It’s wise to let the engine idle for up to 10 seconds after oil pressure builds.
It takes a few seconds for oil to fully flood critical parts of the overhead.
OCI recommendation for TGDI?
- Thread starter majestic_lurker
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It takes a few seconds for oil to fully flood critical parts of the overhead.
edyvw
$50 site donor 2025
I would say they are exception to the rule.
I usually let stuff run 30-45+ mins.
I have no desire to try to drive in a -30* cab with the windows iced over.
You do realize that type of decision is completely arbitrary and not based in science? If you had said something like, "I've established long-term trends for my specific engine and driving habits, and I change the oil if either fuel % or oxidation are outside the upper control limits," that would both make sense and be sensible. There are also other valid methods for determining condemnation points as well that are both based in science and practiced in fleets. Dumping oil based on one or two measurements being "just higher than the average" is not.
Are you taking averages of average miles traveled to determine what your overall average per thousand miles is? Neither fuel accumulation nor oxidation trend linearly like iron or copper generally do (i.e., longer time in service results in increasing measurements). You're obviously free to do whatever you want, but don't think that this way is being statistically sound.
I'm not sure how new your Mazda is, but for that model if it still under manufacturer warranty, the OCI is 12 months OR 10K miles (whichever comes first) or 6 months OR 5K miles for "severe service" which "long idling" falls under. The 2.5T has been out for a while and is used in every model except the Miata and CX-70/90 but the UOAs I've seen on it are that it is a moderate fuel diluter so keep that in mind too. I'm not here to tell you which way to proceed but I can tell you that a dealership service dept would raise their brows at records of you changing your oil every couple of years and then having an issue.
As noted earlier, 2.5T is 5W-30, 2.5 naturally aspirated is 0W-20. Again, decide how you wish to proceed.
*Edit* I just re-read your initial post about it being a 2024, so assuming you haven't driven past 60K miles, you are still under the mfr warranty (5 years/60K for powertrain).
As noted earlier, 2.5T is 5W-30, 2.5 naturally aspirated is 0W-20. Again, decide how you wish to proceed.
*Edit* I just re-read your initial post about it being a 2024, so assuming you haven't driven past 60K miles, you are still under the mfr warranty (5 years/60K for powertrain).
you dont have a ice scraper? here the engine idle for like a min then we drive, letting something idle up to temp is horrible.
When it's really cold, the engine will high-idle (1500-2000rpm) for an extended period of time. Slamming the transmission with a high idle engine doesn't do it any good either. It all depends on the vehicle and the environment.
The Skyactiv Mazdas drop the high idle as soon as you pull the transmission lever out of Park or Neutral. They don’t slam into Drive or Reverse at high idle, if that makes sense.
Well, however arbitrary it may seem, it IS based on trended analysis for my cars and application, ie; driving style etc. I understand that the 2 parameters I've set are not linear and that is why I chose them for a RELATIVE gauge on when to dump the oil. The "meet in the middle" point from averaging my UOAs gave me a rather consistent max. range to use. It's kind of like the older algorithms used by BMW for their oil life indicators that used several different parameters to determine oil life rather than just fuel usage. Combustion efficiency took a nose dive when these reached my self set upper limits too. Plus, I had 2 tribologists with many years experience (NOT B-stone or LSJr
) both interpret my results each time and they agreed the oil was due when fuel and oxidation hit my points because of other things they saw. This made the self set limits pretty consistent for my use (all of my cars are VW TGDI currently) and why I decided to go by them. YMMV.
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Yeah I wasn’t arguing with the idea of using those indicators as a time to change; just that changing them any time they’re above the average at all. There’s definitely reasons on both of those to change, just that using the average rather than the upper control limit dictated by your trends means you’ll likely shortchange your OCIs. Since they don’t increase linearly, a sample at 10k could be just above the average, but you may go another 10k and they’d still be lower than the upper control limit, meaning you doubled your oil change frequency for something that was still well within the safety range.Well, however arbitrary it may seem, it IS based on trended analysis for my cars and application, ie; driving style etc. I understand that the 2 parameters I've set are not linear and that is why I chose them for a RELATIVE gauge on when to dump the oil. The "meet in the middle" point from averaging my UOAs gave me a rather consistent max. range to use. It's kind of like the older algorithms used by BMW for their oil life indicators that used several different parameters to determine oil life rather than just fuel usage. Combustion efficiency took a nose dive when these reached my self set upper limits too. Plus, I had 2 tribologists with many years experience (NOT B-stone or LSJr
The inside ices up as well. And gets worse if people get in the truck before it's warmed up.
At around -30* and colder I just let the truck stay running. Too many issue with steering lines and pumps otherwise and that's way more expensive than ~$50 of gas a day.
The older trucks all had high idle switches. Like my 7.3L F350 is an old slope truck, it will idle at 1200 rpm I think, maybe it's 1400, if I hit the switch.
Understood. Guess I wasn't too clear that these upper limits were based on averages and when the other aspects of my oil started to downturn. Just for grins, I took a couple out a few thousand more miles past the original UOA and the wear metals and contamination rose rapidly. So, again for me and my usage, it made it pretty easy to see the correlation and determine where the oil was done and needed a change.Yeah I wasn’t arguing with the idea of using those indicators as a time to change; just that changing them any time they’re above the average at all. There’s definitely reasons on both of those to change, just that using the average rather than the upper control limit dictated by your trends means you’ll likely shortchange your OCIs. Since they don’t increase linearly, a sample at 10k could be just above the average, but you may go another 10k and they’d still be lower than the upper control limit, meaning you doubled your oil change frequency for something that was still well within the safety range.
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