Recommended oil and gaz for a 1985 stock 911

[Nico911]

Hi guys.

Need your opinion : what's the best oil to use on a 100% stock 1985 Carrera... 20w50, 10w50, synthetic, mineral, ...
And what about the gas. I'm planning to use 91 octane.

Let me know what you guys think.

[GaryR]

Ohhh no.

[awhnry]

20w50 dino with 100% real gas 93 octane

[James Brown]

some specific oils are, uggggg,: brad penn, swepco, kendall and some of the oils that have enhanced ZDDP in them (like oil made for classic cars, new buzz words) but at least 1200 PPM ZDDP. that's about as short i can make it. oil weight is up to you, no mobil 1 20w50 V-twin synthetic oil @ $10/quart. unless...........Rotilla is my fave. from wall mart.



got to keep this discussion under 10 pages

[GaryR]

Mobil 1 20w50 V-Twin, full synthetic, high ZDDP, only about $10 a QT!

[SilberUrS6]

Oh, crap. Here it comes...

[Nico911]

Damn, did I just opened a can of worms... To make things worst, the previous owner told me he used 91 octane gas and 10w50 synthetic...

Should we stop this discussion here guys ??????

[Porchcar guy]

This topic has come up ad nauseum so the search engine is your GOD...bring a sack lunch and a six pack...sit back and enjoy !

[SilberUrS6]

Originally Posted by Porchcar guy

This topic has come up ad nauseum so the search engine is your GOD...bring a sack lunch and a six pack...sit back and enjoy !

Troof.

The oil thread alone is something 91 pages, right? And lets not even talk about the transaxle oil. :P

[dshepp806]

WAY more than a six-pack....best get into distillery .......

On a personal note, I use 20W50 Brad Penn (although I drop to 15W40 in the Winter-(YES: I get to drive in the Winter around here!),..and it certainly has to do with Zinc and Phosphorous levels,..not to mention resultant (frequent) oil analysis.

Sorry,..I'm a fan of the flat-tappet nature/concerns of our period engines,..and am a disciple of Z & P...that is, IN the oil=no additives). I've heard the arguments but could care less,..she gets fresh oil at 3K miles (and a fresh filter),..period.

Frequent oil changes?,..Yeap: we all have our "quirks"., eh?

BEST!

Doyle

[Tremelune]

The problem with oil threads is that there is no constantly-updated summary at the top that presents the distilled conclusions hashed out within. A moderated oil wiki would be better...

The replies above are pretty good for that...

[nineball]

valvoline vr1 racing oil, 20w50. goes on sale once a year at autozone for around $2.50/quart.

[wildcat077]

Mobil 1 15W50 synthetic is available at your local CDN Tire stores and it often goes on sale for $9.00 dollars a litre ...
If one store has no more left,there are plenty around that will stock it !
Valvoline VR1 is no longer available in Quebec for whatever reason ... i used to use
it in my RX7 way back and i liked it at the time ...

If you're bent on using Brad Penn,PM me and i'll tell you where you can purchase it in Laval !
As for gas,use Shell 91 octane as it doesn't contain Ethanol yet ... if you decide to play at the track eventually,there are two
gas stations near LCMT that sell 94 octane !

Cheers !
Phil

[Nico911]

Originally Posted by wildcat077

Mobil 1 15W50 synthetic is available at your local CDN Tire stores and it often goes on sale for $9.00 dollars a litre ...
If one store has no more left,there are plenty around that will stock it !
Valvoline VR1 is no longer available in Quebec for whatever reason ... i used to use
it in my RX7 way back and i liked it at the time ...

If you're bent on using Brad Penn,PM me and i'll tell you where you can purchase it in Laval !
As for gas,use Shell 91 octane as it doesn't contain Ethanol yet ... if you decide to play at the track eventually,there are two
gas stations near LCMT that sell 94 octane !

Cheers !
Phil

Thanks Phil. This is very helpful.

[BarryJB]

I also hate to even enter this can of lube I mean worms but I do have possibly relevant cautionary tale...

Got my then stock '85 3.2 Carrera in 1997 w/160k. Had it thoroughly inspected - no valve guide work ever done, case split, anything. A year later, on advice of the great wrench finally found - 3rd time lucky, switched to Mobil 1 15W-50. There was a bit a galling on the cam, minor stuff, at that time, about 170k.

I only ever used Mobil 1 through the entire next 160k - engine had over 1/3 million miles on it, still no valve work or case split... all the head studs good, I thought it would last forever! Sure, 'twas was getting a little tired up hills, but not dead by any means, and used same pint of M-1 per tankful of gas of of spirited driving (read - redline most gears most days whenever possible) although true M-1 will find some way to leak from a 3.2, A/C worked, even hot days NEVER saw it go over 3rd mark (one just above 9 0'clock position) on temp gauge (250F)... the cam galling never changed, obviously, anyway. Rarely even past 9 0'clock (220F). Usually on first mark past bottom, 194F.

Car's always had more oil changes than suggested, even with the M-1 (plus it changes itself every 30-40 tanks of gas!)

Pump gas - CA Chevron 91 whenever possible, Shell equiv. when not. Techron!

Then... early Fall 2011, after reading all the lube threads here and on the advice of another utterly respected p-car wrench, I switched to Brad Penn... noticed it was running a tad hotter (needle-width sort of thing) after the oil change... month later, drove up to Laguna Seca for RR IV... close to arrival, shocked to notice engine had overheated - touching red - at speed on freeway (A/C never on) and a new intermittent slight rattle as I arrived at the perimeter road... oil level & pressure fine... still drove 500 miles back with no change in the ghastly noise (which was inconsistently apparent)... later, after 3.6 conversion (after all now I had an "excuse"), guy that bought my 3.2 mill said just one set of MB shells had burned, crank & rod OK...

Soooo.... while Mobil 1 has been worrying over years re changing & (un)listed ZDDP levels, etc, one thing is for sure - the 3.2 ran cooler on it than with the Brad Penn. I cannot say for sure the Brad Penn did in my 340k 3.2, but it was definitely a suspicious coincidence.

Now with the '95 3.6 engine, I am so relieved to have no worries about using only Motul 8100 X-Cess 5w40... oops, I hear dissent in the distance (but far behind me

Cheers y'all!
Barry

[HarryD]

Originally Posted by SilberUrS6

Troof.

The oil thread alone is something 91 pages, right? And lets not even talk about the transaxle oil. :P

Ya mean this one? Ultimate Motor Oil Thread or Why we hate CJ4/SM oils

But if you don't want to wade through it, try the Cliff Notes version:

It used to be true that "oil is oil". But be aware that motor oils have changed and not for the better.

A bit of history:

Prior to the mid 90s most cars on the road had flat tappets to actuate thier valves. It turns out there is a huge amount of pressure on the tappet/cam surface when it is actuated. This effect was discovered in the '50's (I may have the wrong decade but you get the picture) and a minor outfit called SAE noticed that cams were wearing out very quickly.

SAE paid some PhD's to do some research. They published lots of research papers and found out about these high pressures. They also found that a Zinc/Phosphorus additive known as ZDDP would provide protection to these parts at a resaonable cost. Gosh those guys were smart!

The SAE folks spoke with the API folks and asked if they could require ZDDP added to their required oil formulations to increase the service life of these critical components. Much to the pleasure of SAE, API agreed and based on the PhD recommendations, required about 1200 ppm of Zinc (Zn) and Phosphorus (P) added to oil formulations so the oil maker can get his product API certified.

This worked great but then in the 90's car makers went to more expensive Roller tappets which offered the advantage of lower reciprocating losses in the engine (i.e. better gas mileage). The use of roller tappets became standard in cars in the mid-90's.

In the early 2000's, the USEPA (for what ever reason) became concerned that the Zinc and Phosphurus in the oil would partially exit the engine via the tail pipe. This is a big deal since these two elements tend to kill the catalytic converters and, in theory diminish their service life. As a result EPA wanted to reduce the Zinc and Phosphorus in motor oils.

Fortunately (for EPA), car makers had already gone to roller tappets. Again the PhD's went to work. The clever PhD's found that the roller tappets do not exert the high pressures that flat tappets do. They did some more reaserch and found that for car with Roller Tappets, you could safely reduce ZDDP to a much lower level with no adverse impact on cam service life.

This change was codified in the API SM/CJ4 (and newer) oil standards. And while some formulations are permitted to have higher Zn and P, the cost of ZDDP relative to base motor oil is much higher and if the oil maker wants to save some money (i.e. increase profit or lower price) he merely needs to reduce the use of this relatively expensive additive and still claim conformance to API requirements.

Older engines (pre-mid 90's) STILL need high levels (around 1200 ppm plus correct level of detergents) of Zinc (Zn) and Phosphorus (P) to protect cams and other high pressure surfaces.

Use 20W-50 or 15W-40 oil. Brands frequently sugggested here, in no particular order, include:

Brad Penn 20W-50
Valvoline VR-1 20W-50
Kendall GT 20W-50
SWEPCO 15W-40
Joe Gibbs
Royal Purple
Redline
Motorcycle Oils

There are others as well.

[Marc Bixen]

Oil: slippery
Gas: flammable

[James Brown]

a good test would be to have 5 identical engines with fresh rebuilds and each has different oil in them and drive 100,000 miles and tear them down. but we still would use our loyal brand, whatever the results. or use that industry standard wear test-o-meter. i think someone has.

[nineball]

Originally Posted by James Brown

a good test would be to have 5 identical engines with fresh rebuilds and each has different oil in them and drive 100,000 miles and tear them down. but we still would use our loyal brand, whatever the results. or use that industry standard wear test-o-meter. i think someone has.

i'll volunteer to drive one the the test 911 cars for 100k.

[wildcat077]

Oooooh s**t .... here we go with a new oil debate again ... lol

Cheers!
Phil