Oil change frequency?

It's more better manufactured engines have tighter piston seals letting less water and, now cleaner, fuel into the the greatly improved oil.

Today's oil will last longer even in cars that originally called for a 3000 mile change interval.

GM and Honda already monitor engine speed, temperature, and load, plus ambient temperatures, to determine when to change the oil.

 

Yeah, I like that, better than a basic odo counter. Our 06 Civic Hybrid had the maintenance minder, and while Honda didn't really detail the variables, it hints with "engine operating conditions" and "engine revolutions":



For us, the 15% remaining warning would come on around 8500 kms. We did a fair amount of short trip driving, and: 15% is not 0%, but once that warning came up, I would change the oil, maybe a bit early, but that's me.

 

Well, servicing dealer here in Texas's sticker says 3 months/5,000 miles, so I've got 3 more oil changes before the 2 year limit.

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Seems this question comes up a lot. There is a thread on this question that is 5 miles long. Lots of opinions. Lots of logic. My answer? I'm old school. I change every 5k (filter also). My first change wasn't till the 10k mark, because I decided to try it. The oil was absolutely filthy! So, from that point on, its been at 5k and my oil still looks good when I change it. I recycle the oil where I buy it. And I don't mind doing it more that what is recommended. Bottom line, its a personal decision as to when to do it.

 

That's the underlying debate: use oil to near-exhaustion, or not so much. My take, oil in the engine is not fine, fine, fine, fine, then suddenly, at 10K miles: not fine. It goes off gradually, and I'd rather overdo the changes.

The one thing I do entertain (but have resisted, so far) with the 6 month interval (which is per spec in Canada, btw), is to do the oil filter only at every second oil change, per Honda. I sense I've opened another can-o-worms...

 

In a way, frequent oil changes are cheap insurance, even for those of us who can't/won't DIY. Much of the little driving I do is stop and start, and I can't always be the best Prius driver I can be.

I've had my Gen 4 18 months and I'm just about to hit 9,000 miles, mainly because I hate driving around here. I refuse to join the NASCAR demolition derby.

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Mendel made the point...oil and other lubricants don't just "all of the sudden" go bad. Just like a Prius does not just "all of a sudden" run out of oil.

 

How filthy the oil appears doesn't tell you if it is still doing its job.
Dirty oil is just as slippery as new oil.

When it comes to lubricating, the oil doesn't go bad. Over time in the engine, it tends to thicken, which only hurts efficiency.

The reason for oil changes is because there are additives that get used up. The main one that oil analysis looks at for determining time to change the oil is total base number for the acid neutralizers. It has nothing to do with lubricating and protecting the engine from wear. It just neutralizes the acids that form when water gets into oil that is in use. They can be viewed as fine, fine, fine, and then not fine, since as long as there is any left they keep the acid levels low enough to prevent corrosion.

I once changed the oil filter in the HHR about a week before doing the oil. After that week of driving, the black, dirty oil was most of the way to looking like new. The particles that cause the oil to look black are a source of that acid.

The price maybe cheap, but there is the cost of more used oil in the system.

 

I just love how Google empowers non-Mechanics to think they know more than real Mechanics.

 

In self defense, it prevented my Camry from having the engine oil sludging issue that Camrys of that vintage were prone to. I'm not a mechanic, and I don't play one on TV.

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No defense needed pilotgrrl...my comment was directed at those doing 180 your current track.

 

But have you ever stayed in a Holiday Inn Express?

 

The free ToyotaCare only covers every 10K miles or 1 year though. You will likely need to pay for the additional changes.

 

How many cars have you seen or heard of die an early death from issues of too long oil change intervals? How often have mechanics known more than the engineers calling for a set oil change interval?

I am not calling for oil changes beyond what is recommended here. I am pointing out why changing earlier in a modern car is a waste of resources.

If anything I have said is wrong, it should be easy to provide a counter.

The 4 cylinder, correct? The sludging was caused by a design flaw. To cut costs, Toyota reduced the number of coolant channels in the engine block. This lead to the oil getting hotter than it was meant too. The cost cutting likely also meant inadequate testing to check the design change for potential issues. If the manual was already calling for a full synthetic oil, more frequent oil changes are the only fix besides replacing the engine. If a synthetic wasn't called for, using it might allow normal intervals.

Barring design or manufacturing defects, oil should not be sludging in a properly running engine. It will happen eventually in the oil, when the particles that make it darker get too numerous, and overwhelm the detergents in the oil, but that isn't happening within the recommended oil change interval.

 

Trollbait how could I ever doubt your expertise.

I'm just some lowly, dirty, smelly, foul mouth career Mechanic that is responsible everyday for the lives of thousands of people in the air...so what do I know.

 

This thread is why they just made it back to my Ignore list.

 

I can't believe nobody has mentioned BobIsTheOilGuy.com by now.

 

Perhaps because Toyota has more inside knowledge of our vehicles.

 

True but Internet experts love to quote from it.

 

Actually, I never have. Most of my travels have been in Japan, and there aren't many of those there. I've stayed in a lot of "business hotels" like Toyoko Inn, which would be equivalent, but cheaper.

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