Owen Lucas
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I'll be changing the oil soon and give it a very distant sniff. We shall see.
The truth about oil change intervals and analysis
- Thread starter FMC
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Well mostly true in NA engines, but turbo engines under load typically map richer, especially normally lean burn turbos.
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Does spark knock equal more fuel dilution?
Do some UOA's on the fleet. I missed doing it last time as I promised The Critic.
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OK, but that would mean they burn richer despite fuel octane choice, right?
Not necessarily, only if knock detected - which happens under the high load (high pressure) situations with lower rated fuels.
Mileage isn't a a good indicator of oil life for many anyhow.
Engine hours is better. Even better is a setup that calculates oil life.
Mileage may be fine for a setup running highway like a L48 long haul driver. Otherwise is doesn't account for idle or slow driving.
IE my work truck has about 8900hrs and 25k miles.
It's had about 35 oil changes. If I did 3000 miles, that's only about 8.
Engine hours is better. Even better is a setup that calculates oil life.
Mileage may be fine for a setup running highway like a L48 long haul driver. Otherwise is doesn't account for idle or slow driving.
IE my work truck has about 8900hrs and 25k miles.
It's had about 35 oil changes. If I did 3000 miles, that's only about 8.
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OVERKILL
$100 Site Donor 2021
If you have LSPI, you are probably only going to have it once. It tends to be devastating, which is why there has been so much work put in to avoiding it entirely. On the other hand, conventional pinging/spark knock, which is why engines have knock sensors, is controlled through ignition timing of course, but also through enrichment and injection timing with GDI. This is particularly true for TGDI engines where enrichment and injector timing enable compression ratios that aren't possible with port injection, let alone on regular fuel. If the amount of enrichment and injector timing can be influenced through using higher octane, using feedback from the knock sensor, then this can have a positive effect on reducing the amount of fuel that makes its way into the sump.
Truck i was running last week had just over 100k miles and 26,000 hrs. F550 flatbed.
OVERKILL
$100 Site Donor 2021
Yup, an IOLM that takes into account operating conditions is about as "good as it gets" for a predictive system, as hours don't account for operating temperature (or whether it gets up to it at all thanks to short tripping), how much fuel is being consumed, average load...etc. Going by miles is even worse as it doesn't factor in hours along with any of those factors.
A good dialog for these guys would be,
"So frequent oil changes are good. Should I change my oil every 100 miles?"
"No, that's too often."
"Should I change it every 1000 miles?"
"No, that's too often."
...
"Should I change it every 3000 miles?"
"Yes, that's about right."
"Why? What data do you have to recommend 3000 instead of 2000 or 4000?"
If they don't have data, they're just rehashing talking points from somebody else.
"So frequent oil changes are good. Should I change my oil every 100 miles?"
"No, that's too often."
"Should I change it every 1000 miles?"
"No, that's too often."
...
"Should I change it every 3000 miles?"
"Yes, that's about right."
"Why? What data do you have to recommend 3000 instead of 2000 or 4000?"
If they don't have data, they're just rehashing talking points from somebody else.
It's not talking points, its science over speculation.
No. OEM tunes are generally not setup for more fueling when spark knock is detected. If anyone wants to prove otherwise, they should post the tables from the ECU software. Otherwise, it is speculation at best.
Are you talking NA? Yes I agree. Or are you talking turbo engines? You need to make the distinction.
I don't have tables. I think you knew that.
I know for a fact Volvo did this for years in their turbo engines. Does Honda do this? I don't know for sure. Not sure how to find out. You probably could and I trust you.
I will get back to you at 300,000 miles, Lake.
OVERKILL
$100 Site Donor 2021
3,000 miles is not science, it's literally the antithesis of science because it's predicated on absolutely no operating data.
Your interpretation of the warranty comment and mine are different.
it’s a whole lot easier to make a LOT of money selling $70-100 oil analysis when your overarching recommendation is “change it every 3k, AND MAKE SURE to send in another sample so we can make sure you’re not going to damage your engine!” Just another shock jock.
If you’ve got a vehicle that is regularly used in fleets, and have access to their oil & OCI data, it’s nearly a guarantee that if you use both those data points you’ll be fine… private owner use is almost never as brutal or disregarding of the machinery as fleet use is.
Remember Crown Vic cop cars & taxis? If you had access to PD data and they were using Chevron conventional 10w30 on 10k OCIs regardless of hours and had even just an average failure rate compared to CVs as a whole, I personally would run that oil & OCI for 10k with abandon, because I know I’m not using the throttle as an on/off switch, nor letting the engine idle for hundreds (thousands?) of hours during said OCI.
I just hit 3 years and 4 months of ownership on my F150, and over that whole time in Midwest winters and 58k+ miles of driving, have just now accumulated 100 hours of idle time and turned over 82k total miles. The previous owner, who had the truck from new to 23,800 miles had idled for 192 hours in his time. My use case is easy street compared to most.
Haven’t seen this in any of the Nissan VQ engines we’ve tuned, NA and turbo.
I stand by my statement. Until someone wants to post ECU tables showing this to be part of Honda’s fueling strategy, it is speculation at best.
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