B Russ

Last oil change was almost 1 year ago but it only got 2500 daily driving miles on the M1. Does it really need to be changed?

ipse dixit

Yes

good2go

Why? Did the oil go bad?

B Russ

^^ My question exactly

TXGerman

I see plenty of people on RL that use oil analysis. Although I haven't used that on my 911 (yet?) I can say from experience in my professional life that oil analysis can be a very useful tool to determine when it is time for a fluid change. Only you can decide if the cost of performing that analysis is worth the effort vs proactively changing the oil vs leaving the oil in and going off of miles based interval instead of time based interval. I have long held the belief (belief does not necessarily equal science or proof) that time based maintenance intervals on our beloved Pcars is a conservative approach and, at times, doesn't necessarily mean it is the wrong or right answer.

For me, I recently performed a whole slew of time based maintenance that was "overdue". Since I am a fairly recent caretaker of this 911 I decided it was worth the money to perform these services and establish a baseline....for me. If I don't drive 7,500-10,000 miles in the next year, I will probably still change the oil at the 1 yr mark since it costs me less than $75 and that is "cheap insurance" for piece of mind. Just my $0.02

B Russ

I dont have the facilities to do the change my self at that location.

Porsche_nuts

Oil degrades with time regardless of miles.

Rich_Jenkins

Depends on how you view the near-religious debate on OCIs.

For me and my car? Absolutely, yes. An annual (at a minimum) oil and filter change will provide a new, unused filter element, eliminating oil flowing over any trapped particulate matter in the old one. New oil will replenish any oil additives which have been consumed to as-new levels. It will also restore the oil viscosity to the correct level, if it has dropped (as might happen if you are running a thinner oil (e.g. M1 0W-40) in a hot environment (e.g. Florida).)

XLR82XS

Oil & filter are less expensive than a replacement engine. (peace of mind)

visitador

It is not that expensive to change the oil according to time, right? Why not? This way you have a record of diligence in maintenance.

You maybe thinking of keeping your 991 forever. But in case you want to sell, it will be easier. A buyer may choose yours over another one with spotty maintenance records

asellus

Should you? Yes. Will your engine blow up if you don't? No.

If you're one of those people that starts their car every few weeks to idle it for a minute or whatever, you should absolutely change it (and also stop doing that, it's just terrible for the engine).

But even if you don't do that and let it properly sit, oil is hygroscopic and the crankcase is not a sealed system. The water content will rise as the oil sits. You have two options:
1) Run at operating temperature for ~30 minutes to cook out the water, however this fouls the oil with combustion byproduct and metals from internal engine wear.
2) Change the oil.

Either way the oil needs to be changed. One year is the generally accepted change interval.

good2go

How many engines do you know failed because the person did not change the oil yearly?

I would say he is doing more damage to his engine by only driving the car 2500 miles in a year. If I'm in town I drive the car daily if I'm out of town I call my son and ask him to take the car our so it gets driven. Keeps parts from drying out, and keeps fluids moving through the car.

It's a car, just like any car. put gas in it and drive it. The more times you fill the tank the better. enjoy your car.

ipse dixit

Engine oil has a shelf life.

That shelf life is even shorter when used inside an engine.

asellus

This is a gross oversimplification that's rooted mostly in truth.

That truth is what drives the remark of "should you, yes, will it blow up, no" above. The tiny bit of rust forming will cause pitting which will lead to increased wear which will lead to scoring and eventually catastrophic failure. Suppose the engine, perfectly maintained and not abused, will last 250k miles before needing a rebuild. With poor oil change habits? Might be 190k.

It's not the biggest deal, but it's a best-practice and recommended by the engineers who designed the engine and the oils for a reason.

Many if not most people on this subforum today will not be here in 5 years, they'll be in the 992 forum or whatever next model is called.

koala

FWIW, it's a 2-year drain interval in Europe.

I personally think that is insane. Change it once a year! I don't put a lot of miles on mine. This year I've done 4,500 km and I'll still be changing the oil before I put it away for the winter.