MMO and oil pressure readings

[JohnBrowning]

How many people useing it have a real time reading oil pressure gage. If you gage does not move around significantly with RPM and even flutter at idle then you probably do not have a real time oil pressure gage. Most vechiles that have them are driven by the ECM/PCM epending on Make and as long as the oil pressure is in an acceptable range the needle stays put in the same place all the time. This is what most like me call idiot gages.....They only move if the reading is higher or lower then the average acceptable range as programed into the computer so they look like a real gage but function like an idiot light.

Like wise if you see no difference between a 15W40 and a 5W20 on the gage then it is not reading the signal at the sender and reporting it real time since these hot or cold should produce huge difference in behavior and reading.

No fast forward to MMO 1 quart of that stuff is going to thin the heck out of the oil. You have to expect an impact in hot and cold oilpressure as that is just the way things work no free ride. Now the question is how much is it affecting your application?

No idiot lights as thsestellus nothing unless your came on. Many of them are set so insanely low that it not comeing on would not be telling us much.

Anyone else have a Buick 3800 to try 1 quart of MMO in? Obviously you have to have a factory oil pressure gage to compare to my number's!

 

[PT1]

I doubt that most of the people on here who use MMO have even the slightest clue as to what it is doing to oil pressure. If they did the majority of them would stop using it. Same with Lucas "stabilizer" which probably sends Op readings off the chart.

 

[JHZR2]

I have a real time pressure gauge in my truck and in my MB diesels. I have never seen substantial differences between 30 and 40 wt oils, fwiw.

 

[mechanicx]

Are you getting this low oil pressure reading at you guage cluster or with an oil pressure tester T'd into the oil sending unit? I think before you throw MMO under the bus you should at least change your filter, then change the oil and see if the pressure reading improve.

I would doubt MMO would lower oil pressure that drastically. The way you make it sound is that it's straight solvent but it's supposedly also a lightweight oil. If MMO was just a straight solvent and lowered oil viscosity and oil pressure as much as you seem to be suggesting, then I wouldn't think they would recommend running that much of it for the entire oil run all these years. They would probably just tell you to run it until engine reaches warm up then drain it or something like that.

 

[Bob Woods]

There ain't much oil in it


Ingredient # 01
Ingredient Name BENZENE, 1,2-DICHLORO-
CAS Number 95501
Percent 0
Ingredient # 02
Ingredient Name MINERAL SPIRITS
CAS Number 8052413
Percent 0
Ingredient # 03
Ingredient Name NAPTHENIC HYDROCARBONS
CAS Number 64742525
Percent 0

 

[mechanicx]

I don't know for sure what MMO contains and at what percentages. I'm just saying if it was a straight solvent that lowered oil viscosity and pressure that much then why would they recommend up to 25% of it for the entire oil run all these years? And then state it will only lower visosity one grade. you'd think by now someone would have caught it lowering oil pressure too far if that was the case.

J_B has not proven anything yet. He seems like the type to throw an entire product or corporation under the bus based on half the facts like he does GM.

MMO could just as easily state run it until engine reaches operating temperature. So I'm skeptical.

 

[Trajan]

I ran a qt for 4,000 miles with no problem.

 

[severach]

I have a 1993 Buick Roadmaster with a Chevy 350 5.7L. The oil pressure gauge has a very fast response and ranges from redline 15 psi to max 60 psi. The oil light is somewhere less than 5 psi but doesn't work with this sender. The recommended oil is 5w-30. I've run two oil combos in the engine. The oil pressure is almost 60 psi when cold and once the oil warms up after about 20 minutes it can go as low as 20 psi at a red light.

5w-30 PYB + ARX for 2800 miles. Ambient 40*F-70*F. Pressure at high idle when cold is about 50 psi. Hot 75 mph 2100 rpm 40 psi. Red-light idle in drive at 525 rpm 20 psi.

10w-30 QS Dino + 1 quart MMO for 250 miles. Ambient 10*F-30*F. Pressure at high idle when cold is about 55 psi. When very cold it may start at 40 psi and rise to 55 psi as the oil warms. Hot 55 mph 1700 rpm 35 psi. Red-light idle in drive at 525 rpm 20 psi.

Other than the temperature and speed change the oil pressures are pretty much the same. Looks to me that MMO is thinning the oil by one grade as specified which I made up for by raising one grade.

My Delta 88 does not have an oil pressure gauge so no readings from the 3.8L. The 1998 Delta 88 coming off a 16,000 mile (242K-258K) OCI of Valvoline VWB 10w-30 plus makeup oil I changed to 4 quarts Mobil Delvac 1300 15w-40 + 1 quart MMO. No light.

 

[Familyguy]

I'm able to monitor my oil pressure in real time using a VAGcom on my jetta and I didn't see any appreciable difference in oil pressure (cold or warm) when I mixed 16oz with the remainder of my 4.5qts of oil being 5W-40 synthetic. I only ran the MMO for one OCI and now there isn't any in the crankcase so I've got a pretty good idea of what the numbers were post-MMO and (now) without MMO.

Best,

 

[Cmarti]

John has been pretty solid poster here. He put a quart of solvent/5 wt oil in and had a reduction in oil pressure. It was particularly significant in a 3.8 GM. None of this should be a shock to anyone, and should be a factor/data in your decisions on using solvents. (Lower pressure greater flow arguments aside)

I am leary to use solvents with 5W-20. I have used them short term before change (8 OZ Seafoam 500 miles), and I like to use with a heavier grade. I plan on trying MMO with a heavier grade in an older car. I use MMO in small engine fuel. So I am not an anti and This isn't an attack on MMO,..... just oil pressure is something to be considered.

 

[demarpaint]

What I've observed over the years is cold pressure is slightly lower and comes up faster with the addition of MMO. Red Light Idle is the same with or w/o MMO. I run 5W30 in this vehicle, IIRC it calls for 10W30 up to 50 grade depending on temps.

 

[Jimmy9190]

I recently added half a quart of MMO to my oil. I have been running 4 ounces to each 10 gallons of gas for a month now too.

My oil pressure is the same as it always was before using MMO in the oil, about 25 psi at a hot idle and right around 75 to 80 psi when going 75 to 80 mph at about 2100 RPM on the interstate. It might be a tad lower than it was prior to using MMO in the oil when I am driving in town and/or at slower RPM and speed.

When I added the MMO to the oil I was about 1100 miles shy of my next oil change and added it mainly for its cleaning benefits. It has helped my truck run better, idle smoother and quieter and made cold starts much faster and easier. This is on a 2001 Dodge Dakota with a V6 engine and 122K on the odometer.

I have had no adverse effects on my oil pressure from using MMO but I only added a pint. I get good quick oil pressure on cold starts too. I don't think any minor change MMO might have on oil pressure would cause me not to add MMO in the oil.

 

[ARB1977]

Ive got a Auto Meter gauge in my Tacoma with MMO and GC. Right around 75 psi cold...once warmed up alittle below 50 psi.

 

[demarpaint]

Sounds real good to me!

 

[mechtech2]

like others have posted, there will be a thinning of the oil with MMO used in it.
MMO is about a 5W. So it will thin any oil at operating temp.

This does not mean a death sentence, but we should consider our engine's needs and weather conditions if we use MMO in it.
Of course we should not overdose!