3.2 Oil Weight - mineral vs synthetic

[healeykit]

Hello Everyone

My first question would be obvious if I had a manual (but I don't) - what oil weight goes in a 1987 carrera 3.2 engine?

My second question is more disputable - should I switch to synthetic or stay with traditional motor oil?

[DCinVA]

I use Mobil1 15W50, but you will hear many differing opinions here.

[GH85Carrera]

OK, go get something to drink, and you might need to pack a lunch. Sit down, relax and click on this link.

The thread below will take a few hours to read and you may want to scream. The information is overwhelming. You will learn more about oil than you ever wanted to know. An expression my dad uses is "I just asked for the time, I don't need you to tell me how to build a watch" may apply. All in all it is good information. Pelican Parts should sell t-shirts that say "I read the entire oil post and I survived"


Ultimate Motor Oil Thread or Why we hate CJ4/SM oils

[Robert Buchanan]

I'm not going to add to this four year running controversy...oil is oil and what was in the manual back in 84-89 still applies.
However...the Castrol High Mileage (green bottles) has what us 'mid eighties' guys need and has some ZDDP in there without breaking the bank. Your pocket book may indicate a more exotic oil...but changing the oil every 1500 miles has the same effect in keeping viscosity and cleanliness at a premium level.

I am in Houston (target for Gustav) and the blacktop gets to be 160 degrees pretty easy. My 86 911(74500mi) likes the 20-50 Castrol HM, the '88 DE 911(87770mi) likes it too and runs a few degrees cooler for some reason. Probably the rich mix for the track.

The Boxster (Barbie Car) likes the expensive stuff. Since the Queen drives that one, she gets what she likes...Mobil1, and we run 5-30 for a little more power. That one has only 40K on the clock. After 50K we plan to go to 20-50 M1.

After much head banging, my senses came back and I remembered what my Grandfather said once..." use a thicker oil in an older engine"..makes sense as tolerances open up. At our operating temps a heavier oil is of no concequance on performance. And helps the older bottom end to stay oiled.

BTW...as for A/C. I switched both of my 911's systems to R134. This was too easy. Drain the compressor, add 8oz of Castrol Ester A/c oil compatible with R134 directly into the compressor. Note, I did not change O rings.
GENTLY blow out the hoses as well with very dry air (you do have a drier, right?).
Add a new Keuhl Evaporator and drier(came with oil) for R134 and get to a good A/C guy to evac the system to near zero, and fill for the first time. I had a head pressure of 300# with the engine lid open initially. Dropped back to 225# with lid closed. My A/C guy (forty years experiene) said that we might add some oil in a year or two if the system leaks down in that time.

After one year, both still hold a good charge and the '86 will freeze your chessnuts off on the middle settings. Outside temps in the mid 90's....

911_pilot

[3.2 CAB]

I too use the Castrol GTX 20w-50w in my 84 3.2 I have not gone to the high mileage or "old age type oil" just the standard stuff. The engine has about 54,000 on the clock. Any vehicle that has a good bit of mileage on it, I would choose NOT to use synthetic oils, just dino, as the synthetics seem to make an older, dry, higher mileage engine start to leak at seals and such. If the engine was run since new on synthetic, I would run it, but if it has always used dino, I would not change it over due to the chance of starting a leaker. Good luck!! Tony.

[Dees 911]

I use 15-50 Mobil 1. My 82-SC doesn't drip or leak and I've got 130K miles. Previous owner recommended it and I see no reason to change.

[drl911]

'86 Carrera w/ 165,000 miles, Redline 10W-40 for 4 years with no hint of leaks.... (did I just jinx myself?). Changed every ~15,000 miles or so.

[carrue529]

I use Brad Penn 20-50, replace every 3~4k. I'm happy with it no leaks 255k miles with 45k on re-built motor

[richemj]

Originally Posted by carrue529

I use Brad Penn 20-50, replace every 3~4k. I'm happy with it no leaks 255k miles with 45k on re-built motor

+1 here. Vouch bigtime for Brad Penn (old-school Kendall)

[Robert Buchanan]

I agree regarding the synthetics...meaning to not use them in an older engine.
I had a '90 964 that was bone dry on GTX 20-50 and switched to Mobil 1. What a mistake. It took a month, but she would puddle after warming the engine. Not a lot mind you....but enough that I could not state.."a dry engine". It had all of the recalls fixed....the puddle would grow to a silver dollar size.

As per the usual feedback we each have our favorites. Most replys had a lot more miles than mine and everyone seems happy. That's how it's supposed to be! :-)

In my book...oil is a lot like saving a file on the computer. Save early, save often.
In the 3.2's...change early, change often.

911_pilot