Oil Change Intervals
 

I used to change my oil religiously every 3K. back in 2003 I stopped and started doing it every 4-5 depending on how black the oil was.

The trucks I drive at work are all diesel and are on oil changes every 5K, but sometimes they go 10K or more if our mechanic is backed up, or too busy catching some Zs down in the garage. They say diesel engines are dirty and need oil changes more frequently, so I figured if our trucks are still going strong on that oil, then my gasoline car ought to be okay for a lot longer than 3K on the oil change.

just wondering what all of you guys do your oil changes at.

yeah i think the whole 3k oil change thing is a scam. The garages then get you in there and do their "courtesy check" and find a bunch of other crap to sell you while you are there. I used to work at firestone about 5 years ago. I did mostly tires and oil changes. Firestone are a bunch of crooks.

With 111k miles on my Prius, I have only changed the oil 8 times. Once at 1500 when I drained the original oil and replaced it with Mobil 1 0W-20. Next at 10k, 20k, 35k, 50k, 65k, 85k and 105k, each time with the Mobil 1. Each time I changed the oil it looked like it had barely been used so I streched it further the next time. I will change again at 125 or 130k depending on how it looks and smells.

I drive 35k miles per year, mostly on the interstate.

WOW that is a great bit of knowledge on the Mobile1 and the Prius which is supposed to run pretty clean because of its clean burn operating mode and preheat coolant. But you are still changing it a lot more than I will in my xB with Synlube - once so far and maybe in 2009 I will change the filter again. Presently at 2 years old I have 18,175 miles total with Synlube installed at 3700 miles after changing out the factory break in oil.

frequent oil changes are also good to sell maintenance programs and voiding warranties when you miss one or two. I recently heard of a Chevrolet dealership telling a truck owner that they weren't supposed to take the truck off the road;even though " off-road" was written on the side of the truck.( wheel barrings damaged by mud)

change my own 1 time/year,w/ a filter change half way. amsoil on ~12k miles.

I change my oil in my company car every 5,000km/3,100miles. This is a company policy, and they pay all the bills, so I don't complain. It does irk me that they force us to dump out perfectly good oil. Oh well...

On my own cars, I have practiced the "change it when I feel like it" method. I can count on one hand the number of oil changes I have done in my life. Never had a single problem with any of my cars either.

Now I am the owner of a TDI. Being a diesel, it has rather stringent requirements. I plan on doing a 10k oci, but I am going to get my oil tested as well. Really, the best advice is to just use a high quality synthetic, and have it tested at different intervals. This will tell you YOUR best time to change. Climate, driving style, odometer, terrain, engine manufacture quality, fuel source, and hundreds of other factors affect an oil change interval. Anyone that tells you a magic number is full of crap. Everyone has to find out for themselves when they would be best off changing their oil.

If you think that America is bad, over here in Japan the shops tell you to change it every 3,000 kilometers (funny how that is the same number as is used in the USA), or 3 months, whichever comes first!!! You could practically drink the stuff at that short of a service interval! AND, Turbos and diesels are recommended to change at 2,500 kilometers. Pure insanity... plus pure profits for the garages who follow this dishonest practice.

+1 It's very dependant on the engine, your driving, the terrain, temperature/time of year, condition of the engine, etc. I've heard of 1500mi w/ full synthetic (wish I had that much money) and the one I've heard with the most logic to back it up was 2-3x a year: once when the weather warms up, once when the weather cools off, more if you are particularly brutal to it. reason being the winter causes more wear/degredation of oil because of the cold-starts, blow-by from large cold engine tolerances, extended warm up period, etc. and the summer change (which is also usually 2x as long) is just that long of an interval.The other once I've heard is change it as you like and send in a sample to a testing facility, if it shows signs of wear and degredation, change it more frequently. if it looks like its in great shape, leave it in longer.
In my own car, I do around 3k +/- a lot because my rings are worn thus blowby crappifying the oil but my stem seals are bad so I leak oil and have to replace it (1 qt/1k miles). usually I just go till I pull the engine out for one reason or another (I like to tinker...) or it starts to smell burnt (take a whiff of the oily dipstick)

I never realized people leave the oil in so long. I'm going to start this practice, or at least go by the longest Honda recomended interval I see printed in the owners manual.

Next oil change I plan to switch to synthetic which I'll run for about a year.

the recomendations in owners manuals will varry from 3,000-7,500 for the same car, depending on how it's driven, as best as I can tell it basicly comes down to right around 120 hours, if you do mostly city driving and hit an average speed of 25mph, then 3000 miles is 120 hours, if you do highway driving at 65mph then it ends up being around 115 hours.
if I remember right, the twice a year oil change came from when you put lighter weight oil in in the winter, and heavy weight oil in in the summer.

Each engine is different. If you look at used oil analyses on BITOG, you'll see that oil change intervals for many modern engines can go 5,000+ miles. Engines are better and so are oils. Doing a UOA with a place like Dyson Analysis is a good way to learn what's happening in your engine. We do about 70% highway driving in our Accord 4 cyl, and our OCI is 6,000 miles +/- a few hundred. We're switching to a great oil made by Renewable Lubricants that is a combination of plant oils, mineral oils and additives that is producing great results.