Oil Change - Mileage or Percentage?

[Ironhorse]

Wondering how others schedule an oil change in the GMT400 vehicles and newer. For a good number of years since I've been driving, I always changed at the 3,000 mile intervals while keeping an eye on the oil level. If it was below a half quart I added the needed oil in between the mileage intervals. Never let it get below the half quart level.

The 5.3 LS was the first engine I encountered that used an actual percentage countdown for scheduling an oil change. What if anything changed that the 3,000 mile interval would no longer be warranted? I do no hard driving, dusty road conditions or heavy load pulling of any sort is done. Normal in town driving and occasional trips to Wichita, about a 100 mile round trip to and from with running a few errands in and about Wichita. I use 5-W30 full synthetic and Wix filters in my '05 5.3 Tahoe.

What's your oil change standard in the 5.3 LS and newer engines?

[Just call me Sean]

I think to myself "man, it's been a while since I've changed my oil" then I might remember to actually do it six months later. The odometer doesn't work in my S10 or van, I'm sure they're due. Especially the van. Just did the 93, but I was changing the head gaskets so I pretty much had to. I don't think I have ever changed the oil in the 99, maybe I'll remember to do it six months from now. It has a pretty good leak though so the oil pretty much changes itself.

[franken]

Percentage of what?

[Palf70Step]

The reminder in my 02 was configured for about a 5000 mile oil change. Like you I did mine at around 3000 since I drive in dusty and sandy areas. The oil change reminder would pop up just at random time. I reset it and that was it. On my newer Nissian I do it about every 5 K since it is full synthetic. MY wife's Honda's reminder comes at around 9-10K. I probably do it at around 8-9K. For me it is not just about the miles, I look at time. I do all of mine at least by the above mileage or max of every 6 months. Since a lot of my driving is short hops and it's so humid there I feel that it's not run long enough to heat up and get the moisture content out of things.

[special-K]

Originally Posted by franken

Percentage of what?

Percentage of total capacity lost. A 1/2qt would be 1/12 (<fraction not percentage) of 6qts. I never heard of that, but I never had an LS powered vehicle. I go by the oil age/use, not the engine it's in. At least not a newer engine design used the same way the older ones were used. I always did 3,000 mile intervals but many of today's oils are good for up to 5,000. Amsoil claims changes not needed in big numbers of miles but I look at more than just the oil lasting. I look at the filter life and the best oil in the world suspends particles same as any, I'd think. My oil changes are about changing the filter. A vehicle that loses a lot of oil, in a way, is constantly changing it's own oil. I know it's not the same as changing 100% all at once. But the main thing is the age of the filter. I don't buy the change at percentage, unless I hear a damn good argument. It seems there is a general attitude coming along out there that says all that was is no good and needs replaced with what's new. Seems to be a millennial thing. It ain't my thing. No replacement for real life experience or the tried and true. I guess the proof is no longer in the puddin'? I think it's because millennials didn't get spanked

[Palf70Step]

I never thought of percentage that way. Like on my wife;s Honda, it is registered in percentage, but it is based on mileage not some other kinda magic stuff. Since most of my stuff is older if they have a change light it just pops up one day. I guess a lot of the reminders in the modern vehicles have a percentage countdown for your oil reminder.

[special-K]

I see that as an add reminder, not a change reminder. New engines can leak or burn oil, too. But why would a leaky or sick engine require more frequent changes, unless the engine is dying with particles increasing by the day? In that case a "change engine light" would be handy . You'll find out soon enough w/o a warning light, though

[Palf70Step]

A lot depends on who you listen to on oil and change frequency. When I was putting a lot of miles on (average 60-70K a year), I looked at type of driving, when and where I was driving, plus I looked/felt the oil when I was checking it. Just got use to a certain feel. Biggest thing for me for the shorter intervals besides dirt, is moisture. IF the engine is run for short little 10 mile or less intervals, the engine never gets hot enough to evaporate the moisture out of the engine. It's more of things I have learned over time and feel comfortable with. I was told at one time to just change the filter and top off the oil. I never liked that cause there was still stuff in the oil that you may not want there. As you mentioned engines "use" oil, either leaking or evaporating, so watching that is probably the most important to keep things at proper levels. Same way with weight of oil. Newer ones, like the LS and my 4 bangers have very small oil passages, so the older mentality of up the weight to say 20-50 might not be good. I sometimes think that the recommendation to increase the mileage is more about creating wear so you'll need to get new engine/vehicle sooner. Do what you feel is right and make s you comfortable with the care.

[Keith Seymore]

It's "percent life".

Oil life is a "time and temperature" phenomenon.

The sensors monitor and display the amount of time at a certain temperature level, number of start ups, cold weather usage, etc and use that information to project the total life expectancy of that oil change.

I don't normally say this but I'd trust the computer and change it based on the monitor, rather than accumulated mileage. It's doing what it was designed to do.

K

[Palf70Step]

Was not aware of that. Thank you Keith.

[LS short box]

My 20 Silverado goes by mileage? Right around 5000 miles the display says change engine soon. After awhile it will change engine oil. Oil wise whatever it says in the manual. I always run Mobil 1. Never had an issue. My drives are always longer than 10 miles so moisture isn't a problem.

[special-K]

Engine hours is a good idea. but need to install a meter to know. Miles has worked for me since I started driving in '71. I see no reason to change now. There is no line in the sand when it comes to oil change. It's a grey area no matter what method you use

[Ironhorse]

Thanks for all the replies and the related info provided. Am leaning towards going back to my 3,000 mile intervals. That would put me changing oil about twice a year since being retired I don't put near the mileage on that I used to while working. Again, don't do any pulling, no dusty roads being driven on. I always check oil at least every couple weeks while driving locally only for the most part. No long hi way miles driven for quite some time.

[biketopia]

The 3000 mile oil change, especially in the US market, came about directly from Jiffy Lube and their marketing of the 3 month 3000 mile oil change. Then, as oil's, fuel, and engine management improved those numbers started to get larger from an OE stand point. Like Keith said, the reminder in your vehicle is not actually reading the oil, it is using data and an algorithm from the last time it was re-set. It takes data from ignition cycles, engine temp, outside temp, engine load, etc to countdown that percentage. When DPF's were first placed on diesels in 08' you could be driving down the road watching your oil life in a Silverado and be in the 80% life left range, then a regen would happen and it would drop you 30-40%. The early trucks would inject fuel on the exhaust stroke to light off the DPF vs having the 9th injector, but the computer knew it would dilute the oil.

Extended oil changes are a double edged sward these days. Because of low tension rings most OE's use now to get to their fuel mileage numbers they carbon up easy, old dirty oil makes that happen faster, then you start burning oil, and it never gets better. In the US, the extended intervals of 8-12k+ are also marketing tools to "reduce" the the total cost of ownership and maintenance. I was looking up data on a trans flush for a Subaru the other day, the US owners manual says it's lifetime fluid don't change it. In Canada and elsewhere it says to change it every 30-50k...

I manage a fleet of over 500 assets for a local water utility and we run most of our trucks at a 5k oil change interval, except our big trucks and heavy idlers, those are done at 250 hours, or typically 2500 miles. Many fleets have started to do oil samples and find they were over servicing though. But to Tim's point, the filter get's changed regardless which is arguably the biggest part of the oil change.

[Tom]

My oil change interval is the same for all vehicles. 6k miles on synthetic, 3k on dino oil.

[MySons68C20]

My wife's 2018 Tahoe oil monitor is 7k between changes all hwy miles.

My 2017 Duramax is at 5k....mostly city miles.

[special-K]

I figure the computer is trying to duplicate what only the driver would know. Not that a whole lot of drivers have no idea what's going on, they just drive. Going by a lower than actually needed mileage interval assures no matter what the usage or conditions the oil is not being run longer than is healthy.

[Ol Blue K20]

I run Mobil 1 synthetic in the burb since that's what the original owner put in on the first oil change in 95. Thus I'm on a 5000 mil,e interval. It's the first big block I ever had that doesn't use oil. I ,carry a spare qt but it doesn't need it so far..

[Richard]

Big rigs with high oil capacity can change oil at 20k or more. It is common to have the oil tested instead of a change because of the high cost. Wonder what the oil test would show on a DD car at 3 or 5k? My wife's new and past few cars are (were) at 10-12k on indicated oil changes. Maybe I will send in a sample for testing at the next recommended oil change.

[OutlawDrifter]

5k miles on full synthetic with a Wix filter. Oil is "cheap".

If you don't drive the 5k miles per year, once a year.

My Z28 & '49 GMC both have LS powerplants and generally never make 2k miles per year, they both still get an annual oil change.

I'm a big fan of Castrol Edge.

The 454 powered Suburban gets a different flavor, Rotella T6 5w40.

[hatzie]

I usually change the oil on my T800 around 5,000 miles. It's always well before the oil monitor gets under 25% so I'm not running way past the oil life.
5,000 is one of those easy to remember numbers and it doesn't hurt anything to do it that often.

[Ironhorse]

Seeing as I don't do any long haul driving, pulling/towing and dusty road operating may give this last oil change the 5,000 mile / oil percentage option a shot and see which one shows up first. The 5,000 mile distance or "oil life percentage" .

Thanks for all the replies.

[Jeepwm69]

I do 5K intervals on the road cars. It's easy to remember when it's due because I change on every even 5K interval.

I do much less on my Jeeps and 83 GMC, because they aren't driven much.

Oil is cheap.

[GSP7]

Originally Posted by Jeepwm69

......................

Oil is cheap.

not anymore. nearly doubled in price ...............

[special-K]

I do 5,000 mile oil changes and that's a good time to rotate tires. I don't care what oil someone runs or how long it is advertised to last. I want my oil filter changed more often than some oils claim to last