What is the longest oil change interval you have gone?

[Ctopher]

Originally Posted by stevej37

I read once that the mileage minder on Hondas factors in at least three different inputs for oil life.
As long as the oil meets the specs...it uses mileage, rpm's, and oil temp to show when the oil should be replaced.
I think changing it any sooner is a waste of money. (even though 10K seems too far)

I've also read this and when I bought my 2006 Civic Si I did a few early oil changes based on the maintenance minder (MM). I started with the first at 19xx miles, then 50% then around 0% and lastly 1k miles past the 0% MM. All samples were run on Castrol GTX 5W30 - plain old Dino oil. And for those wondering my commute was around 40miles round trip. And I would drive the crap out of the car, pretty much running into VTEC the first 3 gears and very often to the 8k redline. I did notice that the more VTEC the more oil she would drink. The 2014 sample was a normal run with nothing special. The 2018 was the new Castrol GTX UltraClean which had a higher TBN for a normal run. I even had Blackstone test a 2nd time as it was a surprise based on previous samples. So depending on quality of oil, type of engine and driver 5k should be easy on most engines or more. The exception would be for DI cars and especially turbo versions.



CTopher

[cabmandone]

I just found out I'll be going 10,000 miles because that's what Toyota recommends. That is unless I decide to change it myself before 10K. I need to find out if that will have any effect on warranty if I change it myself using synthetic oil. 10K just seems nuts.

[Scott Douglas]

That question has been asked a lot on the Honda forums. Consensus seems to be that they can't hold it against you as long as you use oil that meets the specs they require of oil.

[island911]

Originally Posted by cabmando

I just found out I'll be going 10,000 miles because that's what Toyota recommends. That is unless I decide to change it myself before 10K. I need to find out if that will have any effect on warranty if I change it myself using synthetic oil. 10K just seems nuts.

It's not nuts.

Testing has been done.

Consider that you have been conditioned to believe it's nuts.

I know, "conspiracy theory' right? I mean why would Jiffy-lube to Midas -and every sub-par mechanic in between- suggest you regularly spend more money with them?

[911 Rod]

It think delaying oil changes will come back to bite you years later at high mileage.
Which will be the next guy.

[island911]

Originally Posted by 911 Rod

It think delaying oil changes will come back to bite you years later at high mileage.
Which will be the next guy.

Sure, you can think that.

And you can think that if a car isn't waxed every week that it will will come back to bite you years later.

Engineering has come a long ways. People who don't understand that will cling to conservative positions of the past - when cars ran fuel rich (which would get past the rings) had crap oil and thermal management that was often sub par. (pyrolization of oils.)

[stevej37]

3K mile oil drained from my SC looks more than twice as dirty as 10K mile oil from my Honda Fit.

[911 Rod]

Originally Posted by island911

Sure, you can think that.

And you can think that if a car isn't waxed every week that it will will come back to bite you years later.

Engineering has come a long ways. People who don't understand that will cling to conservative positions of the past - when cars ran fuel rich (which would get past the rings) had crap oil and thermal management that was often sub par. (pyrolization of oils.)

So what is your theory? 20,000 miles or maybe never?

What does waxing have to do with an engine?

[island911]

Originally Posted by 911 Rod

So what is your theory? 20,000 miles or maybe never?

What's your theory on this?

[stevej37]

I just this am checked my Honda Fit for the oil change minder. It says I have 6100 miles since my last change and it is 50% of the way to needing the next change.

I normally do it at 20%. If I wait till it gets to zero..I'll have 12K miles on it.

[masraum]

Originally Posted by stevej37

3K mile oil drained from my SC looks more than twice as dirty as 10K mile oil from my Honda Fit.

When I was 16, I had a '65 Chevy with a (not stock) 350 from a junk yard that was probably a '72-74. Changing the oil always resulted in black dirty oil. At one point, I put in a new rear main seal which involved dropping the oil pan. While the oil pan was out, I thoroughly cleaned it. There was a thin layer of gunk in the pan. After that process, oil changes resulted in oil that was barely dirty at all and still mostly transparent.

Presumably, (and I'm not suggesting this) if you could thoroughly clean the bottom of your case, oil tank, engine mounted cooler and front mounted cooler (or loop), your oil would look pretty darn good every 3k miles.

[island911]

Oils have come a long ways.

Fuels, and fuel metering systems have come a long ways.

Engine materials and manufacturing have come a long ways.

[island911]

Originally Posted by stevej37

I just this am checked my Honda Fit for the oil change minder. It says I have 6100 miles since my last change and it is 50% of the way to needing the next change.

I normally do it at 20%. If I wait till it gets to zero..I'll have 12K miles on it.

Sounds right. And that has a relatively tiny oil system. (unlike a 911 carrying ~3 gallons)

Even my old 80's VW -I just saw the owners manual- it recommends oil changes at 7500. Those engines go hundreds of thousands of miles with ease, where corrosion is usually the downfall.

[911 Rod]

What about the lower compression turbo engines everyone is going to?

[GH85Carrera]

Originally Posted by MRM

Several years ago Consumer Reports did an article on what oils worked best and did a side study on how long to go between oil changes. They ran NYC taxi cabs with identical rebuilt engines and opened the engines after set distances. They found no meaningful difference between oil brand. They also tested whether the interval between changes made a difference. They ran some engines 3,500 miles, some 7,000 miles, and one 12,000 miles. There was little to no difference between the engines when they were opened and the internal wear compared.

I think this is the article I was thinking of. Consumer Reports:Truth Motor Oils- July 1996

My old Chevy 305 went 300,000 miles before the valve guides and piston rings were worn out to the point of excessive smoking.

And am sure if I had gone 50K miles on the oil change and then disassembled there would be little wear, but lot of sludge. The wear on engine parts at just 12K would be virtually undetectable even in bad conditions.

I keep my cars long term. The Elky I have had 30 years, the 911 just 26 years. Nether are for sale for any reasonable price. Oil is way cheaper than engine repair. And sludge never gets better, just worse. And sludge will causes lots of problems.

That 300K 305 had regular oil changes. When I pulled it out to put in the new 350, I took the 305 apart. There was almost no sludge at all.

[looneybin]

Ok, not a car, but I’ve had a Honda mower for 15 years, I’ve NEVER changed the oil in it.
When I check the level, it’s full, so I just start it and mow

[tabs]

Never my old porsche leaked so much it alwzys had fresh oil.