Oil Viscosity

Aug 8, 2021
I generally change engine oil myself. (If you want a job done right, do it yourself.)

I have an 11-year old Ford Focus with 127,000 miles on it. I’ve changed the oil 28 times so far, always with full synthetic.

The last time I tried to change the oil I couldn’t get the plug out, even with the longest wrench I had available. The most expedient solution was to take it to a quick-lube joint. I specifically picked one that offered Mobil-1.

I told them to use 4.5 quarts of Mobil-1 5W-20.

Two hours after I got home, I pulled the dipstick. The oil-pan was a bit over-filled. (I suspect they put in 5 quarts. Either that, or they didn’t let the pan fully drain.)

When I examined the paperwork, it said Mobil-1 0W-20, not 5W-20. I was furious. I called them and they said that they no longer carry 5W-20, and 0W-20 is an acceptable alternative. So I asked them why the owner’s manual doesn’t say that. They said it’s because 0W-20 didn’t exist when the car was built.

Even if they’re right, I don’t think they had any business deviating from my request without telling me.

What do you think? Will using 0W-20 potentially cause any problems?

(By the way, the last time I had an oil analysis at Blackstone Labs at around 100,000 miles, they said, “Whatever you’re doing, just keep doing it.”)
You're most certainly fine. Feel free to top off with some M1 5W-30 next if you feel better with that.
What exact M1 0W-20 and 5W-20 are we actually talking about?
It’s the newer equivalent so much ado about nothing. It’s not like your vehicle needed 0w20 and they put 15w40.

Straight from Mobil 1
I don't think you would notice any difference in the two.
i sure can't.....
Not defending the quick lube place but they didn't tell you any lies about the 0w20,
also your quote ( if you want a job done right do it yourself ).
who put the drain plug back in on the last oil change ?
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If anything, your service provider is staying current with what's happening in the lube industry AND you got a half quart of premium synthetic FREE. I would have kept my mouth shut AND brought them a dozen donuts instead, but that's me.
My daughter has a 2010 Focus I bought her new. I change the oil once a year using 5W-30 and use 5 qts.
You were furious over nothing. The two are essentially interchangeable. The overfill? No bueno if it's 1/2 a quart over.
I know you're right. But I've never heard a story of someone damaging their engine because they changed the oil too often.
But they do overuse resources and ruin the environment. Multiply this behavior by 250M and you'll see the point.

A 3k OCI will cause more engine wear. But, as usual, something else will likely kill the car - unless it is a Kia/Hyundi
0w-20 and 5w-20 are almost the same, 0w-20 even have a slight advantage in winter. However being a quick lube store they should tell you they ran out of 5w-20 and ask if you allow them to substitute with 0w-20. I will be upset if grocery story substitutes my order without any notice!

The real problem is the filter. Quick lube will cut cost on filter as much as they can. They are likely to use a very cheap filter w/o an anti drain-back valve, which would cause your engine running dry every time you start it. I'd suggest you do a short OCI for this oil and change it yourself with a quality filter next time.

Regarding to the oil plug, Try spray some penetrating oil around the bolt, wait for 10 minutes then lose it. I bought a Fumoto valve so I never need to remove oil plug to change oil in future.