What weight oil to add when down a quart?

[BlueOvalFitter]

What if you had an engine that held 6 qts. of oil. Then, what if you came across the last 5 qts. of 5W30 PU for a super low price and had to choose between a qt. of 5W20 or 10W30 PU to make the 6th qt. Which one would you choose, the 5W20 or the 10W30?

 

[gfh77665]

10-30 for sure. All oils will shear some over time, and the 10-30 would buffer that effect just a bit.

 

[Patman]

I would see if a nice member of BITOG would be willing to part with one of their extra quarts of 5w30

 

[CharBaby]

Super Low Price?
I buy the shelf of all the oils in those weights!

 

[KD0AXS]

Depends what said engine calls for. In the case of your F-150 that probably calls for 5W-20 anyway, I'd go with the 5W-20. If the engine calls for a 30, then I'd probably go with the 10W-30.

Or....find another WM that has more 5W-30.

 

[TallPaul]

Originally Posted By: gfh77665
10-30 for sure. All oils will shear some over time, and the 10-30 would buffer that effect just a bit.

5w20 may be as sheer stable if not moreso than 10w30. But assuming the car calls for a 30 weight I would be inclined to add the 10w30 as the 6th quart.

 

[05LGTLtd]

This conundrum has obviously bought strife and confusion to your life. Either one you choose, you will be awake nights wondering if you have chosen the correct substitute. As stated here numerous times on BITOG, it is not our place to play tribologist. Besides the fact that they were willing to sell you 5qts of Ultra for so little in the first place means you probably received an inferior product. I mean there's got to be a reason they have stopped selling this stuff almost everywhere. Simply give the 5qts to someone with a smaller sump. You need to rid yourself of this wretched monkey's paw before its to late...

(10w-30)

 

[earlyre]

I have a lone qt of Castrol Syntec(SM) 5w30 that i picke up for around 90 cents.if you wee closer to me i'd let you have it..unless you think mixing brands might cause your engine to explode...

 

[SwampSurvivor]

I would buy a 6th quart of something cheap in the same grade.

Before I switched to Rotella in the Cherokee (gallons only), I would buy a 5 quart jug of 5w-30 synthetic, then get a quart of ST synthetic or ST dino (depending on how I was feeling) for that 6th quart.

 

[dparm]

For top-off I would suggest something slightly thicker than normal. Oils thin-out in service and adding something thick should help bring it back within spec, though your car's manufacturer of course knows that oil thins out and engineers things to still work despite that.

 

[ARCOgraphite]

King Solomon style:
1/2Qt 5w20 and 1/2Qt 10w30

 

[qweased123]

Forget all this antiquated measuring and add a litre instead.

 

[05LGTLtd]

Originally Posted By: qweased123
Forget all this antiquated measuring and add a litre instead.


You can't mix liters and quarts, your engine will blow up!

 

[TFB1]

Originally Posted By: qweased123
Forget all this antiquated measuring and add a litre instead.


A whut??? Oh that's right, you ain't from around here...

 

[Brit33]

yep a thicker oil is what I'd add.
Just did the same. mine requires 50wt oil. about 4.2 litres.
added just about 150ml of 60wt oil in the 4 litres of 15w50 I had.

I'll use this as a top up when it burns oil also.

 

[BlueOvalFitter]

Originally Posted By: Brit33
yep a thicker oil is what I'd add.
Just did the same. mine requires 50wt oil. about 4.2 litres.
added just about 150ml of 60wt oil in the 4 litres of 15w50 I had.

I'll use this as a top up when it burns oil also.


Say what?

 

[gfh77665]

Originally Posted By: TallPaul
Originally Posted By: gfh77665
10-30 for sure. All oils will shear some over time, and the 10-30 would buffer that effect just a bit.

5w20 may be as sheer stable if not moreso than 10w30. But assuming the car calls for a 30 weight I would be inclined to add the 10w30 as the 6th quart.


Even if the 5-20 is shear stabil, its a 20wt, not a 30wt. The 10-30 would help the 5-30 remain more like a 5-30, while a 5-20 would bump it in the direction of a 20, where it would likely shear down to with time. So, a 5-20 would, in essence, accelerate the shearing. The 10-30 bumps it in the other, correct direction, to combat shearing.

 

[Brit33]

Originally Posted By: BlueOvalFitter
Originally Posted By: Brit33
yep a thicker oil is what I'd add.
Just did the same. mine requires 50wt oil. about 4.2 litres.
added just about 150ml of 60wt oil in the 4 litres of 15w50 I had.

I'll use this as a top up when it burns oil also.


Say what?

in other words go for the 30wt

 

[BlueOvalFitter]

Originally Posted By: Brit33
Originally Posted By: BlueOvalFitter
Originally Posted By: Brit33
yep a thicker oil is what I'd add.
Just did the same. mine requires 50wt oil. about 4.2 litres.
added just about 150ml of 60wt oil in the 4 litres of 15w50 I had.

I'll use this as a top up when it burns oil also.


Say what?

in other words go for the 30wt

Oh, ok.

 

[BlueOvalFitter]

Originally Posted By: BlueOvalFitter
What if you had an engine that held 6 qts. of oil. Then, what if you came across the last 5 qts. of 5W30 PU for a super low price and had to choose between a qt. of 5W20 or 10W30 PU to make the 6th qt. Which one would you choose, the 5W20 or the 10W30?

If you notice in my OP it was altered to make it an easier thread to be searched, which I don't mind at all.
But, stay tuned to this thread; it will get better tomorrow!

To be continued...............