oil changes on newer cars

67newport

Old Man with a Hat
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with the cars today running synthetics oils and claims of longer oil change intervals 7500 miles and up do you still change yours at 3-4k? i do and 2 guys i work with says my thinking is 30 years ago they do theirs at 7500 miles witch i find very hard to do. no matter if the oil is full synthetic of conventional oil that oil is still dirty at 3-4k and to let it go to 7500 miles. i don't understand why they go that long and pump the dirty oil they their engines that long. the cars i have that i am talking about is my 16 accord 2.4l that i drive to work in the summer 0w20 and my winter car 08 civic 1.8l 5w/20 castrol in both. since they go 55 miles round trip i usually go to 4 thousand between changes. are they rite and my thinking old school and or do you think i am for trying to keep the engine clean in side?
 
It depends. I'm still a 5k change guy and that at the recommendation of my two best friends who are master technicians. The GDI engines today rely on good engine oil to do more than just lubricate rotating assemblies. When it breaks down, it affects injector timing as well. That's for my daily drivers.
My two friends and I started running Amsoil on our Duramax trucks a few years ago and did 20k each on the oil and filter for one cycle. Lab analysis showed the oil was still good after 20k. Although the results were good, we all decided that 7500-10k was good enough. We're not that cheap.
 
I run full synthetic in all my modern cars, 2010 Avenger, 2012 Ram and 2019 Scat Pack. I change the oil in my Avenger and Scat Pack every 3k and the Ram Cummins every 6k. Overkill? Probably but changing the oil too often never hurts. I've sold three cars that I bought new, a 96 Intrepid, 3.3L 160k, a 98 Ram 5.9L gas, 200k and a 2006 Charger 3.5L, I think it had about 100k, none of them burned a drop of oil and all ran perfect when I sold them. The dependability that the oil changes provide is worth the price of admission IMO.
 
Modern engine are cleaner and more efficient in every way. New there's no blow by, or cold start over fueling. The oils do still get dirty but it takes considerably longer. Synthetic oils keep there viscosity where conventionals thin out over time. Any Amsoil dealer will tell you to change the filter and add a quart every six months. (or so they used to) The new filter cleans the old oil and with the new quart it should be full. In the end it comes down to preference. I change all my cars at 3500 miles. I run a synthetic blend. I swear I can hear a change in the engine. My old cars get their oil changes once a year. Unless I go over 3500, coarse with gas as it is. That probably won't happen this year.
 
If you get the engine hot(20+min) almost every time you run it. The longer you can go. Short trips only I would still error on the early side, 3k.
My wife drives 45 min each way very little stop and go traffic, but not all open highway. I get hers changed at 5k.
 
As a former automatic transmission test engineer, I'll say this:

The OEMs know their products far better than we do and are designing/testing for a longer service life than 30 years ago.
I saw significant differences in wear of components when synthetic oil was used - if I saw a cleaned part (synth and conventional were different color) and knew the duty cycle it was run under I could tell you what oil it had used, it was that noticeable.

EFI has dramatically extended oil life.
GDI and some other things have tapered that a bit.
And some engines have sensitivity to oil breakdown that is cured by more viscosity (Hemi lifter tick comes to mind).

But overall, you can trust the OEM's recommendations. There's a lot of oil industry and OEMs experience there.

(sure, people can pull out specific exceptions to harp about, but it doesn't disprove the trend)
 
My wife's 11 Caliber has the oil monitoring system and it is usually around the 10-12K km's range when it calls for the oil to be changed. The look and smell of the oil coming out of the crankcase leads me to believe it was in there to long...but what do I know. ;) Car still runs good with no major issues so I'll just keep on doing it this way.

My old Cummins crewcab I run Rotella synthetic in the fall/winter 5W40, and Rotella conventional 15W40 in the spring/summer. I run the oil for 20K km's with oil filter changes every 5000km's.
 
Once a year on my truck (1999 F250 7.3 diesel), the diesel is dependent on good oil pressure for good operation. Not a mechanic, just was told to keep ahead of it.

On the older stuff, once a year because it is easier to remember, line them up and do them all the same day.


Alan
 
I change the oil in all of my vehicles annually. I use Amsoil in all of them and their filters. If Amsoil filters are not available, I use Wix, Donaldson or Hastings.
 
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