Don't mix oils! Oil pressure dropped ---

My lowly 2012 Transit Connect lived its life on frankenbrews of leftovers from my Audis and VWs and was well over 200k miles when I sold it. It had the basic 2.0 Duratec engine and saw 200 to 400 miles a day fully loaded with mostly highway miles to get to very remote rough last mile destinations. It never used oil and typically saw 7,500 to 10k oci.
I never thought about incompatibility of mixing oils like I did, but it was always pretty much top end euro oils that the VAG engines required ranging from VW 502, 504 and 508 specs so I doubt there would be much incompatibility among them.
 
Unless one ran the same exact oil from the day the factory fill was dumped there’s always residual from the previous fill and no pouring that leftover quart through from the last oil change isn’t changing molecular chemistry lol. So unless we’re religious and brand loyal there’s a little bit of a Franken-Brew in all of us. I’m guilty there I go from Kirkland - Supertech - Mobil 1 - Castrol - Pennzoil - NAPA full synthetic. Even a Qt of O’Reilly house brew synthetic when I was a Qt shy for an oil change.
 
DCDG said:
Unless one ran the same exact oil from the day the factory fill was dumped there’s always residual from the previous fill and no pouring that leftover quart through from the last oil change isn’t changing molecular chemistry lol. So unless we’re religious and brand loyal there’s a little bit of a Franken-Brew in all of us. I’m guilty there I go from Kirkland - Supertech - Mobil 1 - Castrol - Pennzoil - NAPA full synthetic. Even a Qt of O’Reilly house brew synthetic when I was a Qt shy for an oil change.
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While that is technically true, once you have run the same oil for 4 or 5 intervals in a row there’s probably only 1 or 2% residual left of the different oil that was in there before. So it’s really not a Frankenstein-Brew at all.
 
70GS455 said:
I used 3 qts Mobil 1 Euro 0W40 and 3 qts Quaker State All Mileage 5W30 with Microguard Select VAFI filter. We noticed the oil pressure would drop a few psi over a certain rpm range, and got worse with higher oil temps.
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I did some studies with Nissan about 10 years ago where they had problems small engine SUV's a Pickups driving several times a week up and down the mountains from 600 ft above sea level to 12,000 ft before coming down to the city at 8500 ft. These were driven at high rpm for extended periods of time and built high temps on the climbs.

The result was high shear, with pressure loss and high consumption, going through two liters per trip. I put a good PAO in them and eliminated the problem.
(as a side note, I had a group II oil in my Mini (with automatic transmission in the sump), and a skid plate. Temps my first drive here in Florida was in 90º weather, and the oil temp hit 140ºC (284ºF). I took off the skid plate and temps came down to 90s (ºC), but oil pressure did not come back until I changed the oil.)

So I suggest that the problem is not the mix, but that one of the two had not-so-great polymers.
 
dbias said:
My lowly 2012 Transit Connect lived its life on frankenbrews of leftovers from my Audis and VWs and was well over 200k miles when I sold it. It had the basic 2.0 Duratec engine and saw 200 to 400 miles a day fully loaded with mostly highway miles to get to very remote rough last mile destinations. It never used oil and typically saw 7,500 to 10k oci.
I never thought about incompatibility of mixing oils like I did, but it was always pretty much top end euro oils that the VAG engines required ranging from VW 502, 504 and 508 specs so I doubt there would be much incompatibility among them.
Click to expand...
Probably a combination of very ideal usage (highway miles) and using very high quality oils. Hard to beat VW 502 and 504.
 
I just mixed 1.5 qt.s of Pennzoil platinum Euro with the rest of my Castrol Edge Euro (both 0w40). I plan on going back to Pennzoil Ultra Platinum and will probably mix in a little of the Platinum to top off on the next couple changes. I change every 4k with filter since I have 2500 HD and use it as a truck!
 
OVERKILL said:
I use leftovers for the mower or pressure washer or something that the sump is small enough that not a lot is needed. If it's a really small amount, I'll use it for a GP lube.

My compressor has Mobil 1 0W-40 in it, my push mower currently has Mobil 1 0W-40 in it and my pressure washer has Redline 5W-30 in it I think? My generator has Pennzoil Ultra Euro 5W-40 in it. The Redline and Pennzoil were both spare quarts I had kicking around, so if you've got OPE, that would be a good use for that 5W-40.
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My compressor has HPL recip life. My mower and PW get VR1 20w-50 synthetic.
 
kschachn said:
It’s a miracle.
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Appreciate the answer. But the oil pan is a 6 quart pan. I added a full-length close-fitting louvered windage screen. I had 6 quarts in it, the required amount. I was not expecting to have to drain oil out.
 
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