oil question (10W-30 or 10W-40?)

[MustangGT]

I think I would like to avoid putting 5W-30 in this particular car, it starts fine right now using 10W-40 and it's in the 20 degree range here in eastern Washington state. Maybe I'll try 10W-30 next time.

 

[palmerwmd]

A 10w-30 will not give you an improvemnt in cold start over a 10w-40. It is the first number in a viscosity rating that indicates cold start ability. And both are a 10w-. So if you want improved cold start a 10w-30 will not give it to you, but a 5w-30 will. (Of course if you were running a full synthetic oil you could stay with a 10w40 even thru the winter.) Fred...

 

[dragboat]

quote:

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Originally posted by MustangGT: I think I would like to avoid putting 5W-30 in this particular car, it starts fine right now using 10W-40 and it's in the 20 degree range here in eastern Washington state. Maybe I'll try 10W-30 next time.

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I agree on staying away from the 5/30 if possible. Look at some of the data sheets at the various company sites,some 10/30's pump easier when cold than others. Actually some pump as well as some 5/30's,,just have to cruise the sites and print the data.

 

[MolaKule]

One could, theoretically, get a slight cold temperature pumping advantage with a 10W30. In addition, you would have less VII's to shear back and thicken the oil.

 

[palmerwmd]

I agree that generally a 10w-30 is a allround better grade (due to less VI's used), and also that some 10w-30's exist, that pump better cold than some 5w-30's, (I didnt wanna complicate my original reply). But in general for winter drving most 5w-30's will pump better cold than most 10w-30's. Fred...

 

[MustangGT]

In an older economy car that recommends 10W-30 or 10W-40 year round which is the better choice during the winter? The car is a mirage with 158,000 miles on it. I've been using 10W-40 all summer, but noticed that 10W-30 can used pretty much anytime of the year too.

 

[palmerwmd]

If you dont use synthetic oils, I would recommend 5w-30 in the winter while staying at 10w-40 in the summer. Fred...

 

[csandste]

I agree with Palmerwmd. In most cases a 10W30 is a better all around oil than a 10W40 IMHO. Dependig on the severity of the winter, you could move to a 5W30, but wonder about the thinness of the oil in a car that old.

 

[dragboat]

Quote: 'Dependig on the severity of the winter, you could move to a 5W30, but wonder about the thinness of the oil in a car that old." If very very cold no problem,that oil will be pretty thick I believe even when driving for short distance because of oil temp. Take some 5/30 dino and get it to 20F somehow and pour it into a container,glug glug,