AO

After reading the Used Oil Analyses by John here on the list, I became a believer that the old 3-5k mile rule of thumb was a bunch of B.S. Since I only put a few thousand miles on in a year, I've decided to change the oil each spring and save a few dollars. BTW, I've been using Castrol GTX 10W-40 with good results.

On my new Honda, the factory says to change every 10K. I figure once a year on that will be fine too.

Beth

Once a year for the black car - not even 3k a year on it. The green car, even though it's a daily driver, never leaves Napa so not a lot of mileage. Probably once a year on that one too. Both get Mobil 1

marton

once a year for me too.
I do about 6K miles per year. When i use it I usually blast it so it gets plenty of fresh oil between changes - thinking about it - why do I change it - it gets at least 6 litres of fresh oil between changes. BTW, if I keep it below circa 5K rpm it does not use any oil...
but a few laps of the Ring is good for 1 or 2 litres of fresh oil

Richard S

For the 928, once a year, Mobile 1, before the ORR season.

For the Toyota Tacoma....every 10,000 miles with Mobile 1. (which is about every 3 1/2 months)

My wife has her Honda serviced at the dealer...they should read their own manuals...manual recommends 7,500 miles, but the shop of course puts 3,000 miles on the sticker. Which I guess is a good thing, because my wife always forgets and by the time she reads the sticker for the 100th time it is around 7,500 miles anyway.

Rich

Beth

I'm just curious - why do all those oil-change-quick places tell you change at 3,000 miles? I assume so they can do more oil changes and make more money, but do people really listen to them?

Jim bailey - 928 International

Yes Beth all that money spent advertising has many people convinced that they NEED to ignore the auto makers recommendations and change oil too frequently. It amounts to consumer FRAUD as far as I am concerned and wastes our limited oil resources and consumers money! Jiffy lube has a special "club" for those who do the 3,000 service and the fine print of the windshield sticker states that to be part of the club you should change at the 3,000 mi interval . I rather wish I had started a class action suit prior to the recent change in California law.....there was millions to be made.....

FlyingDog

It's funny listening to people talking about how they've never had a problem with 3000 mile oil changes. They often get hostile if you tell them they're wasting money and oil by doing more than the manufacturer recommends.

My old SAAB had a recommended 7000 mile interval. It usually got changed at 5000-10000, once or twice 12000+. It was running fine when a tree fell on it at 215,000 miles. I finally sold it for parts when the tree dents started rusting at 217,000. The engine got some new seals and was reused.

deliriousga

Amen Mr. Jim!!

It's a great marketing ploy, especially with the average uninformed driver, but extremely wasteful of a non-renewable resource. If the oil change shops would be more honest with you I'd be more willing to take my cars to them. Instead they tell you every filter in the car needs to be changed when they don't need it. My wife still laughs because the first time she took one of our cars in for an oil change I told her "they will show you the air filter with a little dust on it and say you need a new air filter and wiper blades, but I just changed them last weekend." She laughed her butt off when the guy came in and did it. Now, 19 years later, our daughter takes her car in and the same thing.
Sorry, but I feel better now.

On the brighter side, I was glad when I took my wife's Boxster in to a local mechanic and he said he wouldn't change the oil until at least 10K since it wasn't called for until 15K and the Mahl filters are designed to last at least that long. He's gotten more business than all of the oil change places combined from us because of that.

mcv200

Mine is a daily driver and I'm looking foward to my first oil change since I bought my car in October 2004 at 3000 miles.

Thaddeus

Sorry dudes but I'm old school. I change it every 3K and I'm not wasting anything-- the oil gets remanufactured. I can tell the difference in the way the cars run.

If you drive in Minnesota at all, your use qualifies as 'severe duty'. My peace of mind is worth an extra 50 bucks a year per car.

oups59

Once a year. Late fall before storage.

Dave H.

928: twice a year (about every 3k), dino oil.

jetta: manual says 7500, so i went that interval once. the oil was way too dirty for me. so it's every 3k with Mobil 1.

Styln928

6,000 miles with mobil 1, 3000 miles with cheapo oil.

Doug Hillary

Hi,
there is ample scientific evidence that the Porsche Factory Engineers' original recommended Oil Change Interval (OCI) - one year or 20k kms (12k miles) is conservative and entirely satisfactory for most readers on this List. These limits were determined at the time using any of Porsche's Approved MINERAL oils. When using modern Porsche Approved synthetic lubricants they become even more conservative

The comments below apply to normal use for which the 928 was designed - like most of us experience

1 - The original oils that these limits were last established with were API quality rated SF/CD. These are long outdated having been superceded by MUCH better products. The SE(petrol rating) is now SM. The essential diesel rating CD is now CI-4Plus. Essentially the oils for our cars should be quality rated ACEA A3/B3 and endorsed "Porsche Approved". Oil in containers that say "Recommended for Porsche.." or "Meets API ??" or "Meets A3/B3" is not the right stuff! They may be API endorsed as >SM/>CF-4 too

2 - The Used Oil Analysis (UOA) reports from my engine using the following outdated synthetic oils;

a) Shell Helix Ultra 15w-50 Group 3 synthetic (SJ/CF) in for almost 14k kms and,
b) Delvac 1 5w-40 Group 5 synthetic (SJ/CI-4) in for almost 20k kms

showed that they were still serviceable after a full years operation and at the distances shown above. They could have both stayed in the engine for an estimated further one year without any problems - either short or long term

3 - In a petrol engine oil deteriorates (primarily) three ways;
a) from contamination (silicates in particular),
b) by losing the ability to control acid action (from combustion)
c) by changing viscosity up or down (the ACEA's limit is a 90% thickening at 40C and any thinning caused by shear or dilution - @ Porsche's test protocol equivalent to a mid range SAE30)
These can be monitored by UOAs

4 - An OEM (MANN) filter will easily last the full term of Porsche's OCI recommendations. They are so robust that they will easily last out to twice the Porsche recommendation. Filters usually fail due to the filtering media disintegrating or becoming detached. OEM filters are excellent and the Mobil 1 filter with a synthetic filtering media is great too

5 - Oil that is changed too frequently may well cause more wear. On-going research has shown that new oil can (and does) remove existing "plated out" Anti Wear (AW) additives and that greater wear occurs in the first 2-3k after an oil change

6 - Synthetic oils - especially Group 4 and 5 - are very good at leaving an AW barrier for start up. This is due to their excellent abilities in "polar attraction"

7 - I have studied many UOAs and I can attest Mobil 1 (which I do not use) has the ability to last at least the Manufacturer's OCI regardless of the type of engine it is in. Anybody changing M1 out at 3000k or six months is wasting money and a valuable resource

8 - There are no" magic" oils that will outlast and out perform the next one or make you engine last significantly longer. Buying an expensive "boutique" oil is usually just wasting money, despite all of the exotic claims as no conclusive data exists to prove them

9 - Techron will not influence the oil's content. I have monitored this is a number of cars via UOAs and it's use as recommended has zero impact on the oil

Regards
Doug