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Oil change

While changing the oil in my '07 Lincoln MKX, i realized I had put in 1.5 quarts of 20W-50 oil rather than the recommended 5W-30. Should I drain the oil or is that amount not enough to worry about?

No. 20W50 isn’t really thick. Yes. Oil is the cheapest thing to fix.

I would drain the oil and replace it with 5W-30. This would be very cheap insurance.

You can save the drained 20W-50 and use it for something else.

1.5 qts of the 20W and how much of the 5W? Assuming 3.5 of the 5W I leave it alone if you live in most of the US now. If you live in Alaska, or Int. Falls, MN or some other place where night temps are in the teens or below; in that case I’d change it.

You have something close to 7W in there now and that should be fine as long as cold temps aren’t “extreme”.

That’s pretty much it. Had drained the oil, changed filter and put in appox 3.5qts. 5W-20. I the grabbed another jug, began pouring and realized it was 20W-50. Had put in only about 1.5 qts. Problem was I did this right before I had to leave and couldn’t spare the time. So I gambled and drove appox. 200 miles already. If there was damage to be done, I guess it’s done.

Thanks for all responses

Why do you have 20W50 around? I used that oil in my car living in the tropics near the equator, where the overnight temperature was an average of 77F, and daytime highs were always in the 90s.

Part of the process of the oil breaking down over time is that it thickens up some, as well as a host of other things. Since in this case, you are only dealing with the thickening up part, I’d say you did less damage than if you had not changed the oil at all, so that would be virtually no damage.

But, I would suggest another oil change at the earliest opportunity. A back to back oil change once in a while will help keep your engine cleaner, so you can turn this into a good thing.

I would definitely drain and replace the oil with the proper weight. Why risk your engine to save a few bucks? 20w-50 is much different than the standard weight.

For the motorcycle; classic case of hurrying and not paying attention.

Thanks for all responses. It comes down to not being lazy and just drain & replace. Thanks again.

You’re exactly right; just get off my rear and do it.

Here in rural Puebla, Mexico, they mostly sell 20W-50 in the stores and parts places. It really doesn’t get that hot here. Not nearly as hot as in McAllen, Texas. I have no idea what cultural error prompts this, but if you search you can sometimes find 5W-30.

Drain it and refill with the recommended oil.

First of all, 20W is much more viscous than 5 weight. Secondly, 20W-50 is achieved by adding a high amount of “viscosity modifiers”. Viscosity modifiers are actually coiled microscopic polymers that uncoil when heated and expand, increasing the viscosity of the warm oil. The modifiers themselves do not have as good a lubricatting properties as the base oil. A spread of 30 in the base weight compared to the “modified” weight is really the top level of what’s considered acceptable spread to still maintain good lubricatting properties with the mix. 20W-50 is at that top acceptable level.

So, between the higher base weight and the large level of viscosity modifiers, if it were mine I’d sleep better changing it out for the proper oil. It’s way too easy to correct this error completely than to lose sleep worrying about your compromise.

Thanks for the response. Pretty much what would make sense; why keep thinking about when a simple oil change takes all of 15 minutes. Thanks again.