I use fully synthetic 5W-30 in my 1997 4.6. I change it every 3K miles.I have been told by more than a few people that fully synthetic oil was designed to go 6K miles between changes,that is why it costs so much more than non-syn motor oil. FACT or FRICTION?? (ha ha)

 

Synthetic motor oil is indeed capable of going further between changes. Your oil change interval depends on many things including your climate, whether you drive on short hops without a chance for the engine to totally warm up and other things.

Unless you do run short hops like 10 miles or less and then the engine totally cools off before you start it again, then 3K mile oil change intervals may indeed be too frequently.

All that said, oil is cheap, even expensive synthetic oil is cheap as compared to the cost of an engine. Engines are USUALLY even more expensive because most people replace engines by buying a whole new vehicle, which makes the engine cost from $15K on up.

If you are not running short hops then a 3K oil change interval will work quite well with dino oil. In fact there are many who think that changing oil more often with dino oil will give longer engine life because you are replenishing the additives more frequently and you are draining out the microscopic particulate more often. The microscopic particulate is what is responsible for timing chain wear.

Good luck,
Doc

 

Personally if you are comfortable changing it at 3000, then change it. I change mine once a month whether it needs it or not (usually at about 4000 on my work truck). I use a semi-synthetic. My concern has never been the oil, but the filter.

Another thing to look at is the cost (not really a factor). If it cost you $15 per oil change and you keep the vehicle for 150000miles, it will cost about $750 lifetime to change the oil at 3000 mile intervals. At 6000 mile intervals it will cost $375. So in roughly 5 years you will only save $375 ($75/year, $6.25/month). Not enough savings in my mind to change to the longer intervals if you have any doupts whatsoever.

 

My 01 uses Motorcraft Semi-synthetic 5w20 and the owners manual recommends every 6000 miles in normal conditions.

 

The owners manual recommendations are based on lots of different things, not the least important being that each manufacturer wants to make their car look like the least expensive to maintain.

For the average Joe that trades cars every few years and rarely sees 100,000 miles on his odometer, and doen't experience really off the wall conditions, 6,000 miles will get the job done.

If you're not the average Joe and run your vehicle several hundred thousand miles as I do, frequent oil changes are a way of life and the pay off is hundreds of thousands of miles.

Have a great day,
Doc

 

I do change mine every 3000 miles or so. I was just quoting the manual. It stays pretty clean, and at 46,600 miles, I have had no problems yet

 

I get grief for not changing more often. 10K or 12K mile changes, oil from dinosaurs like Ford intended. This one's at 183K and does burn a quart in 10K miles. Never even had the valve covers off. I chalk it up to (1) paved roads, (2) good oil additives these days, (3) tight engines that don't soot up with blowby, and finally (4) good luck. I'll bet until oil changes in the 15K to 20K mile range, you couldn't correlate engine life with oil change intervals.

I'm sure that you could 20 or 30 years ago. I lived on a gravel road, oil and engines were pretty primitive. Oil change equalled engine life. I don't think so today. In the '70s I worked for an oil analysis shop. Their clients were mostly heavy equipment and over the road rigs. Even in the dust of construction, with micron oil filters and regular analysis companies were changing 1000 or even 2000 hours, which would be 50,000 to 100,000 miles. The owner had a little Toyota station wagon, I'm guessing a '77 or '78 model (the really bad years for cars) with a micron filter. He added an additive package at 100,000 miles. It had only burned 2 quarts in 100,000 miles. When I left it had something like 130,000 miles on it with oil he changed when he put the filter on it at 500 miles.

I know, my Dad doesn't believe in it either but his first cars didn't even have oil filters. I'm not advocating, just saying I have had consistent good luck with longer than recommended oil change intervals. My average vehicle life is close to 200K and I've only had 1 smoker, a '66 Dodge Dart.

 

cantrma,

I'm pretty sure that there is something else that you left out of your list of reasons. I would be willing to bet that you don't drive this vehicle on short hops.

If you drive your vehicle at least 15 miles (give or take depending on driving conditions) or so every time you start it up, you are boiling out the moisture and acids rather than letting them build up in the oil. This is more important than the other reasons you stated.

If you drove a lot of short hops, your engine would have been wasted years ago.

This is all a perfect example of an OCI that matches your own needs and driving habits. Although I personally would never stretch an oil change that far even though I never do a hop shorter than 20 miles, it can work if everything is right. You obviously don't start it up, throw it in gear and mash the throttle to the floor all within the same second.

It also is likely that you don't drain your oil from a cold engine. Draining the oil hot will take out the contaminants much better because they are churned up in the oil.

For 90% of the motoring public, however, don't try what cantrma does if you are looking for long engine life.

Have a great day,
Doc

 

It's cheaper to change the oil every 3000 miles then to change the engine or any other parts that may fail, it's pretty much a fail safe program. My dealership recomends every 3000 over the manuel, but like LxMan1 said in NORMAL driving conditions." What's normal "

 

Doc,

I only live 1.5 miles from work. BUT, I drive it over 30 minutes at a time almost every day. And I drive it over 3 hours each way almost every weekend. So to your point, the water and acids are vaporized and get swept out through the PCV. And yes, I have always driven a lot, that makes a big difference.

One thing I grew out of is driving hard. I'm 48 and in the last 10 years or so, I've only had maybe 5 of my 60 or so speeding tickets. Not coincidentally, I picked up mild pinging in mid cruise. On this truck, only 50K miles ago or so, I was screwing around and the next time I had pinging, I thought hmmm, it's been a while since I noticed that. Over a few months of experimenting, I found that getting on the truck hard, just a few minutes, keeps it from pinging.

All that to say that when I drove hard and accellerated hard, I still got twice the miles out of an engine than average. They never wore out and 2 exceptions never needed internal engine work. If you drive it a lot (your original point), don't abuse it but drive it enough to keep it blown out, and (my point) don't drive on dirt or gravel, these things will last a long time.

Bottom line, I agree with you.

 

If you are changing oil every 3k in anything you are wasting your time and money.

LXguy is right, 6k is the right time to do it. I change mine about then.

3k is something that Jiffy Lube made up to get you in there twice as often, its bogus.

Can you backup your 3k claim with an oil analysis? I think not, the oil is still good and there aren't enough insolubules in it to warrant a change.

With a full synthetic oil, you can go 10k no problem. I would spin a new filter on it half way through, and top it off with fresh oil.

JH

 

I have over 40K now with successful 5K mi oil changes (MC 5w-20 & MC filter) since day one. All backed up with UOA's posted on the oil forum.
I fit into the extreme usage category acording to the manual. Except for the dusty conditions. My van is allways loaded and allways idling. I can take the key out while it is running, so when I stop I allways leave it running.
My wife's Jeep gets 7500 mi changes with Mobil1 all backed up with successful UOA's.

 

I think that there are some posters here who believe that "one size fits all." There is no one oil change interval that will work for all conditions.

Some people drive short hops, others drive it 50 miles without stopping every time they start it, still others drive in dusty conditions and on and on and.............

You just can't say that 3,000 miles is the perfect interval for everybody. By the same token you can't say that 6,000 miles is the perfect interval for everyone.

If you are going to err it should be on the side of changing it too often. Oil is cheap, vehicles and engines are expensive.

Have a great day,
Doc