How many miles on your oil before you change?

[aigel]

I sent an oil sample to Blackstone Labs. They compared it to the average oil sample in their database for the 993 / 3.6. Turns out that the average life on the oil samples they have in their database is only 2000 miles! Are people pulling samples on oil without changing it or are they service fanatics? Don't they drive more than 2k a year? On average, on your synthetic oils in your 3.6, at what mileage do you change your oil?

George

[kurquhart]

I change my oil at least every 500 miles, but it is a dedicated race car. I have heard of many racers that have their oil analzed, so perhaps they are making the average mileage appear so low.

[Don Settergren]

I always change my oil at intervals of 2500m as it is easy to figure out on the odometer...

[bigchillcar]

i just switched to mobil 1 15w-50...supposed to be a once a year or 15k mile oil. used to use dino castrol 20w50 in the summer and 10w40 in winter. i might put 5-6k a year on my car.

[Spud]

I change my oil twice a year, car is driven on the track more miles than the street, certainly less than 2k per year total.

[gamma]

Once a year, a good year for me is 3-4k miles. Kevin

[colo964]

Used to do it every 5000 miles when it was my daily driver (50,000 to 180,000 miles all Mobil 1 15W-50). Then at 195,000 (Jan 06); it's just approaching 210,000 when I'll do my next one.

It's not the oil that wears out, it's the additives. If the manf. says the additives are good for 3k, 6k, or 15k miles, chances are in todays world that they are.

On my Cat G3612 Generator Engines ($1.5M each) we schedule oil changes at 5000 hours (+350 gallons). Every 1000 hours we change the filters and add a couple of gallons of Cat oil additive and send out spec samples for testing.

If your using a quality filter and doing mostly freeway miles the oil won't have a problem meeting its rating. If stop and go, short trips where the oil doesn't get up to temp and stay there long enough to gas off condensation, etc, change more frequently. Always drain and cut open filter and examine filter media for debris

The drain plug has a magnet on it, I also run a 1/2 x 3 inch magnet in the oil filter on all my engines. The magnets pull the most damaging debris out of the oil before it recirculates and causes more damage. It has always warned me of a developing problem before major breakdown. Easy to check magnets prior to a long trip. I get the magnets at a Farm Feed Store, they're called Cow magnets.

Back to oil, it really depends on how you use the car, use that to figure out a reasonalbe maintenance schedule, or follow the owners manual, modify from there to fit your paticular driving style.

Later, Don

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[Black Ice]

I decided to do 10K miles because Porsche says 15K, I believe the oil folks and the change centers are out to get us with these 3K intervals, 993s hold friggin 11 quarts of oil (!), and I drive more than 40 miles each way to work every day.

I've had a Toyota Camry and a Honda Prelude that each went to more than 185K before I sold them (still running) and I put in Mobil 1 with 10-15K change intervals.