Mixing weights?

[kballowe]

I've not been a fan of mixing different weights of different branded oils but the neighbor kid is short on cash and long on a variety or oil. Some nice person gave him a case of straight 40 weight and he's wanting to use it because it was free.

It's a early 90's Ford Ranger P/U with a 4-cylinder and 150,xxx miles.

I thought maybe he could mix a quart of the straight 40 with four quarts of 5W-20 and be OK?

Anyone?

 

[bepperb]

I wouldn't be worried about it causing harm, even just running the straight 40 weight. What I would be worried about is starting in the cold, especially if it has a weak battery.

If he has his heart set on using it now, yeah maybe a quart or two mixed with some 5-20. In the summer he could probably run it straight and be fine.

 

[Ibrahim]

agree with bepperb!

 

[Audi Junkie]

Sounds fine in your climate.

 

[94supraonchrome]

the kid could mix some MMO in with the 40 weight for winter starts.....

 

[wavinwayne]

If the kid is so short on cash that he can't afford an oil change, how can he afford to keep putting fuel in his truck?

That aside, I wouldn't run straight 40 weight oil this close to cool/cold weather. I would mix it with some cheap 5w20.

 

[kballowe]

Marvel Mystery Oil?

I dunno. It's a mystery.

Many moons ago in the days of old when I was a young man and dinosaurs roamed the earth.... worked at a cycle shop. Had a problem with about one in ten new bikes "locking up" about ten miles down the road. Tolerances too tight, they said. A nice salesman came in one day peddling MMO and had a good sales pitch. The boss bought some and we added a couple ounces to every tank of fuel for every new bike that went out the door. Never had another one "lock up".

It's good for something, I guess.

 

[kballowe]

Originally Posted By: wavinwayne
If the kid is so short on cash that he can't afford an oil change, how can he afford to keep putting fuel in his truck?


He doesn't - most of the time. He occasionally even brings me HIS definition of a "good used tire" and I mount it for him. The good thing is that he's always willing to help me out with just about any chore that I have going on.

HA - all four tires on that truck are different brands. Well at least they're the same size.

 

[gfh77665]

Originally Posted By: kballowe

I thought maybe he could mix a quart of the straight 40 with four quarts of 5W-20 and be OK?


I would mix two 40's with 3 5W-20's, and not even blink.

 

[kballowe]

Nobody cares that these are different brands of oil?

Have we arrived at the point that oil is oil and the brand really doesn't make any difference?

Many years ago - this was a no-no.

Of course - so was Pennzoil.

Times change.

 

[bepperb]

Well, it's a early 90's Ford Ranger P/U with a 4-cylinder and 150,xxx miles.

 

[kballowe]

Yeah - good point

 

[fdcg27]

I'd mix two quarts of the 40 with 5w30 for the colder months and I use it straight during the warmer ones.
Won't cause any harm, and a fresh forty beats anything left in too long.
I for one hate to waste anything, so I've been slowly using up a left over case of GTX 20W-50 by mixing with GTX 5W-20.

 

[Hoosier_Daddy]

something i've wondered is mixing viscosity pretty linear? meaning if i mix an oil with a cSt@100c of 10 with one of 20, is the resulting viscosity 15?

 

[crazyoildude]

spend the extra cash and put in the oil that your engine requires otherwise you will have to use the extra money u saved on the oil change to take the bus.... 40 wt in the upcomiong winter is an absolute no no.. 5w30-10w30 maybe a 10w40 at5 the most but not a strait 40 first of all if you are lucky enough to have your oil filter go into by pass and not explode how long id it going to take that oil to fully circulate..
i believe you have a 2.3 if im not mistaken a very good engine that likes the correct weight of oil

 

[jmac]

Originally Posted By: Hoosier_Daddy
something i've wondered is mixing viscosity pretty linear? meaning if i mix an oil with a cSt@100c of 10 with one of 20, is the resulting viscosity 15?


The mix is fairly linear in the logarithmic realm, I have to look up the formula again to make sure I get it correct but I did a simple program before for calculating the resulting viscosities of a mix of two oils, similar to this one, but basically it is the addition of the two oils percentage weighted in the log realm and take the antilog will give you close to the final viscosity.

 

[fdcg27]

That's how I've always figured it (percentage weighted), although FWIR, that does not actually give an accurate figure.
Still, I think it is probably a pretty good SWAG.
After all, the stated viscosity represents not a discrete value, but something falling within a range of values.

 

[Hoosier_Daddy]

yeah, i was figuring on a 6qt sump that ((5*oil a)+(oil b))/6 was somewhat accurate for a 5 to 1 blend