Shearing - Add a Quart of 10w40?

[Nick1994]

I previously had a post about using 5w30 PP in my grandfather's 1996 Jeep Cherokee 4.0L with a Fram Ultra. There were many concerns over it shearing down a 5w30 and I have decided to replace 1-2 quarts of 5w30 in the future with 10w40. I have Castrol GTX SynBlend 5w30 in my stash as well as NextGen MaxLife 10w40 and Chevron Supreme HM 10w40.

He is somewhere around 1,600 miles in on the current OCI of 5w30 PP (6 quart sump). It gets its yearly oil change in November and I was wondering if I should now drain 1-2 quarts and refill with some 10w40? It's mostly short tripped but does get some freeway time every once in a while, maybe once a month. It sees 3-4,000 miles a year.

So what goes BITOG?

 

[GenesisGuy70]

Why not just run the 10w40 (or 10w30) all the time? Forget the 5w30 if you're concerned about shearing.

Seems to be easiest solution with no real downsides other than negligible decrease in MPG.

Your neck of the woods is warm.

 

[crazyoildude]

10w30 Pennzoil High Mileage is a great oil for the Jeep in the summertime

 

[WiskyBadger]

Just run the 10w40 all the time. Your in a warm climate and if it shears meh your just at a Xw30

 

[GatorJoe]

I wouldn't do a partial drain and fill with something from your current stash. I'd either run the full OCI with the current oil or drain all and refill with a 10w30 like QS Defy.

 

[Dallas69]

Don't worry about shearing.if you need to topoff any just use the 10-40 but I wouldn't drain any out.
You will be fine.

 

[Nick1994]

Originally Posted By: Dallas69
Don't worry about shearing.if you need to topoff any just use the 10-40 but I wouldn't drain any out.
You will be fine.
Unfortunately for this situation, it doesn't burn a drop lol.

 

[bigt61]

In Phoenix, I'd just run 10W-40 year round. But I wouldn't drain anything to add something different. Just use the 10W-40 as top off and stick with your yearly OCI.

 

[Merkava_4]

In a Jeep Inline 6 -- it should've all been 10W-40 from the get go.

 

[Shannow]

10w40 is one of my least favourite grades...for given oil, it's probably got more VII than the 5W30.

 

[ShotGun429]

("In a Jeep Inline 6 .... it should've all been 10W-40 from the get go.")

+1

 

[Merkava_4]

At least it still ends up being thicker than 5w30 -- although not by much.

 

[Chris142]

I don't see an issue with 5w30 in the jeep. That's what's in mine. How much does a quality oil such as pp shear anyway???

 

[Pontual]

In Arizona, a 10w40 "is the same" as 5w30 in Illinois. Not the same, but, you got my drift.

 

[bubbatime]

Um, Arizona, HELLO? Is anyone there? It gets like 120 degrees there in the summer. 5W30 is not the correct oil for your application. Those old, and I mean old, engines LOVE a 40 weight oil.

0W40, 5W40, 10W40, or 15W40 is what you should be running. I'd be inclined to run the cheapest 15W40 conventional I could find. It is a 20 year old Jeep after all.

 

[KzMitch]

Originally Posted By: Nick1994
Originally Posted By: Dallas69
Don't worry about shearing.if you need to topoff any just use the 10-40 but I wouldn't drain any out.
You will be fine.
Unfortunately for this situation, it doesn't burn a drop lol.


So it leaks?

 

[hpb]

Either drain it all out and swap to 10w40, or leave it be until November. I'm lazy, so I'd just be waiting until November and not losing any sleep over it...

 

[Nick1994]

Originally Posted By: KzMitch
Originally Posted By: Nick1994
Originally Posted By: Dallas69
Don't worry about shearing.if you need to topoff any just use the 10-40 but I wouldn't drain any out.
You will be fine.
Unfortunately for this situation, it doesn't burn a drop lol.


So it leaks?
Doesn't leak any measurable amount of oil. The level on the dipstick never moves. If you look underneath there's a drop of oil hanging off the oil pan though

 

[901Memphis]

I'd be using the 10w40 in Phoenix in that Jeep 4.0, but it would be Mobil 1 High Mileage 10W40.

 

[Nick1994]

I'll be changing the oil in the Jeep tomorrow with 5 quarts of Chevron Supreme HM 10w40 and 1 quart of Valvoline MaxLife 10w40, just to use up what's in my stash (only had 5 quarts of the Chevron, and 7 of the MaxLife in HM). I'll be reusing the Fram Ultra filter since it only has about 1,600 miles on it.

Thanks guys!