Dennis_said

Hello guys I searched moderately and mainly ran into posts about whether or not the 997 is a good daily driver vs daily driving oil changes.

was hoping for your advice. My 09 c2s has almost 51k I bought it at 47k from the dealer. I decided to check my oil levels in traffic yesterday and it’s at the lowest block so I plan on topping off. No warning light but my pcm unit is actually at the dealership for a fix so I don’t know if the lack of pcm would mean no warning fires .

anyhow I see talks betweem 0w-40 vs 5w-40 oil ... is there a preference for daily driver with some
spirited high revving portions? Should I do the changes at 5k or 3-4 as I’m seeing some others doing? Anybody go past 5k?

Thanks all planning on topping off today so wondering if 0w or 5w is the way to go!! Tia everybody

Fahrer

Always change the oil at least once per year. I think every 5K miles is quite adequate. There are many opinions about which oil they use but Mobil1 0W-40 is fine ( recommended by Porsche). I suppose if you live in a warmer part of the country, 5W-40 is fine as well. I have a 2008 C2S with about 30K miles. I change the oil once per year which is about every 3K miles for me. Many folks swear by special polyol ester based synthetics but I have my doubts about the compatibility with elastomeric seals and gaskets ( excessive seal swell) so I stick with the polyalphaolefin based lube ( Mobil1). My car uses little to no oil and no evidence of scoring issues.

I am sure that many will disagree with my view.

ADias

If your daily commute has some stop and go, change oil every 3k miles. Do not overfill - best to keep oil 1 or 2 bars below the top,

996AE

Funny how weve gone from Mobile 15k mi oil change "factory" to every 3k.

I dont disagree that every 6k or 12 months whichever comes first is a good idea.

But 3k miles?

Get a black stone report on your next change and start documenting. It will tell you facts vs lots of bench racing opinions on oil threads.

ADias

It all depends on the miles... Stop-and-go, and especially stop-and-go cold in the AM, more frequent oil changes has always been advised...

kdu

If you live in warmer climate, go Motul 5W-40. Recently switched over from Mobil 1 (i believe is no longer porsche A40 certified) to Motul, I can tell the engine likes it more.

140.6er

I’ve been a Mobile 1 0w40 for many many years with no issues. I may start using Motul 5w40 in summer though.

Wayne Smith

I'm at 120K miles using Mobil One 0W40 every 5K miles (since I acquired stewardship at 35K miles).

My daily commute was 30 miles one way. Now I'm retired and only hitting the office once a week so my miles aren't getting higher as quickly.

As for oil changes ... 7.5 quarts out and 7.5 quarts back in at every change. No top offs in between.

You'll find some who drain more and fill more, but I prefer running low so my quantities are lower.

In fact, I run on the bottom bar. This allows for thermal expansion and minimizes risk to the AOS. I burn 0 oil. Maybe running low has multiple advantages.

I would strongly advise against topping off!!!

cwheeler

Thermal expansion is not worth factoring in. Unless you are one that fills to the very tippy top.

If you poured oil in at 70* and measured while the oil was 250*, the expansion at MOST is a .5 quart. Which is one bar on our electronic measuring. But we aren't even allowed to measure at peak temp, so we wouldn't even see it at the highest theoretical expansion. And because our oil checker was designed to be read cold, I would bet thermal expansion is factored in.

Don't fill to the top, shoot for the middle. It lessens the chance of aeration and in theory, gives you a quart or more of expansion space.

Cw

Wayne Smith

On the 997.2 you have to be hot to measure. This is different than the 997.1.

Bottom reading to top reading on the 997.2 is about one quart.

While you don't drain 10 quarts during an oil change that's because you can't get all the oil out. Assume you have 9 to 10 quarts of oil in total.

Figure the thermal coefficient of oil at 0.00039 per degree F and allow for temperatures to 250 (I routinely see 275 on summer days playing in mountain passes).

Thermal expansion in this case can be a bit over a half quart or up to two plus marks.

Realize that you can't measure between the marks. When you read the bottom mark you may only need a teaspoon to reach the next mark. Jumping two plus marks could be over filled.

It isn't really this bad since on 997.2 cars you measure when hot at say 175F. Then 275F is only a 100F delta so your expansion is actually a bit under a half quart. On 997.1 cars where oil measurements are done cold thermal expansion plays a bigger role.

It is always best that the oil level be lower than higher to avoid multiple problems. Nobody wants to be over filled!!!

If you check out Hooked on Driving one of their prerequisites before taking your car onto the track is that the oil level is toward the low side.

The 9A1 motor of the 997.2 has great baffles in the oil pan and multiple scavenge pumps to drain the pan and fill the pseudo dry sump chamber. Foaming should not be a problem.

C4SDayton

I daily drive 36 miles a day. I had first oil change at well regarded Indy with M1. They recommended 7500mile or 1 year interval. I don’t know better than them what’s ok for my car so I’ll probably follow their recommendation for my driving.

996AE

15k to 3k mi is, even with stop and go traffic extreme.

Safe the world one un needed oil change at a time.

Get the oil report and stop guessing.

USMC_DS1

Attended a few flat 6 innovations m96/97 engine rebuild and performance classes over the years. As a result I've been implementing the following oil service protocol for my '08 C2S with 83K+ miles: oil service every 3k miles or 6 months(ideally) with Motul 5w40 followed by UOA - used oil analysis. This type of service interval minimizes the detrimental effects of acid build up. Allows for frequent inspections of the oil and oil filter(cut filter) for ferrous metals and/or other materials. Every 3rd/4th oil service the oil pan is dropped for inspection... thank you Tony Callas for this protocol. Many years ago I switched from Mobil 1 to Motul 8100 5w40. Noticed improved engine temps of ~8-10degF and higher oil pressure... good for Texas hill country runs in summer. There are better/different oil formulations than Motul. I've considered Gibbs but don't track so Motul was a relatively good and affordable oil formulation that was on the Porsche A40 approved oil list. Wanted an A40 approved oil while the car was still under CPO. It's also available via Amazon in 20L bulk shipment for less than $150. Each of these DIY oil service cost ~$110 for the oil, oil filter, plug washer, and UOA. I suppose that's fairly inexpensive maintenance for an m97 engine especially for the peace of mind... $220/yr.

vern1

You've got to be kidding

I predict that the common "wisdom" will soon be to change the oil every 3 months or 1k miles

Radmd74

What if one drives about 100 miles a month (semi-garage queen), at what interval do people recommend oil changes?

Obviously I won't hit 3k miles, so would it be about 1x year vs 6 months oil change interval as this post stated?

Thanks to all again.

Living in california so weather is modest most times of the year.