911Jetta

+1

I change mine every 2,5000-3,500 miles. (which = twice a year, usually in December and again in May)

Mezger

M1 5W-50 has a higher ZDDP level than very most other oils today.

https://mobiloil.com/~/media/amer/us...pecs-guide.pdf

greens

You can't get SH oil from 1992 anymore because it's inferior to what is being produced now. You make it sound like oil technology has gone backwards instead of forwards.

Certain grades of Mobil 1 are indeed inferior to others. You couldn't pay me to run their 10W30 in any vehicle. With that said however their 0W40 is literally the most spec'ed oil in the world. If I were using the vehicle as a daily I would run M1 0W40 without hesitation. If I were mixing in some track use I would use their 5W50. Both are far superior to any mineral 20W50 on the market.

Goughary

I usually don't answer back on posts like that. Only because we get into arguments easily it seems on threads...particularly about oil.

But in this case...

Keep in mind that the 0 10 20 and 30 40 50 etc are simply a measure of viscosity. Has nothing to do with quality or component makeup in the oil.

Has oil technology gone backwards? No. But, removing zinc and phosphorus, while ok for most components in a contemporary motor, was death to motors that were designed with any components where we had large flat metal surfaces under high heat and pressure, that needed lubrication between the parts. Ie, as an example, flat tappet cam motors. But this also extends to other parts as well...

Engine design changes made these components less necessary. Less necessary doesn't mean they aren't necessary. Most people keep their cars a few years and trade them in. Any oil on the market today will keep an engine running those few years. For me, I'd like my motor to go 20 years, 30 years, etc. 300k miles? If properly maintained, the bottom end of a 911 so go 200-300k miles and the top end should be right behind it with the exception of a valve job and guides...

If I were to use today's Mobil 1 0/40, this wouldn't be the case. But, after a fresh rebuild, using Mobil 1 would carry me a few years for sure.

With that. I'm ducking out of the oil discussion. I'll let Steve W or Colin or LN Engineering take it from here. My opinion is just my opinion. Use whatever oil you are comfortable with. There are plenty of places to send a motor out for rebuild.

Pendragon6

Thank you all for the great information.

I love this site!

onceover

I've been using Brad Penn but Jake Raby has had some bad things to say about it recently. Supposedly it was bought by another company and the formula changed.

If I can find Joe Gibbs locally thats what I'll be using. Otherwise I'll stick with BP

wallra

I'm running total classic. I don't want to put synethic in my motor that never had it. I've seen engines leak even worse If you switch them with a 123000 miles on it. This was factory fill back in the day. 20w-50

Goughary

Just going to toss this out there...synthetic oils don't make cars leak. What happens is they don't thicken up as much when cold. The viscosity remains more constant from cold to hot...so when the car is cold and the metals shrink, tolerances aren't as tight and you will be more likely to see some dripping. Our cars are particularly notorious for cold dripping, (or pouring) particularly the early non head gasket cars. Nothing really to worry about....

kos11-12

I can confirm Joe Gibbs xp6 15w20 is a fantastic oil ,
I use it on an engine for endurance,

crg53

You can get Joe Gibbs Driven DT 15W-50 at Lordco, but be prepared to pay a premium with the low CDN. Last year I paid $12 a bottle, this year $17.
I send a sample to Blackstone, and compared to the previous sample that was Brad Penn, the Joe Gibbs showed much better.

kos11-12

Yhea I was going to say very expensive , even more here in Europe, :-(

FormulaRX

I thought Mobil 1 15w50 zddp levels are 1300

FormulaRX

Check this chart out...

https://mobiloil.com/~/media/amer/us...pecs-guide.pdf

Mobil 1 synthetic 15w50 has 1,300 ppm of zddp. I use this in my 964 living in Southern California. So far so good. It's cheap, available at every Walmart, and as far as I can tell, a good appropriate oil for our cars. I'll stick with this.

Bill Verburg

The oil tempest came about because most modern cars are designed to use modern fuel economy(low viscosity) and emissions friendly(low ZDDP) oils w/ low ZDDP. Thes oils are too light and have too little ZDDP for our cars and should not be used in them. As w/ OBD standards this is a problem that arose due to political meddling in the engineering process.

Note that only the so called fuel economy oils were severely affected, these oils all have the API Starburst symbol on them, the oils that are less or not affected have the older API Doughnut symbol. These fuel economy oils are used in new cars to boost Cafe milage requirements. Their secondary benefit is increased emissions control system life by being cat friendly.

Note the weight and ZDDP levels from when our cars were new in red below and the current spec for M1 in blue

historical ZDDP levels can be informative ie before the current ZDDP tempest
M1 API SH 15w-50 circa '93-96 1095ppm P, 1427ppm Zn
M1 API SN/SM current spec 1200ppm P, 1300ppm Zn
M1 V twin API SJ 20w-50 1600 ppm P, 1700PPM Zn great break in oil!!

Notice that the current spec M1 15w-50 is as good(actually better than) as the original when our cars were new 1993-1996 SH spec???

break in oil needs high ZDDP in the 1400ppm + range, but above ~2000ppm long term wear problems arise
I've tried to find the ZDDP levels for other oils but only Brad Penn 20w-50 w/ ~1500ppm Zinc and ~1340-1400ppm Phosphorus meets the specs and has published data

the 993 Cup used SH rated 5w-40 M1 or 5W-40 M1 Rally.

If you can find current oils w/ that wt. and w/ the '93-96 spec for ZDDP go for it.

I've also been hearing good things about Chevron Delo 15w-50 but have no experiance w/ it and don't really know much about it.

The LN site is worth poking around in for additional oil info info

-Teme-

I use Castrol Edge 10W-60.