[c627627]

Originally Posted by Bobnova

In short, oil changes are cheap, cars are expensive. Which would you rather buy more of?

You know about this more than most of us do. Much like an average person can't really argue with us on overclocking topics, it's difficult to argue car stuff with someone as knowledgeable as you.


We don't do 3K oil changes because - for some of us - $20 is real money. You care correct that they are cheap in comparison to car replacement cost. But day to day budget issues forces people to think they are not cheap because people have no $$.


The oil change frequency should not be taken to an extreme in the other direction but we don't do 3K because people we respect tell us. NPR's car talk is a well respected national car show. It is against Jiffy Lube's business interest to say this - yet they did:

OilChange1.pngOilChange2.png



EDIT: If you ask a dentist, how often should you floss, and he says after *every* single meal, is he wrong?

That's why it's hard to argue against what mechanics say here ↓ but realistically.... it's hard for us non-mechanics to ignore the other aspects of this question.

[Bobnova]

The car-talk quote needs the rest of the quote. 5k oil changes beat the hell out of 7k, for instance.
Many cars from the 80s and 90s have booklet maintenance stating 7.5k! It's obscene.
I personally am less than impressed with the car talk folks, the show is pre-recorded and scripted along with being more comedy than fact. That doesn't mean they don't know what they're talking about, I'm just less than impressed.
Environmental cost wise, the used oil is all recycled anyway here in cali. The recycling companies are getting set up to pay us for it according to the driver that picks up our used oil.

Jiffylube I have no idea, my guess would be that they were forced into it by the built in (dubious quality, IMO) oil change computer in some modern cars. I doubt people were interested in listening to 3k changes when they have an oil life percentage on their dash board saying otherwise, regardless of how long the engine will actually last if they follow that percentage.

Consumer reports... I don't really have anything to say there, it's a nice statement, though really rather short on content. I certainly cannot recommend following the manual having seen quite personally what that got people in the 80s and 90s with the long duration changes. It got them out of the manufacturer warranty without issue, but for people that planned to keep their cars longer it was less than ideal!



I think a disclaimer is worthwhile too, it is my opinion that the environmental cost of manufacturing a new car far exceeds any amount of environmental impact from maintenance. As such it is my duty as a mechanic to make every car last as long as possible. That means better maintenance than "enough". Think water loop cleaning at 6mo rather than 1-2y.
For people that do the buy new, drive 3-5 years and sell routine oil changes are essentially useless.
For the people who support that first group by buying their old cars, oil changes are a lot more important. They'd best hope the first people changed their oil, too!
For the next group down who support group 2 by buying their used cars (it all trickles down, heh) oil changes (and the history of oil changes...) are critical.

My nice new snazzy car is the 1989 prelude, it's old enough to drink alcohol now. The 76 volvo was my prior car.
The other volvo is my mother's car, while the integra is my father's.
I think you can see the trend now


I suppose a last disclaimer clarification would be good too:
As an independent mechanic my data is based on cars that are 5-7 years old at the newest (arguably newer data on oil changes is useless, it takes time to kill a motor with bad oil changes), the most recent crop of cars may well be able to go further, but we don't know yet. Also of course, my data is outdated as the average experience is 12 years ago on cars that were 10-14 years old at the time. In brief, my counter is that average car build quality has been declining since ~1997.
Given the changes I've seen to how cars are being made and their designed life..... I still strongly recommend 3k oil changes. As far as I can tell honda has bought into the american way (be great for the first owner, who cares after that) rather than the japanese way of the longest lifespan possible.
Toyota as well, thought not as much.





I thought I was done, but I'm going to add one more data point:
Every car that I have seen launch a rod through the side of the motor has not gotten 3k oil changes. As with any rule there is an exception: A 1991 toyota 4x4 that went through a "puddle" and hydrolocked the #4 cylinder.
Now this is a combination of things I think, one is that longer than 3k changes = oil burning (IMO).
The other is that none of these people checked their oil, so it was only getting topped up when it was changed. It doesn't take a whole lot of oil burning per mile to use up a fatal amount of oil in 7.5k miles.


EDIT:
If you want to be really accurate in your changes you can look at the oil itself.
If it is clean looking and translucent-transparent, it's fine.
If it's darker and/or more opaque, it is time (or past time) to change it.
That gets you away from mileage, which will always be an approximation and general rule at best.

[JCLW]

The only true way of determining your ideal oil change interval is to participate in an oil analysis program.

A lot of people in the US seem to use: http://www.blackstone-labs.com/ but I've never had any dealings with them. There is probably a local lab near you as well. Ask at a truck place. Or a Cat dealer.

If oil analysis is too much money/time/hassle then stick with the manufacturers recommedations. Manufacturers tend to be conservative in their recommendations in order to protect themselves.

You can get a rough idea by the clarity of the oil but like most things, the things you can't see are the things that get you.

Most modern cars will automaticaly calculate oil change intervals based on time, distance, fuel burned, engine load, and temperature. My Honda comes up every 8k~10k kms (5k~6k miles) depending on how I drive it and the time of year.

I do rotors every 2nd set of pads.

You will be able to visually check the pads when you rotate your tires or swap summer/winter tires twice a year.

[Niku-Sama]

i change the oil in my dodge stratus every 3kmi because much longer than that it starts to not hold pressure as well and throws the oil light on any way for low pressure, change oil, dont see it again till roughly 3k/mi

theres a bit of a problem with the 2.7l motor in it though. manual says every 6kmi for light duty service, light duty is not arround town dricing its, start the car, go and mantain the same speed and rpm for a long period car, stop the car and shut the engine off. no start stop start stop. and if your city driving the hell out of it the motor wears the oil down pretty quick in this car. there was even a TSB about the revised oil change intervals and an explaination about light and heavy duty intervals.

so with it being changed every 3k/mi i dont have sludge which alot of other people are having a problem with in this piticular car.

same thing with my 1979 280zx, every 3k, but its an older car

[ps2cho]

Oil changes and engine longevity are inversely related. The shorter the oil interval, the longer the engine life, excluding doing something stupid such as every 500mi. That's about it.

1988 300TE...I've done oil changes every 3-4k for last 70k and my valvetrain is like its brand new. If an old engine like mine can do it, these new roller-everything engines have NO reason not to ever be squeaky clean.

3-5k changes 7-10k synthetic with maybe a filter change in between unless its an extended type filter such as fleece...

[madhatter256]

I feel like I'm at bobistheoilguy forums...

Before deciding on going beyond 3k oil changes on a 10 year old car because mass-media articles say so, then by all means do a used oil analysis. It will tell you (if you paid for the right analysis) what the "life" of that oil is and from that determine how many more miles/months you can go by.

The general consensus is: modern conventional/cheap oil should be changed 3-4k miles. Synthetics (even cheap ones) can last beyond 4k miles.

But it all depends on many factors, such as engine health, driving habits, history of oil the car has gone through, etc.

And by all means, buy a quality oil filter... no orange cans.

They say if you can't spell the word brakes for your vehicle properly, then you shouldn't work on the brakes in your car....

[Bobnova]

Synthetic oil is another pet peave of mine.
Namely, most of what is marketed as synthetic is still refined dinosaurs.
The SAE (under pressure from someone, I'm sure) changed the definition of "synthetic" from what it initially was (ester based) to include highly refined dinojuice.

Now highly refined dinos are definitely going to last longer than normal dinos, but they have nowhere near the heat and pressure resistance of ester based stuff.
They are, however, far, far, far, far, far, far, far cheaper to manufacture.

[madhatter256]

Yeah, that's true. Rumorville on BITOG forums is that Mobil1 synthetic isn't what it used to be. Is it related to the definition change, who knows?

Only "synthetic" I've used was Quaker State UD for my 2012 Accent, which is currently in it. $20 for decent "synthetic" oil is a bargain coupled with a PureOne filter. I'm currently beyond the 3k oil mark for this current oil change and so far, the car still runs smooth, but will get changed by this weekend since it's a brand new car...

[Bobnova]

Mobil1 is one of the dinos, sadly.
That'd be a large part of why that old commercial with the frying pans in the freezer and oven disappeared. Dino oil, any dino oil, can't do extreme temps nearly as well as synthetic.

[madhatter256]

Originally Posted by Bobnova

Mobil1 is one of the dinos, sadly.
That'd be a large part of why that old commercial with the frying pans in the freezer and oven disappeared. Dino oil, any dino oil, can't do extreme temps nearly as well as synthetic.

True, but that is only applicable if you either race your car or live and commute through death valley during the time the sun is closest to earth.... So, changing the definition to include highly refined dino oil made economic sense.

You'd be surprised that oils in europe are meant to last a lot longer in cars, even though some cars there apparently use the same engine the American counterparts use.

[mxer657]

Oil Changes every 2k-5k miles depending on the car. If it's the sports car, every 2k. If it's the daily driver and is something like a flat 4, or a v6 then every 5k. Other than that, tires, brake pads, and top off all the lubicrants.

[BenF]

I tend to change my oil pretty early, usually between 3k and 4k miles. I have a bit of a heavy foot and enjoy spirited driving so I figured I should change it earlier rather than later (its cheap and doesn't take long either so there really isn't a downside). I change my brakes when they need to be done (wear indicators starting to make noise, rotors wearing unevenly, brake fluid every couple years). I typically like to change my transmission and differential fluid between 50k and 75k. I change suspension components when they start feeling worn out. Change tires when they are getting bald. Basically, besides things like oil, brake fluid, and tranny fluid, the maintenance intervals really depend on how you drive and how different things wear.