Can I mix oil weights?

JMT

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I was going to change my oil today so I bought a 5qt of 10w-30 thinking I had a quart or two at home. Turns out I don’t. But I have several quarts of 5w-30. Can I throw one in with the 5 10w-30’s? I live way out in the country and I’m not going back to town
 
Idk if mixing them would be a problem, I would guess not.. but it would alter the viscosity.. I do know in cold climates the Jeep can run 5w30


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Absolutely ok and zero problem to mix them, all SAE motor oils are compatible with each other. You'll just end up with a 9W-30 by adding that quart of 5W-30 to 5 quarts of 10W-30. You can even mix conventional and synthetic motor oils together without issue.
 
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Thanks guys! 20 minutes later, done. 9W-30, the Xact TJ specifications anyway, right!?
 
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9.16W-30 to be exact. :D

It doesn't really work that way. One cannot simply average cold weather ratings because mixing does not change the cold weather rating in a linear fashion. However the math, while incorrect, does illustrate the concept that nothing bad will happen if one uses a quart or two that differs slightly from the manufacturer's recommended viscosity.

See, e.g., the discussion at: https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4676074/1

FYI - The 2006 Jeep Wrangler Owners Manual specifies 5W-30 for the 2.4 engine and 10W-30 for the 4.0 engine. However, the 2006 Factory Service Manual does not differentiate between the 2.4 and 4.0 engines but instead recommends 5W-30 for both engines for ambient temperatures from -20*F up to 100*F and 10W-30 for both engines for ambient temperatures from 0*F to 100+*F..

Bottom line: Unless you live in an extreme climate you can use all 5W-30 or all 10W-30 or any combination of the two.
 
It doesn't really work that way. One cannot simply average cold weather ratings because mixing does not change the cold weather rating in a linear fashion. However the math, while incorrect, does illustrate the concept that nothing bad will happen if one uses a quart or two that differs slightly from the manufacturer's recommended viscosity.

See, e.g., the discussion at: https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4676074/1

FYI - The 2006 Jeep Wrangler Owners Manual specifies 5W-30 for the 2.4 engine and 10W-30 for the 4.0 engine. However, the 2006 Factory Service Manual does not differentiate between the 2.4 and 4.0 engines but instead recommends 5W-30 for both engines for ambient temperatures from -20*F up to 100*F and 10W-30 for both engines for ambient temperatures from 0*F to 100+*F..

Bottom line: Unless you live in an extreme climate you can use all 5W-30 or all 10W-30 or any combination of the two.
and your point is?
 
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TJ2 said:
and your point is?

1. Averaging oil viscosity numbers does not provide an accurate or particularly meaningful result; and

2. In response to the original query and as stated above:

The 2006 Jeep Wrangler Owners Manual specifies 5W-30 for the 2.4 engine and 10W-30 for the 4.0 engine. However, the 2006 Factory Service Manual does not differentiate between the 2.4 and 4.0 engines but instead recommends 5W-30 for both engines for ambient temperatures from -20*F up to 100*F and 10W-30 for both engines for ambient temperatures from 0*F to 100+*F..

Bottom line: Unless you live in an extreme climate you can use all 5W-30 or all 10W-30 or any combination of the two.
 
Between my girls, wife included and a few out dated vehicles in the driveway I change oil in 6 cars.
Sometimes I simply dump everything I have together to sneak in an oil change.....but never the TJ. Lol
 
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As a follow up, has anyone had an oil filter that was cross-threaded out of the box? I had one today, tried several times to thread it and could never get it. So I grabbed another, fortunately I had one on hand, and it threaded perfectly. I’m going to call the company.
 
As a follow up, has anyone had an oil filter that was cross-threaded out of the box? I had one today, tried several times to thread it and could never get it. So I grabbed another, fortunately I had one on hand, and it threaded perfectly. I’m going to call the company.
Please drink after you changed oil.
 
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