out oil that is almost brand new.

sfierle · 07-18-2003, 09:48 AM

It would be a little scary changing your oil once a year, wouldn't it? What do others do that store cars for the winter, and only drive 2500-3000 miles a year in warm weather.

SweetE · 07-18-2003, 10:11 AM

Mobile 1 15W50 syn in my 1971E.

It sits a lot like yours and is not driven as much as I would like. NO leaks.

This oil is designed to work with the earlier engine seals .

JTO · 07-18-2003, 12:13 PM

I just made the change from Castrol 20 W-50 to Mobil 1 15W-50, on the advice of a Porsche mechanic friend. I don't have a front cooler on my car (as of yet) and needed some relief from the higher running temperatures of summer. He said I should see lower temperatures with the synthetic. I can say that normally on my way home from work, driving about 70 mph and maybe 85 F air temp, I was seeing over 210 oil temp, maybe 220. After the change to Mobil 1, I took a long drive from Cottage Grove, OR to Arcata, CA and back. Oil temp, even in 90 F weather and a lot of fast and agressive driving, never got over about 210 F. That is about a 10 degree improvement, maybe more. So, I think I have switched to Mobil 1 15 W-50. I still need an oil cooler in front, just not so urgently.

Troy

PS. No oil leaks with the Mobil 1!

91C2wrencher · 91C2wrencher's Garage

sfierle, That's basically what I do, in the spring, as soon as the weather warms up for good, in goes the the Mobil 1 -15/50 and a new filter. In the fall after the temp drops for good, in goes the Mobil 1 10/40 and maybe a new filter maybe not. I rarely put more than 2-3 or 4000 thousand miles in a year. Yeah, I could use something cheaper but why? If I ain't got an extra $60 for oil once a year I should get a cheaper car. FWIW my mechanic has commented on how clean the inside of valve covers were last time he was in for an adjustment. Don't forget the Techron!

GSpreeman · GSpreeman's Garage

Castrol 20/50.

stormcrow · stormcrow's Garage

I like the Shell Rotella also because of its qualities. It is engineered for diesel engines.

This was the e-mail I received when I wrote Shell about using Rotella in my P-car

Steve -

Thanks for the opportunity to respond to your inquiry, and thanks for your interest in Shell ROTELLA T Multigrade.

ROTELLA T SAE 15W-40 is a universal oil, meeting API Service Categories CI-4 and SL (CI-4 for diesel engines, and SL for gasoline engines). Where the engine manufacturer recommends either one (or both) of these Service Categories, or earlier categories, ROTELLA T can be a good choice.

Some passenger car engine manufacturers also recommend oil meeting requirements represented by the API Certification Mark (API Starburst). ROTELLA T does not qualify for the API Starburst. If the Starburst applies, it would be to recent model Porches - it would not apply to your 1978 model.

Consideration should also be given to recommended SAE Viscosity Grade. For fuel economy purposes and very cold temperature performance, passenger car engine manufacturers usually recommend lower viscosity grade oils than SAE
15W-40. Again, low viscosity grade oils are usually only specified for late model gasoline engines.

The more robust performance of ROTELLA T compared to current passenger car oils makes ROTELLA T an excellent choice, specially for earlier model Porches. Better extreme pressure wear control and better deposit control are pluses for ROTELLA T.

Peter Van Benthuysen

Tel: +01 281 544 8253
Email: Peter.VanBenthuysen@shell.com
Internet: http://www.shell.com

Steve

"A Porsche does more then just go fast in a straight line"