Engine oil pressure difference Mobil1 M1-201 vs M1-201a

[Sierra977]

For years used Mobil1 oil filter M1-201 (with Mobil1 10W-30 oil). Recently changed to filter M1-201a as the -201 is no longer available. Engine oil pressure indicated several pounds LOWER with the M1-201a oil filter. Is this normal?
If I change to a different filter, what is a good choice?
Thank you.

 

[BAJA_05]

Bang for the buck -- Fram Ultra -- I usually run them out to 15,xxx miles or 3 oil changes. Fram Ultras are rated for 20,000 miles right now.

 

[Sierra977]

Bang for the buck -- Fram Ultra -- I usually run them out to 15,xxx miles or 3 oil changes. Fram Ultras are rated for 20,000 miles right now.

Thank you for the input.
Are WIX filters good also?
Any other premium quality filters?
Application is a 1992 Chevrolet K1500 Suburban 5.7 gasoline truck with 410,000 miles that I have owned since new. Never a problem and engine or trans have never been opened.
ETA: Tried TWO different M1-201A filters. First time, thought the tech did not change out the M1-201 filter as the new M1-201A exhibited the same oil pressure as the old, used M1-201 filter. In the past, when changing M1-201 filters, the engine oil pressure increased a few pounds each time a new M1-201 was installed at oil change.
Both M1-201A filters have had the same lower engine oil pressure when new.
I think I have a right to be concerned.

 

[kschachn]

How are you measuring it exactly? What kind of device and how are you correcting for temperature and RPM? A “few pounds” of pressure difference is difficult to measure accurately at identical conditions.

 

[slacktide_bitog]

This filter doesn't have a bypass valve, since there is one in the block on the cars it's used on.

As long as the pressure isn't in the red zone, really low, you're fine

 

[BAJA_05]

Thank you for the input.
Are WIX filters good also?
Any other premium quality filters?
Application is a 1992 Chevrolet K1500 Suburban 5.7 gasoline truck with 410,000 miles that I have owned since new. Never a problem and engine or trans have never been opened.
ETA: Tried TWO different M1-201A filters. First time, thought the tech did not change out the M1-201 filter as the new M1-201A exhibited the same oil pressure as the old, used M1-201 filter. In the past, when changing M1-201 filters, the engine oil pressure increased a few pounds each time a new M1-201 was installed at oil change.
Both M1-201A filters have had the same lower engine oil pressure when new.
I think I have a right to be concerned.

Wix makes a quality filter also.

 

[Sierra977]

How are you measuring it exactly? What kind of device and how are you correcting for temperature and RPM? A “few pounds” of pressure difference is difficult to measure accurately at identical conditions.

Factory oil pressure gauge in dash. Works fine for twenty-eight years - no changes.
RPM read from factory tachometer in dash.
Factory equipped with 160F thermostat.
Truck built as CUCV for Dallas Fire Department, arrived dealer in August 1992 and DFD rejected delivery in order to get 1993 model. I found truck on dealer's used vehicle lot and bought it new/used.
Truck currently has 411,000 miles and engine/trans/transfer case/differentials never even been opened. Truck hopefully good for half-million miles. It's my daily driver.
ETA: 1992 was the last year civilians could buy new military vehicles like CUCVs. Bill Clinton put a stop to that with an executive order - that's also why diesel Hummers were so rare and expensive on the civilian market.
ETA2: Truck does not use ANY oil between changes. It's 100 percent factory stock and run M1 10W-30 since new.

 

[Sierra977]

This filter doesn't have a bypass valve, since there is one in the block on the cars it's used on.

As long as the pressure isn't in the red zone, really low, you're fine

I wonder of the old M1-201 has a bypass valve or if the different filter medium is what is causing the change?

 

[tblt44]

Wix have wire backed filters like ultra

 

[slacktide_bitog]

Wix have wire backed filters like ultra

yeah, the Wix XP aka Napa Platinum

 

[kschachn]

Factory oil pressure gauge in dash. Works fine for twenty-eight years - no changes.
RPM read from factory tachometer in dash.
Factory equipped with 160F thermostat.

So both the oil pressure gauge and the temperature gauge are real gauges and are capable of single-digit accuracy and resolution?

 

[ZeeOSix]

Application is a 1992 Chevrolet K1500 Suburban 5.7 gasoline truck ...

Isn't that the engine that has reported flaky oil pressure sensors now and then? Thing is, with a positive displacement oil pump the oil flow at any given RPM should remain the same unless the oil pump is in pressure relief mode. Really hard for me to believe that the pump is in pressure relief when the oil is at full operating temperature and the engine is at low RPM.

 

[Job]

You have an engine with over 400K, the oil filter is probably not the one to blame since it is a very simple device.
I never knew it was possib;e to ever order a military vehicle. But I know. like you did, you can buy police and fire vehicles second hand.

 

[LEADED]

Nothing beat a mechanical oil pressure gauge . I still have a very old Parker Hanifin very accurate no guesswork old school

 

[Sierra977]

Isn't that the engine that has reported flaky oil pressure sensors now and then? Thing is, with a positive displacement oil pump the oil flow at any given RPM should remain the same unless the oil pump is in pressure relief mode. Really hard for me to believe that the pump is in pressure relief when the oil is at full operating temperature and the engine is at low RPM.

IIRC Chevrolet calls the engine L05.
Dunno about flaky oil pressure sensors but interested.
Dunno what last sentence means but interested.
At operating temperature, which is on the low side of the TEMP gauge (remember 160F thermostat), oil pressure gauge has always shown an increase in pressure at rpm above idle. Still does. Indicated oil pressure peaks and remains stable above ~1,500 rpm.

 

[Sierra977]

You have an engine with over 400K, the oil filter is probably not the one to blame since it is a very simple device.
I never knew it was possib;e to ever order a military vehicle. But I know. like you did, you can buy police and fire vehicles second hand.

While **** Cheney was Secretary of Defense around 1989, he was responsible for changing defense procurement procedures to allow .mil purchase of less expensive "civilian" equivalents of various mil-spec items. The program has a name and I cannot remember it. This allowed "civilians" to purchase equipment just like the various military services and federal agencies procured. Vehicles, spent brass and a long shopping list of items were subsequently banned by executive order in the early days of Bill Clinton's Presidency.
Diesel-powered H1 Hummer is an excellent example. For twenty-five years after the executive order, civilian-owned diesel Hummers were scarce and always the most expensive. That's because civilian Hummers were all gasoline powered - except for the very few diesels that made it to civilian hands prior to the executive order. You may remember that used military diesel Hummers began passing the twenty-five year mark a year or so ago and immediately hit the civilian market.

 

[Job]

So

While **** Cheney was Secretary of Defense around 1989, he was responsible for changing defense procurement procedures to allow .mil purchase of less expensive "civilian" equivalents of various mil-spec items. The program has a name and I cannot remember it. This allowed "civilians" to purchase equipment just like the various military services and federal agencies procured. Vehicles, spent brass and a long shopping list of items were subsequently banned by executive order in the early days of Bill Clinton's Presidency.
Diesel-powered H1 Hummer is an excellent example. For twenty-five years after the executive order, civilian-owned diesel Hummers were scarce and always the most expensive. That's because civilian Hummers were all gasoline powered - except for the very few diesels that made it to civilian hands prior to the executive order. You may remember that used military diesel Hummers began passing the twenty-five year mark a year or so ago and immediately hit the civilian market.

It was only for the three years, and still I don’t think an exact military truck vehicle could be ordered. They don’t have ac, and are geared to go like 60 as a top cruising speed, so not many would want that. The topic vehicle here was from a fire dept cancelled order, not military.
A car with 400k can have anything wrong like the oil pump has to have some wear, so many areas. New oil might flow easier or thicker oil might strengthen the oil pump output, so many things other than an oil filter, which is really a screen placed in the main oil gallery to the engine. It wouldn't change flow by itself.

 

[Sierra977]

So

It was only for the three years, and still I don’t think an exact military truck vehicle could be ordered. They don’t have ac, and are geared to go like 60 as a top cruising speed, so not many would want that. The topic vehicle here was from a fire dept cancelled order, not military.
A car with 400k can have anything wrong like the oil pump has to have some wear, so many areas. New oil might flow easier or thicker oil might strengthen the oil pump output, so many things other than an oil filter, which is really a screen placed in the main oil gallery to the engine. It wouldn't change flow by itself.

You are misinformed. Mil-spec CUCV vehicles were used by various federal alphabet agencies like Secret Service, Marshals Service, IRS and many others. You may rest assured those vehicles were fully air-conditioned and optioned.
CUCV (Commercial Utility Cargo Vehicle) came in many configurations. Common military service designations like M-1008, M-1009, M-1028 and the like are common.

Commercial Utility Cargo Vehicle - Wikipedia

en.wikipedia.org

***AND I JUST REMEMBERED THE ACRONYM FOR CHENEY'S COST-REDUCTION PROGRAM!! IT WAS CALLED "COMMERCIAL-OFF-THE-SHELF" or COTS.*** It allowed military procurement of commercial grade vehicles (and many other things) in order to save money. Remember the $10,000 toilet seats? This resulted in vehicle manufacturers losing money on overpriced mil-spec vehicles. So what did the vehicle manufacturers do?? They immediately began offering all the mil-spec options on commercially available vehicles. And thus people like you and me could go to a dealer and option out a vehicle just like a formerly military ONLY mil-spec vehicle. That's what my truck is - a CUCV-spec fire department truck. Armored gas tank, high-ride suspension, thin door panels, heavy-duty electrical, heavy duty cooling, extra oil coolers and things I can only remember looking at the build list.

 

[Job]

Got it. I was t

You are misinformed. Mil-spec CUCV vehicles were used by various federal alphabet agencies like Secret Service, Marshals Service, IRS and many others. You may rest assured those vehicles were fully air-conditioned and optioned.
CUCV (Commercial Utility Cargo Vehicle) came in many configurations. Common military service designations like M-1008, M-1009, M-1028 and the like are common.

Commercial Utility Cargo Vehicle - Wikipedia

en.wikipedia.org

***AND I JUST REMEMBERED THE ACRONYM FOR CHENEY'S COST-REDUCTION PROGRAM!! IT WAS CALLED "COMMERCIAL-OFF-THE-SHELF" or COTS.*** It allowed military procurement of commercial grade vehicles (and many other things) in order to save money. Remember the $10,000 toilet seats? This resulted in vehicle manufacturers losing money on overpriced mil-spec vehicles. So what did the vehicle manufacturers do?? They immediately began offering all the mil-spec options on commercially available vehicles. And thus people like you and me could go to a dealer and option out a vehicle just like a formerly military ONLY mil-spec vehicle. That's what my truck is - a CUCV-spec fire department truck. Armored gas tank, high-ride suspension, thin door panels, heavy-duty electrical, heavy duty cooling, extra oil coolers and things I can only remember looking at the build list.

Got it. Was thinking strictly military vehicles. One reason for 10k toilet seats is the specifier. If a company has to to make a small number of parts with a very specific requirement no matter how small, the costs dramatically increase to produce the parts. The problem really is also the people making the orders not the manufacturer only. When the parts are made in volume the price goes way down. That’s what China does. I doubt if Bill in an EO was trying to spend more for parts, probably for a different reason. Let’s hope a P doesn’t spend time on a detail like that. Then one has to ask why B and C didn’t go back to the commercial vehicles can be ordered military spec when they had power? But that is gettingfarther into prohibited talk territory. In any case you had a lucky find that day. One factor besides the filter is the new oil. I think to isolate it to the filter one would have to go back to the old filter with the new oil, for just a minute, and see if it goes back to where it was on pressure, then back to the new filter again to confirm if pressure goes lower.