Do some ECUs adjust for oil pressure?

SiRDOHC

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Bump because I am finally going to get around to changing back to 0w20 tomorrow to see the effects. Was hoping to get some insight on how I could quantitatively compare the lower visc to the higher viscosity. The only tool that records data that I have is the dash command app. I will make some videos driving on the same roads while recording the data on dashcommand.

I found this old thread which is more of what I meant when i first asked the question.

Different Vvt calibration for different oil weight
 

SiRDOHC

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Think about this scenario. Every time you start your vehicle with a cold engine (even on an 80F day) the oil is orders of magnitude more viscous than at operating temp. The engine and all of its components must have some way of adjusting for this increased viscosity until the engine oil is at operating temp. The difference between cold/cool 0W20 and hot 0W20 or 0W30 or 0W40 is very significant but no one talks about their cars feeling supercharged during warm-up only to have it disappear at operating temp. Engines must be designed to be able to adjust for a wide range of viscosities during operation.

This is the funny thing about this vehicle. It does feel supercharged (in comparison of course) while it is warming up, when using a lower viscosity oil as recommended. Once it warms up to operating temperature, it just drops, like a stone, into a mode, which completely retards the timing and alters the throttle response to something I don't consider tolerable or safe. Fuel efficiency is fantastic in this mode, but that makes sense because it is cutting power most of the time to achieve that. - It doesn't drop into this lethargic ECO mode when a high viscosity oil is used even when fully warmed up.

Update:
I did switch back to 0w20 and the throttle response has again died and the timing values have noticeably changed. It's not in my head. If you think so please move on. I have to find some time to make some videos to show the differences in throttle behavior and performance, and create some corresponding data logs from the obd2 scanner, but you can respect that collecting this data and making these videos in even a quasi scientific way will be time consuming. I have to find time to drive on the same stretches of road with both viscosities, in similar enough weather, with minimal traffic etc. What I would like to do is pair the logs with the videos, so the relationship between viscosity and on the fly ECU tuning can be looked at by anyone interested.

I have confirmed that it isn't only hydraulic pressure based tuning because even when using the lower viscosity 0w20, I can trick the system out of its ECO mode by unplugging one of the two clutch switches. Under this hack that does throw a CEL, the fuel efficiency goes back to terrible, but full throttle response is restored, rev hang pretty much disappears, and it pulls its hardest up to redline whenever called upon, irrespective of the gear you are in.
 
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This is the funny thing about this vehicle. It does feel supercharged (in comparison of course) while it is warming up, when using a lower viscosity oil as recommended. Once it warms up to operating temperature, it just drops, like a stone, into a mode, which completely retards the timing and alters the throttle response to something I don't consider tolerable or safe. Fuel efficiency is fantastic in this mode, but that makes sense because it is cutting power most of the time to achieve that. - It doesn't drop into this lethargic ECO mode when a high viscosity oil is used even when fully warmed up.

Update:
I did switch back to 0w20 and the throttle response has again died and the timing values have noticeably changed. It's not in my head. If you think so please move on. I have to find some time to make some videos to show the differences in throttle behavior and performance, and create some corresponding data logs from the obd2 scanner, but you can respect that collecting this data and making these videos in even a quasi scientific way will be time consuming. I have to find time to drive on the same stretches of road with both viscosities, in similar enough weather, with minimal traffic etc. What I would like to do is pair the logs with the videos, so the relationship between viscosity and on the fly ECU tuning can be looked at by anyone interested.

I have confirmed that it isn't only hydraulic pressure based tuning because even when using the lower viscosity 0w20, I can trick the system out of its ECO mode by unplugging one of the two clutch switches. Under this hack that does throw a CEL, the fuel efficiency goes back to terrible, but full throttle response is restored, rev hang pretty much disappears, and it pulls its hardest up to redline whenever called upon, irrespective of the gear you are in.
Maybe because of some mechanical fault (worn bearings, worn out or defective oil pump, etc) thicker oil increases your oil pressure and actuates the vanos better.
 

OVERKILL

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My 2022 trailboss has an electric oil pump that adjust for all sorts of things.
Electric oil pump, or electronically controlled oil pump? There are plenty of the latter on the market, but don't think I've seen an engine with a fully electric oil pump.
 

OVERKILL

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Nope full on electric oil pump, 2.7 ho turbo
That's not what I'm finding for the L3B. It has a variable displacement oil pump, driven off the crankshaft. It does however, have an electric water pump.
The engine is equipped with a continuously variable-output oil pump. The oil pump, together with balance shafts, is supported by a bolt-on aluminum lower crankcase extension.

If you've got another source that contradicts this info, would like to see it.
 
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I searched this site and everywhere else all I could find were some scion frs/86/brz guys talking about this phenomenon I have experienced when using heavier weights but here goes with a bit of background…

I’ve been driving smaller 4 cylinder cars since the 90’s and I have come to know what kind of power to expect based on the vehicle’s power to weight ratio and gearing.

Most of these cars were 80’s 90’s early 00’s without electronic throttle so what your right foot put into the equation was exactly what you got out of the engine power wise. My most recent vehicle I have owned for 8years now, a ‘13 mazda2 5spd. Older engine design retrofitted to drive by wire at some point , I would assume for emissions purposes. Up until this summer I was a good boy and followed the OM and used 0w20, except for the time I tried m1 0w30 afe. Mileage has been good, but not stellar for a small car with a manual. The engine is low mileage and in good overall health except the thing would just not rev and breathe and give me everything it had in it when I put my foot into it, especially around downshifts and upshifts.

Sump holds 4L, and I had 3L of PP Euro LX 0w30 leftover from another car and went out and bought a 1L of M1 0w40 euro and dumped it in for this year’s oil change. I wish I had tried this sooner because it has drastically reduced rev hang and improved throttle response, in any gear, at any speed, the car now accelerates as a 2300lb vehicle should. If I can keep my foot out of it mileage hasn’t really changed. If I am driving spiritedly the mileage is down, because more fuel is being burned with the additional air that is being let in. Smiles per gallon have gone up :)

My question to everyone is have you experienced this with any other makes, models? I can only assume its an on the fly adjustment the ECU makes based on oil pressure which is now considerably higher with the heavier weight, euro oils.
Using a different type of oil doesn't affect how an engine runs. Thicker oil will reduce the fuel economy and make the car feel more sluggish at low throttle, but that's all.
 
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A lot of cars like VTEC, Nissan DOHC engines, their VVT systems (VTEC on a Honda, anyone?) are operated based off oil pressure so it certainly does matter.

Now, you're asking if an engine CPU can make adjustments based on a reading off an OPSU.. that, I don't know, seems unlikely to me though cars ARE becoming more sophisticated. Your engine acting differently based on a more viscous oil tells me maybe something has changed, that as @eljefino mentioned maybe the oil rings were showing their age and probably would have done so on any thicker HTHS within the grade oil, M1 0W-40 is a thin 40 and much loved.

I am not a tribologist but I do read and get educated from here, knowledge bank grows every day.
Variable valve timing systems use oil as a hydraulic fluid to move the timing gears advanced or retarded, it does not matter what the viscosity is, and the only time I've seen oil cause an issue with VVT is if there isn't enough of it or the fine mesh screens have been clogged with sludge from neglect.
 
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So I think the key phrase in here is "according to the PCM Signal". So again the engine control computer is deciding what the cam advance position should be, it sends a signal so the hydraulic pressure from the oil pump can move the cams, and then I assume this engine also has cam sensors which will verify back to the PCM the actual cam position. So the viscosity doesn't matter because the PCM will continue driving the cams to the position it wants until the cam sensors say its there.

If it never gets to position you will get an error code - so the oil pressure will affect it from that standpoint. Also the wrong viscosity might slow response of the actual positioners, which I suppose could also make it feel slugish.

At least that is the way any I have worked on operate , but I am a shade tree mechanic and my sample size is very small, so I am certainly not any kind of authority on the matter.
This is exactly how it works, and the only way you get a DTC is if the control valves are clogged or starved of oil.
 

SiRDOHC

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Maybe because of some mechanical fault (worn bearings, worn out or defective oil pump, etc) thicker oil increases your oil pressure and actuates the vanos better.
Ive driven this car since 6k miles and have driven others. They all have had the same performance characteristics. Its not worn out at the mere 47k miles it’s got on the clock.

Read the last paragraph of what you responded to, I am able to trick the ECU to dropping out of the Eco mode into a more responsive mode even while using lower viscosity oil by permanently keeping the upper clutch sensor removed. (Ecu thinks the clutch is pressed down and shifting is in between gears and that I have never completed a shift).
Using a different type of oil doesn't affect how an engine runs. Thicker oil will reduce the fuel economy and make the car feel more sluggish at low throttle, but that's all.
I understand this and agree, all things being equal. I’m not saying the car is faster when running thicker oil all things being equal. What I’m saying is all things are not equal - something happens hydraulically and then electronically within the engine when the viscosity drops below a certain threshold. When running 0w20 its fine until the engine starts approaching operating temp when it starts to cut power. It happens in the winter too, but takes longer. I can’t get that same thing to happen when running a higher viscosity like a 0w40, no matter how hot it is outside or how hard I run the car. It’s an electronic tuning thing that is actuated by hydraulic pressure.
 
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I understand this and agree, all things being equal. I’m not saying the car is faster when running thicker oil all things being equal. What I’m saying is all things are not equal - something happens hydraulically and then electronically within the engine when the viscosity drops below a certain threshold. When running 0w20 its fine until the engine starts approaching operating temp when it starts to cut power. It happens in the winter too, but takes longer. I can’t get that same thing to happen when running a higher viscosity like a 0w40, no matter how hot it is outside or how hard I run the car. It’s an electronic tuning thing that is actuated by hydraulic pressure.
So, you're saying that you have a faulty VVT-i actuator that requires higher oil pressure than normal?

Why don't you replace your oil-pressure switch with an oil-pressure sensor and see what is going on.

 
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Overkill, I was wrong about the oil pump, it’s a variable speed pump, not sure where I got the electric pump from.
 
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@SC Maintenance - in vw/audi, if you are low on oil or have low oil pressure, the electronic throttle will be limited by the dme. It will be put into limp mode and limit the rpm. It also does this if your oil temp is too high. Just one example of how a dme/ecu can use oil parameters to limit throttle inputs.

@OVERKILL your assumption about the different FM in Euro oils having an effect on timing events might not be as far fetched as you think. I buy and help my friends and family buy Euro cars all the time, usually at mom and pop dealers. First thing I do is dump the dealer fill, which we all know is bulk oil that they get at a good price point, then fill them with the approved oil and take them for a ride.

At this point, I take them for a ride. I understand my own ride can be "faster" due to the placebo effects, however friends and family notice it too after they leave the car with me to "look it over" and totally unaware of me changing oil to an approved oil, usually in the x-40 range. When they pick it up, I get asked if I "tuned it up" as they notice improved throttle response, smoother running, etc. Granted, friends and family car knowledge range from baby Yoda to Scotty Kilmer to Gale Banks.

Maybe you're on to something, maybe we all suffer from the placebo effect.
 
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@SiRDOHC how far does your interest in your topic go??? If you really are curious, pick up a obd2 reader that can log your oil pressure, throttle angle, rpm, and cam angle. Plot them against each other using different grades of oil controlling parameters such as weather.

If these do not provide the speed you need for logging, maybe pick up a sn65hvd can board and a teensy 4.x and whip up something that logs your pid's at high speed.
 
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(For an LS, LS1) Poster states that the PCM has both upper and lower limit the activation for VVT.

https://ls1tech.com/forums/generation-iv-internal-engine/1607960-vvt-oil-pressure.html#post16977369

Seems that oil pressure is very important with these systems.
LS1/LS2/LS3 does not have VVT. Some LS based engines do, mostly truck/suv variants and those in none high performance cars that gm offers. Only hp offering that I'm aware of having vvt is the l99 in the 4th generation camaro with the auto transmission. I could be wrong.
 
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@SC Maintenance - in vw/audi, if you are low on oil or have low oil pressure, the electronic throttle will be limited by the dme. It will be put into limp mode and limit the rpm. It also does this if your oil temp is too high. Just one example of how a dme/ecu can use oil parameters to limit throttle inputs.
The VW stuff are fail safe's I presume.? I didn't seem to think this was what the OP was asking about,

He seems to have performance improvement due to higher oil pressure and was asking if the ECU could possibly advance VVT or timing based on slightly higher oil pressure, to which I think the answer is still no. I should have been more specific.

Even in the 90's GM vehicles would shut the car down if the oil pressure went too low (it usually happened because the stupid sensor failed then you needed a tow. Most modern vehicles will go into limp mode. Modern Toyota's will actually drop oil pressure to save fuel under low loads. I didn't seem to think this was what the OP was asking about.
 
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He seems to have performance improvement due to higher oil pressure and was asking if the ECU could possibly advance VVT or timing based on slightly higher oil pressure, to which I think the answer is still no. I should have been more specific.
In my past experience, I'd have to say maybe bordering on yes. Myself and friends/family noticed a difference when swapping to Euro oils in Euro cars, at times totally unaware of the swap. Maybe our friend Overkill is not far off on his idea of FMs effects on timing events.

Without logs in controlled environments, about as close as oil nerds on this site can get, logging different PID and plotting them against each other with the only variable being the oil, we can both be wrong or right. Hence why I pitched some obd2 logger.

Unless we get that going, we're going on driving feel, aka butt dyno. Placebo can have a big affect on the butt dyno, but when you take that out of the equation, ie person driving said car before and after knowticing a difference, you have to give the butt dyno a bit of credit.

Call me crazy, but I tend to believe a guy, the op, that's been driving his car 40k to be able to tell a bit of difference when he changes something.

I'd say we're both right, maybe it's being right in equally being wrong. Unless logs are completed, driving feel is what we go about testing different variables.
 
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