Consumer Reports says recommended 3000 mile oil change intervals are a bit of a scam - True or not?

Factual Questions
21

So change it with fresh running-in oil, there’s no added value in the swarf and grit. Imagine all the metal filings from the bearing bedding-in the bits of sand from the engine block mould floating around in the oil of your lovely new lump…

Random aside: Whatever happened to oil with colloidal graphite? This was historically recommended for running-in engines, as instead of the rough bearing surfaces shearing the little peaks off to form a polished-but-pitted surface the graphite would cause the little peaks to plastically deform into the pits, forming a nice smooth and uniform surface.

22

What is the proper timing if you don’t drive a lot?

I put, at most, 3000 miles per year on my car. My manual says 10K, but at the moment I do it once a year. I’ve heard 3 months, I’ve heard 6 months, I’ve heard go by mileage.

(In my case, the distance level of trips are very mixed, and it’s never been driven below freezing. Does get some grades steep enough to require downshifting.)

23

Hi Mr Magnet :slight_smile:
My late '02 C5 has 12,500 miles as the service interval. It gets done when the spirit moves me, anywhere between 2,500 an 7,000 miles. It has clocked up almost 140,000 and is barely run in compared to a lot of others. A guy near me has a taxi (he has a fleet of C5 taxis) that has done over 440,000 and still going strong.
They get serviced very frequently but run 17 hours a day.

24

As a bit of a car nut, and a veteran poster on another car site related to the LS1 GM motor, I can say that I would rather tell someone what I really think about their relatives, or what their spouse is doing while they are at work. Or argue religion or politics on the SDMB, than to get into another debate about which oil to use, or when to change it.

I will only say that I use Mobile 1. And I change it every time the seasons change. Winter, Spring, Summer, Fall. Which is way overkill.

The most important thing is that you DO change the oil regularly. The intervals aren’t as important as they are made to be.

25

Personally, I think it’s literally throwing money down the drain. CR tested this theory out on a fleet of NY cabs. This consisted of millions of tested miles. After 60,000 miles, the engines were torn down. There was no difference of wear between the engines having the 3,000 mile and 6,000 mile changes. There was also chemical analysis done with the oil. They also weighed the bearings and other parts before and after to check for wear. Here is that article.

FWIW, I’ve pretty much been going with about 4,500-5,500 mile oil changes on my 4 cylinder Ford Ranger I bought new in Oct’ of 1990. It now has 195,000 miles on it. I still doubt it burns oil, no smoke coming out of tailpipe or any blow-by, but does leak a bit.

26

My dad used this stuff-once! It was marketed by AMOCO-and it ruined his engine (clogged the oil passages).

27

Look at your damn owner’s manual! Do what it recommends. Mine says every 6000 miles in stop and go driving. 7500 mile under most conditions.

Who are you going to trust: The people who built your car or the guy who makes money every time you change your oil?

28

Emphasis mine.

You change your air filter every 3000 miles? That seems like a lot unless you’re driving in the Sahara

29

That test really doesnt tell you much unless you happen to drive your car like they drove their cabs. That test may be harsher and it may not.

Like mentioned by others above, if something like the PCV valve or fuel injection or sumptin else quits working right, the oil can go to crap much quicker than it would have if that modern engine was running properly. And a short oil change interval could make the difference between running 1500 miles on just getting crappy oil and 4500 miles on downright crappy oil.

“Overly frequent” oil changes are like crappy insurance IMO. Not the best deal economically, but there is still some chance it will save your butt one day.

If I have a vehicle, I am likely to drive it a LONG time. If frequent oil changes get me a few more months before the engine starts to die, they have paid for themselves, or at least somewhat have. Even very slightly better mileage due to a less wornout engine will add up to signifcant savings over many years. Piece of mind is worth something as well. If something does blow up, I certainly won’t be wondering if infrequent oil changes contributed to the problem.

30

Cars in the United States, have a nifty little thing called an oil filter. They don’t have those in Europe? No wonder I could never find it on my old 1968 air-cooled Beetle…

31

I won’t be using that any time soon then. IIRC I got this info from the Oddhams 1947 motoring manual, which also recommends spraying the horsehair-stuffed upholstery with DDT.

Fair point about the oil filter, Balthisar. But the swarf and grit has to wend its way through the engine to get to the filter, plus a clogged filter will lower the oil pressure.

Nars Glinley, yeah changing an air filter every 3000 miles does seem excessive, but on my current car it makes a noticable difference, as at about this mark the power starts to drop off and the engine develops a bit of a dip in the torque curve that makes (stick-shift) gear changes a bit lumpy. A while back I moved over to cotton K&N air filters, so at least I don’t buy an new one, just clean, dry and re-oil the thing. They’re great, and will give a bit more power than a paper filter; with my feeble engine I need all the ponies I can get.

Cheers to Myglaren for the extra Citroenisation of the SMDB - that C6 will be yours one day.

A neighbour of mine had a lovely old Merc, with an oil pressure gauge, and he said there was a noticable drop in oil pressure after about 3000 miles from an oil change. Don’t know what oil he used, I’d expect better performance from something decent. Anyone here run a car with an oil pressure gauge?

32

Hmm, I’ve always heard it was a myth as well, and this thread has some useful info. For one, I rarely drive more than 10 miles. Also, when I do drive more than 10 miles on the highway, there is usually a lot of traffic (4 out of 5 times, dang Seattle area traffic).

I was supposed to get my 3,000 mile oil change 2 months ago, but I still have about 500-600 miles left to go and that might take me another month.

So what is the verdict on the time interval between changes?

33

Time is a much less important factor than mileage, but most important is the type of mileage. From your description of the type of driving you do, intervals of less than 3,000 miles might be appropriate. This is where going by the time might be helpful – if it takes 5 or 6 months to accumulate 3,000 miles because of only or mostly short trips, changing oil at the suggested time may actually be closer to a mileage suitable for that type of use.

For the most part, though, just sitting there doing nothing (car not driven) doesn’t really degrade the oil, and in that sense time is not much of a concern.

34

Who are you going to trust? The people who make money when you have to buy a new car, or the people who make money when you have to change your oil?

35

Speaking as a guy that used to work for the factory AND now manages a service department (where we sell oil changes) I will take the factory engineers word every time and twice on Sunday over what Iffy lube says about lube it or lose it.
The point you are missing is that if the existing cars dies an early death the percentage of people that will repurchase the same brand goes right in the toilet. All car companies want to retain customers they are easier to hang onto then it is to find new ones.

36

If you’ve seen how N.Y. cabdrivers operate, you wouldn’t doubt that their test involved conditions harsher than what most drivers experience.

*"Our test conditions were grueling, to say the least. The typical Big Apple cab is driven day and night, in traffic that is legendary for its perversity, by cabbies who are just as legendary for their driving abandon.

When the cabs aren’t on the go, they’re typically standing at curbside with the engine idling - far tougher on motor oil than highway driving. What’s more, the cabs accumulate lots of miles very quickly, making them ideal for our purposes. Big-city cabs don’t see many cold start-ups or long periods of high speed driving in extreme heat. But our test results relate to the most common type of severe service - stop-and-go city driving."*

Ideally, the question of how frequently to change your oil would be settled by evaluation of thousands of engines over long periods of time. I don’t know who’s going to finance such a study - it’s certainly not in the interest of the automotive oil makers to do it. Absent such a study, I’d go with what CR says. And our wallets and the environment will be better off.

I’m not about to trust claims from people based on their “personal experience”, even if they’re mechanics. Testimonials are inherently unreliable; even if you’ve seen a case of someone who developed engine trouble after they went 7K miles between oil changes, you probably don’t know exactly what went wrong or how the person drove.

37

I bought a brand new Corolla that I drove for 8 years and over 140K miles. I changed the oil after 4000 miles often 5k miles and never had engine problems. Bought another Corolla to replace it two years ago, same oil change interval and still no engine problems.

38

Oil-change threads and anecdotes. A classic SDMB mix.

An old girlfriend had a late 1980’s Mustang GT Convertible (not that the convertible part matters much in the oil-change-frequency discussion, but you never know, because someone might chime in with how convertibles should only use Mobile One at 5500-mile changes).

But I digress…

Daddy bought the hot girl the black Mustang GT (5.0 liter/litre V8 that was really closer to 4.9 liters/litres. It was listed at 230 HP, but Ford revised how they calculated HP and I believe 5.0 'Stangs were rated at a more honest 215 and a bunch of usable, tire-spinning torque. Ahhh… good times.)

She proceeded to drive it for 64,000 miles… and it would easily qualify as severe use.

The engine seized when it ran out of oil. She never took it for an oil change; never checked; never added oil, and pretty much did nothing more than fill up the tank for 64k miles of driving over three years.

They added oil and fired it up. That was the ‘repair’.

Finally, at 220k miles, the old Mustang, now in possession of a friend of a friend of a friend, and lovingly known as “Jules 'Stang from back in the day” gave up when it wasn’t worth fixing the transmission and a million other small problems.

The lesson?

I don’t know, but I have a hunch that most oil-related problems are really sludge issues on some newer cars (like numerous Toyotas from early 2000’s).

I change my oil every 5k and use synthetic because I can afford it, and sometimes I wake up and realize I have 8k miles on the same oil in my Infiniti G35. :slight_smile: With luck, I will push that puppy to 200k like the other cars. Oil-related engine problem? Never new someone that had one. Oh, 'cept for Jules, but don’t know if that really qualifies!

TRANS OIL: I also learned that many “OMG! Change your oil at 3k miles or your valve train will wear out” panicy people are also cut from the “Hey, you should never change your tranny fluid or it will leak and the tranny won’t shift right” mold.

Change the damn engine oil somewhere in the ballpark of what the manual recommends. But some of you never change your transmission fluid!

.

39

On the other hand, if they’re being run 24/7, that means there’s no cold starts, which is really where most of the wear occurs. That’s part of the reason why OTR semi-truck engines go millions of miles between overhauls-- because they put on hundreds and hundreds of miles between cold starts (and if they’re left idling at night, maybe thousands of miles).

40

Although not in any way indicative of automobiles, railroad locomotives are in the same class – long running times with no shut off – and their oil is not changed at all. The three hundred gallon or so crankcase is filled when the engine is placed into the locomotive and that’s that until it’s removed, torn down, and rebuilt after about 100,000 miles. A sample is drawn and analyzed after each run to make sure nothing untoward is happening, but barring something going wrong the oil is never changed out.