Robin 993DX

Most car companies claim that they have "extended" synthetic oil in their engine which requires less maintenance. Just FWIW, it is all a marketing thing. Do not follow their recommended oil change schedule, I think the published maintenance schedule is more for "cost of ownership", comparison purpose. Not for the long life of your engine!!! I have seen plenty of Mercedes, and BMW engine taken apart with extended factory recommended oil change interval and they are in terrible shape!!!

grwoolf

Very interesting read from the Ferrari guy, especially the idea of going with a 0w30, 0w40, etc. to minimize startup wear. That seems to make good sense and I'm not sure I see a what the downside would be on a synthetic.

The entire article is generally from a standpoint of water cooled cars where the operating temprature is fairly consistent, but I think most of the concepts apply to an air/oil cooled engine also.

I guess there is still the debate of the zinc levels and valve guide wear, but the Mobil 0w40 sounds pretty good if you believe what this guy has to say.

matt777

True. My BMW has 14000 mile oil changes! It's interesting how infrequent the changes are when they are paying for it (free maintenance) I'm not sure I would want to own the vehicle deep into it's life cycle.

gr8330

Or every 12 months, which ever is less

Quadcammer

that was some good reading, but I do disagree with a few small parts.

particularly the expansion/contraction of engine parts. 2618 or 4032 aluminum pistons contract far more than the iron bores in most engines. This will result in a larger piston to wall clearance at start up.

Edward

Craig,
Thanks for the Word Doc!

Robin,
Thanks for the post. Talk about having done his homework!

Edward

Marco8

Funny I saved it as a word doc too, before seeing your post....oh well

NC TRACKRAT

Robin's excellent dissertation is good information but doesn't bring to light the latest concerns about the lack of sufficient ZDDP additives in the current SM-rated oils. Our older engines were designed with the assumption that the oil they specified would have these additive packages, which today they do not. While viscosities at start-up and at operating temperature are certainly factors, they're not the only parameters of concern. Given a choice of perhaps having to replace the catalytic converter due to using the additives or re-building the engine because the additives weren't in the oil, I'll take the cat every time!

CaptainGSR

I'll save that reading for a lonely winter night. Not Christmas day!

FlatSix911

Robin, great post.... thanks

Edward

Funny you mention the ZDDP. As I was mulling over (again) the lengthy (but compelling/interesting) dissertation, I was thinking of that very question that has been hashed and rehashed here at length: is there enough "protectvie zinc" et al. to "do the job" well? I kept waiting with bated breath for that to come up in the writing; it didn't.

That said, I am very interested in looking into 0w/40 synth (or something close, maybe a 5w/40-50 if there's one around) again, whereas before I had summarily dismissed it because of my SoCal climate. Maybe even for the Trackmeister as well which does see some seldom street use to keep her healthy.

What keeps coming back to the forefront of my mind is whether the benefit of a lower "cold weight" oil outweighs that of a better additives package, like one that includes more zddp, for example ...especially given the frequency of the oil changes in both my dailydriv 993 and track SC. I mean with oil changes at around 5K miles, and dramatically fewer miles with the T-meister, oil just doesn't "seem" like it has much of a chance to degrade when changed at this frequency. Hmmm. So that said, anyone else thinking likewise? Perhaps a good synth in 5/50 that doesn't kill cats?


Edward

zone5

If you're going to use synthetic oil and replace it every 5,000 miles or so, why use synthetic? It is supposed to last longer than that.

As of 2-3 years ago, Porsche has gone to recommending oil changes every two years, or 15,000 miles, whichever comes first. If you live in Alaska and leave your car outside in the winter, I can see changing it more frequently than that because the temperature extremes would "age" the oil. Otherwise, I don't see that time has that much of an effect -- the additives in synthetic break down based on wear from the moving parts of the engine, which correlates to miles driven, not sitting in the engine -- if it wasn't that way, we'd want to see freshness dates on the stuff we buy at retail, right?

I can't buy the argument that Porsche's oil change recommendations are based on cost of ownership. AFAIK, Porsche has never advertised their cars as desirable because they are cheap to own, and they have never provided full maintenance like BMW does. For Porsche to say to owners, "don't bring your car in as often, it doesn't need annual oil changes after all," -- what is the possible upside to that, other than telling the truth?

If you're only driving your car 4 or 5 thousand miles a year, I don't seen the point in annual changes.

For those of us who do own high mileage cars (I'm not one of them) I would love to hear about their oil change habits.

Regarding the worn valve guide/SAI issue, which is the engine wear subtype we all worry about, it would be interesting to hear Steve Weiner's viewpoint -- it seems like the wear some people are experiencing is all about how well their motor was manufactured at the factory and how their car was driven rather than how often they changed their oil......

dionz1

Awesome! I learned something today, and now I need a beer! Lets make that a light beer. Ill save myself for full bodied beer till later.

DanL993

Geez, didn't you hear me, MORE COWBELL!!