Should I add a quart of Mobile 1 to my sump?

[SteveD2]

My Cherokee's 4.0 engine has almost 200,000 miles on it with synthetic oil. (from the previous owner) Right now I'm running about 5.5 quarts of Chevron 10w40 and 1 quart of Havoline synthetic 10w30 that's been in there about 400 miles. (I'm too cheap for full synthetic

)

On to my question...

I have a quart of Mobile 1 5w30 sitting on the shelf, I don't think I'll be using it for anything. Should I add it to my sump? I think I might get a UOA at around 3k on this mixture...

 

[KW]

It most likely would not hurt anything but I would save the M1 5W30 for the lawn mower and not mix the oil.

 

[Lubricious]

I say to save it for next winter when your using all 5W-30 oil.
You've got mostly 10W-40 now, why dilute this viscosity?
BTW---why are you using 10W-40 in Oregon in February anyway? Isn't it really cold weather there now?

 

[SteveD2]

quote:

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Originally posted by Lubricious:
I say to save it for next winter when your using all 5W-30 oil.
You've got mostly 10W-40 now, why dilute this viscosity?
BTW---why are you using 10W-40 in Oregon in February anyway? Isn't it really cold weather there now?

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I thought it would be best for this engine having almost 200,000 miles on it. There are lots of people that run 15w40 or 20w50 year round. Usually it doesn't get below the upper 30's at night here, and the days are in the 50's. Also it's kept in a ~60 degree garage.

 

[therion]

I think you are much better off going with a premium synthetic blend like Schaeffers 15W-40, they are inexpensive and are a proven formula. A good HDEO blend will provide great protection year round especially if you don't see temps below 30*.