jimbo3

A couple of questions for the group:

-If one drives 1500 miles a year, how often should synthetic engine oil be changed?
-Assuming 1500 miles/year, would it be OK to skip changing the secondary filter on every other oil change?

TIA!

Cactus

I plan on a change around November each year and changing both filters. I have about 2500-3000 miles on my oil now and it looks almost brand new so once a year is probably overkill. I want to see what the experts here say.

Slow Guy

I believe you're going to hear you should change it once a year at least. Oil in an engine develops acids that you don't want to leave in the motor longer than that.

Personally, I drive mine about 3-4k yr. and change the oil once a year. It's due now.

V

You are probably going to hear lots of different opinions on thisone. I, for one am not a professional and this is only my sebjective viewpoint. Are you going to change the oil yourself or are you having it done? Because I assume that the costy part of the oilchange is the labour, not the material.. So if you do it yourself, change everything once a year, even with your limited mileage. Its a cheap insurance for your car. If you can afford a Porsche, you can afford to change the oil and the filters once a year. I understand your concern and I would say that its "probably" not neccesary to change everything (even the oil) once a year but I'd do it anyway just to be safe. Even if I you pay for the labour (as I do). Treat your car well, it's worthy of it. Just my 2 cents.

Cactus

Do you do both filters also?

jimbo3

My thought was to change it myself after two years (3-4,000 miles) without changing the second filter as it's a PITA. Then, two years later, have the shop change the oil and BOTH filters.

I've read several articles which talk about changing oil TOO often, and changing a synthetic after 1500 miles might well qualify as too often. If I do the above plan, the oil and main filter gets changed every two years/4000 miles max while the secondary filter gets changed every four years/8000 miles max.

Yes, a 993 deserves quality care and I'm 100% in favor if doing that, but is a full, complete oil/filter change every 1500 to 2000 miles simply throwing $200 down a rat hole?

Kigiin

No help here, but I have the same question. For the past several years I change mine yearly, around November too, with only 3K miles or so on it.... seems like a waste but then again it has been a year.

Surely this great synthetic oil can last more than a year with only 3k miles on it?

Rob

FLYT993

I'm no expert, but I've never understood the logic of not changing the filters and the oil at each change. You just contaminate clean oil. I run HQ synthetic and change it every 5k. Robin changes his every 7500. My understanding is you change the oil at least 1X a year regardless of miles, or every 5k. However, you WILL find guys who change the oil every 10k, not many, but there are some.
Regardless of the miles, if you only change the oil 1X a year, $200 is money well spent, for the insurance and peace of mind. Remember these cars have THREE oil gauges. That's Porsche telling us, 'hey guys....the oil in these things is important!'

BTW Cactus, you have one of most beautiful GR 993's I've ever seen....stunning!

tbil

Neither filter is really that hard to replace, extra 10 minutes perhaps? I think of it as the dirtiest quart of oil in there, worth the extra time. The ~$20 bucks per filter buggs but these arn't Toyotas.

Cactus

Thanks Dan! I'm thinking the hardest part of the oil change would be getting the car up on stands and finding a container large enough to catch 11 or so quarts of oil. At least if I spill any it is still clean.....

matt777

If you really want to figure out how bad your oil is after a few thousand miles get a sampling container and take it to one of the oil analysis labs. Some of them charge as little as $20 and perhaps the lube shops will do it. I did this on my Saab when the dealer recommended 2000 mile change frequencies. The oil was fine after 4000 miles. I saved a lot of money on synthetic oil and filters over the last 5 years. There is an argument that opening up machinery frequently increases the probability of introducing contaminants which has to be a consideration although I couldn't say how significant.

bv shady

once a year both filters. only put on about 1500 miles or less yearly -Paul

goldcountryboy

I have always changed my oil more frequently than not. I always change both filters as they are not that hard to get to. I also like to check out whats going on under my car,spend about ten minutes just inspecting things.I just found out that I need new valve cover gaskets.

FLYT993

Indeed! Here's a tip...punch a small hole in the filter(s) before removing. This allows the oil in the filter to drain. Then, when you remove the filter, nary a drop spills.

bgiere

Take a sample and send it off for a used oil analysis...there are many labs available, I use Blackstone Labs....I have tested M1 from 1986 911 that was 3 years old...The oil had approx 20000 miles on it. The UOA came back and the oil was hardly affected at all...It is entirely different for each car and climate however. If you have a car that is started frequently and not run up to operating temperature that is bad news...Combustion creates moisture and that moisture will accumulate in the crankcase unless it is "burned off" in a warm engine. If that is what your car is put through, then yes I'd be a more frequent changer...If you drive your car a couple thousand miles in the summer and regulary run it for longer drives I'd be very surpised if the oil was contaminated enought to warrant dumping 10 quarts of oil and wasting time and money.