Making the switch to 5W40 from 5W30

Joined
Jul 2, 2017
Messages
54
Location
Tennessee
Ive read some articles that say a high mileage engine could benefit going to 5W40 from 5W30. This is a modular 4.6L 1999 Grand Marquis. Non PI engine like the 96-98 Mustangs basically.

The car has 165K on it. The car didn't have the greatest oil change history from my mother's ownership of it. I just want to do what I can to make it last as long as it can anyway that I can lol.

I'm in a mild winter environment. We have alot of 35-55 degree days through the winter. There might be 7 days out of the year where temps will even drop below 20. Obviously freezing days happen every once in a while.

I have a local advance going out of business and can snag a gallon of a few different brands for just $20 on the 5W40

I
 
Ive read some articles that say a high mileage engine could benefit going to 5W40 from 5W30. This is a modular 4.6L 1999 Grand Marquis. Non PI engine like the 96-98 Mustangs basically.

The car has 165K on it. The car didn't have the greatest oil change history from my mother's ownership of it. I just want to do what I can to make it last as long as it can anyway that I can lol.

I'm in a mild winter environment. We have alot of 35-55 degree days through the winter. There might be 7 days out of the year where temps will even drop below 20. Obviously freezing days happen every once in a while.

I have a local advance going out of business and can snag a gallon of a few different brands for just $20 on the 5W40

I
You'll be fine. High mileage, or not.
 
Ive read some articles that say a high mileage engine could benefit going to 5W40 from 5W30. This is a modular 4.6L 1999 Grand Marquis. Non PI engine like the 96-98 Mustangs basically.

The car has 165K on it. The car didn't have the greatest oil change history from my mother's ownership of it. I just want to do what I can to make it last as long as it can anyway that I can lol.

I'm in a mild winter environment. We have alot of 35-55 degree days through the winter. There might be 7 days out of the year where temps will even drop below 20. Obviously freezing days happen every once in a while.

I have a local advance going out of business and can snag a gallon of a few different brands for just $20 on the 5W40

I
What benefit are the articles claiming? I have two vehicles with 370,000+ miles from new, and I just use the appropriate spec 5w30 oils in each. BMW gets LL-01 or LL-04 and the Toyota just gets whatever 5w30 synthetic is on sale at the moment.
 
The 4.6L modular engine will go many hundreds of thousands of miles with just about any oil. The engine is very well made.

A synthetic 5w30 or 5W-40 will work amazingly well and with regular changes, a million miles is not out of the question. The million mile van, a 5.4L version of your engine used 10W-40 and lived for 1.3 million miles!
 
You can run anything in it, 20w-50 if you so wanted. 5w-40 is easy. I went straight to 0/5w-40 in my new vvt 2021 6.2 by the next year and I'm still under powertrain warranty. Got tired of 0w-20 getting burned. A simpler engine like that won't have any issue.
 
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