Oil Change Intervals 3k vs Longer with full synthetic

What's the deal with that engine? I've had two neighbors with it that had an amazing amount of oil usage. Seems like a good candidate for Valvoline R&P, but maybe it goes beyond that.
It goes beyond any oil. It’s to the point that anyone who purposely buys H/Ks don’t deserve sympathy when hard parts decide to spontaneously dissociate 🤪
 
I’d personally get rid of any vehicle that “needs” 3k oil changes. The risk of failure and the increased operating costs over the life of the vehicle make less sense than getting rid of said vehicle for something less fragile.
Yep! And not because of the cost of oil (cheap!), but because of risk avoidance.
 
As oils have improved, most engines have become harder on oil. It’s an arms race. I’m now often not comfortable telling someone how long they should run an oil. I would feel terrible if my suggestion caused problems later on. We’ve lately seen quite a bit of evidence of big brand synthetic oils failing in the deposit category.
 
I was taught the old way of changing oil and filter every 3k miles as regular routine maintenance and i know oil has changed a lot over the years
Even though i run Mobil 1 Full synthetic in all my cars now i still have a hard time going over the 3k miles without doing an oil change
I would never consider going 7500 10000 miles ever and i know some people say that's fine to do but I'm not willing to take the risk
What are thoughts about 5K mile oil change intervals I run full synthetic Mobil 1 in the engines and usually run stock filters
Mopar in dodge, Mobis in hyundai, and i use napagold/wix in the wifes honda
My hyundai i will stick to 3k simply because its gdi and i spray intake valve cleaner into the engine every oil change to try to minimize carbon buildup on the valves. I also have a 20 year old pontiac that ill stick with 3k simply due to it being an older car now. is it worth sticking to 3k oil changes just to maximize engine protection?
It largely depends on engine design and type of driving you do. A Hyundai Theta II or Nu driven 75% city miles, I don't think you could change the oil frequently enough to keep the rings from sticking. A Toyota anything with dual injection (MPI and GDI) and 75% or better highway miles., I would not be concerned with 5000 - 6500 mile oil changes.
 
My Corvette has direct injection and I have no concerns with doing 7k intervals. In fact I have a 7400 mile UOA on here showing 0% fuel and no other issues with going that long. So I will continue to follow my oil life monitor just like I have always done with every car that has one.
Well from what the lab told me if you're showing 0% fuel then the equipment is broken. Even my VOA showed slight fuel.
 
Well from what the lab told me if you're showing 0% fuel then the equipment is broken. Even my VOA showed slight fuel.
I can assure you that Wearcheck doesn’t operate like that. They use the GC method to calculate fuel and aren’t the type of lab that would allow for broken equipment. It’s likely that they saw 0.3% fuel and simply rounded down on the report.
 
Well from what the lab told me if you're showing 0% fuel then the equipment is broken. Even my VOA showed slight fuel.

I can assure you that Wearcheck doesn’t operate like that. They use the GC method to calculate fuel and aren’t the type of lab that would allow for broken equipment. It’s likely that they saw 0.3% fuel and simply rounded down on the report.
My tuned 3.5 EcoBoost at 14.4k on HPL Euro No VII had fuel <1% on GC as well. To me that’s also basically a rounding error, not anything of concern nor a failure of the equipment.

On the other side of the coin, my Ascent FA24 had 6% at 7300 miles. I’m seriously wondering if a tune would bring the fuel down on the Ascent.
 
My tuned 3.5 EcoBoost at 14.4k on HPL Euro No VII had fuel <1% on GC as well. To me that’s also basically a rounding error, not anything of concern nor a failure of the equipment.

On the other side of the coin, my Ascent FA24 had 6% at 7300 miles. I’m seriously wondering if a tune would bring the fuel down on the Ascent.
When I had my 2006 Civic I was having some problems starting when it sat for about 8 hours or more. It would take a lot of cranking to get it to fire up. I suspected that one of the injectors was leaking down. My Wearcheck UOA showed 7% fuel! So I gave it a few doses of Gumout Regane and almost immediately the starting problem went away. My next UOA after that showed 2% fuel and then the one after that showed none.
 
When I had my 2006 Civic I was having some problems starting when it sat for about 8 hours or more. It would take a lot of cranking to get it to fire up. I suspected that one of the injectors was leaking down. My Wearcheck UOA showed 7% fuel! So I gave it a few doses of Gumout Regane and almost immediately the starting problem went away. My next UOA after that showed 2% fuel and then the one after that showed none.
Curious, were you using top tier fuel?

I throw in a bottle of Amsoil fuel injector cleaner every 4000 miles.
 
Curious, were you using top tier fuel?

I throw in a bottle of Amsoil fuel injector cleaner every 4000 miles.
I was using mostly Top Tier fuel back then as well as running a bottle of Gumout once a year. I did more short trips with that car back then though so that might account for the injector issue (which never returned after I solved it)
 
Does anyone know the timeline of oil change interval recomendations through the years? My earliest recollection would be 3k and that was probably early 80's. That was before plastic bottles, synthetics and fuel injection. I would think a carburetor that has to be pumped a few times to set the choke every morning is going to dilute the oil with just the startup procedure. And then the carburetor vs efi efficiency aspect. When is the last time you heard someone say that their motor is flooded? Anyone have a used oil analysis from the 70's, 80's or 90's?
 
It surprises me when I hear about members here who have one of these Kia/Hyundai GDI vehicles that are so failure prone unless you change the oil at such low intervals. Didn’t they do any research before buying? There’s so many other choices they could have gone with that aren’t so sensitive to oil choice/interval.
yes when i bought it in 2015 i had no clue about gdi but quickly learned after researching it
I kept hearing pinging under light throttle took it to hyundai of course nothings wrong that's normal for that engine was the claim
No it was pinging/detonating under acceleration at less than 50,000 miles it already had carbon building up on the valves
that was when i started doing oil changes every 3k miles and i also spray crc gdi intake cleaner into the motor every oil change to help dissolve some of that gunk off the valves it usually smokes like a diesel for a few miles after i do it but no more pinging and average 45 mpg still at 129,00 miles now i feel bad for the people who bought gdi cars and have no ideas about the design flaws or extra maintenance needed with them and their engines are going to fail early due to oil consumption and carbon buildup i know some manufacturers combind gdi with port injection which was a slightly improved design
 
yes when i bought it in 2015 i had no clue about gdi but quickly learned after researching it
I kept hearing pinging under light throttle took it to hyundai of course nothings wrong that's normal for that engine was the claim
No it was pinging/detonating under acceleration at less than 50,000 miles it already had carbon building up on the valves
that was when i started doing oil changes every 3k miles and i also spray crc gdi intake cleaner into the motor every oil change to help dissolve some of that gunk off the valves it usually smokes like a diesel for a few miles after i do it but no more pinging and average 45 mpg still at 129,00 miles now i feel bad for the people who bought gdi cars and have no ideas about the design flaws or extra maintenance needed with them and their engines are going to fail early due to oil consumption and carbon buildup i know some manufacturers combind gdi with port injection which was a slightly improved design
Did you get any engine codes when you had that problem?

That’s pretty severe carbon buildup.
 
My driving is not severe. Lots of highway cruising, just a little over the speed limit. I guess that's why the mileage monitor recommends such long intervals for me.
Same with me in my Civic. It’s never short tripped, it spends 90% of its time on the highway and I stay close to or slightly over the speed limits (generally no more than 10 kmh over) That’s why my oil life monitor hits zero at around 10,000 miles.
 
Sometime short OCI’s makes sense.

The Hyundai gets seasonal changes (spring/fall) due to all short trips. Typically it’s only driven a few miles at a time which equates to approximately 100 miles each month.

I don’t think I’d be comfortable going 30 or more months with all trips. Yeah it’s a beater but it’s still in decent condition. I don’t want to ruin the engine just to be an oil tightwad.

Now I could do some UOA’s however the cost is suspiciously similar to that of oil changes. So why bother.
 
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