Your Max OCI (in months) With Synthetic Oils ?

Wife's mazda is down to just under 5k a year with work-from-home so it's now on a 12 month interval.
 
I'm at 3 years - about 3k miles - right now on my 96 F150. She burns a little, so I have added maybe 2 quarts in that 3 year period.

I bought the truck for $1400 6 years ago and have put about 30k miles on it (almost all of the miles came in the first 2 years). Runs just fine.
 
Just did 6 mo, 2900mi on my Ford problematic GDI just driven mainly in town short trips. It only went that far due to the QS10W30 FS I was running.
Switched to 5w20 for Winter. Big mistake. Engine sounds like a bucket of parts rattling around in just 2-1/2 months.
This engine is shot IMHO. May just be VVT but could be piston skirt or rod bearing as it get noisey as you unload the engine when revving it in Neutral or manually shifting the autobox in S mode.

I do NOT intend to go to the dealer for repairs and get a BIG Black Mark on the stupid carfax report - unless it blows on the road.

On the wife's old 2017 subaru crosstrek (a P.I motor) went 5 month and 9300 miles on a Valvoline / Magnetech mixture.

Oil came out looking fantastic for miles accrued UOA showed nothing wrong whatsoever. BUT! She does a LOT of high speed highway with regular hour long one-way drivetimes.

Chris you have been agonizing about that Hyundai for over a year. I think its time we dump both of our cars.
The grass is always greener :)

I am waithing for a classic B or C body 2dr HT or a stupid camaro v8 LT-1
 
I'm debating this question (with myself) right now. The Mercedes has 1 year on the oil, but only about 2000 miles. Only a SINGLE long trip in all that time!
So short trips, turbo, so fuel dilution (I can smell it), all on Ravenol VST. Not 100% sure fuel dilution causes any issues though.
Pretty sure it's gotta go, but likely not change the filter.
Thoughts?
 
I go by mileage (I like even mileage intervals) and the maintenance minder on all three cars, and don't worry about the length of time. Usually works out to about 1 to 1.5 years for each since miles are spread between three cars.
My bike gets an oil and filter every two years which is usually around 1200 to 1500 miles. The key being a good long highway run (min one hour) to remove any moisture before storing for the winter. Could possibly go longer, but two years is long enough for me.
 
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I'm debating this question (with myself) right now. The Mercedes has 1 year on the oil, but only about 2000 miles. Only a SINGLE long trip in all that time!
So short trips, turbo, so fuel dilution (I can smell it), all on Ravenol VST. Not 100% sure fuel dilution causes any issues though.
Pretty sure it's gotta go, but likely not change the filter.
Thoughts?
What does the maintenance minder say? If it indicates (for example) 60% oil life remaining I would go further. If it's down to something like 30% then I would change the oil and filter both.
 
I would go up to 1 year if the mileage interval is not met. Mostly easy miles, engine is kind to oil, relatively large sump capacity, running oversize filter and full syn oil (conventional is spec'd), engine spends plenty of time at full temp.
 
One year.
Last two OCI were 2900 and 3300 miles.
In late March, on a day with mild weather.
Typically 2 drives per week plus road trips.
 
6 months for me.
We have a car that we short trip (honda 3.5 v6 with 200k miles). It may get used 5 times per week and only go 2 miles round trip some days.
I just changed the oil last week after about 6 months/ 1k miles and oil looked great/clean and the motor was very clean (although the engine has taken on a bronze tint) when I did the valve adjustment last time a few months ago.

$24 oil change gives me inexpensive peace of mind, I guess.

Edit to add: I did change the oil after just a few hundred miles in a 5.3 chevy recently. I used motor flush in it (was curious and had it laying around for some reason). I followed the directions on the bottle and fresh oil went in after the flush but that fresh oil was BLACK after just a couple hundred miles and my oil pressure was slowly dropping from normal value. Changed the oil and filter and pressure jumped back up. I guess that motor flush wasn't done working yet.
 
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6 months or 5,000 miles is my rule of thumb, whichever comes first. My car I’d be more willing to push to 7,500 since I do about 70/30 highway city driving, but the wife’s car is short tripped. We only live about 2.5 miles from her job so often times hers doesn’t even make it to 5k just changed every 6 months which is usually ~3500-4000 miles.
 
Wife’ Jeep last OCI was 10months/6k miles. Now she does even less driving; so the Edge 5W-20EP will go a whole year until next fall. Even with all short trips, oil will be robust enough I think.
 
6 months even if the oil only has a few thousand kilometres on it. People on here like to tell me I'm changing too early and I'm wasting oil, but my driving patterns (almost no highway driving) always result in viscosity being out of spec after 6 months with every car I own. So yeah, I think I'm not wasting oil at all, but rather doing exactly what I need to in order to keep my engines running well.
 
unless there is a warranty concern, 24 months, unless it is the sportster in which case it gets ridden so little it is basically forever oil...
 
6 months or 5k kms in my HFV6 holden commodore. It gets a mix of highway and short trips however It gets a fair bit of idle time with ac on hence the short oci.
 
Every 2 years in my classics (67 Camaro and 65 Vette) and garage queens 2011 Grand Sport and Challenger Hellcat. Once a year in everything else.
 
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