5w30 vs 10w30

[Arctic388]

which grade ?
5w30 or 10W30 ?

all my vehicles call for 5W30 but comparing 5-10 the 10's specs look just a little better. synthetic of course. so which to use ? the temps in my area are 98 right now and heat index of 108 boy it hot. but in the winter it might get to 15 degrees for 2 days. it usually snows twice a year and that is measured in hours not days. so both being good oil is there any reaso to use 5 over 10 ? any better fuel mileage ?

thanks

 

[TallPaul]

I would run the 10w30 in your area. In fact I run 10w30 and 10w40 in all three vehicles here in Detroit.

 

[Big Jim]

I would use the 5W30 that the manufacture calls for unless you had a compelling reason not to. It still behaves better at startup, even if it doesn't get very cold.

 

[Tones]

My personal opinion is that most synthetic 5W-30s do not have the same tendency to shear as dino 5W-30s. As long as your vehicle is not too hard on oil, I see no reason not to use the 5W-30 year round. The 5W-30 would give you slightly better gas mileage until the engine warms up.

 

[Ugly3]

No oil is thin enough at startup, 5w30 all the way!

 

[Arctic388]

so am i right in saying that if an oil "shears" it gets thinner ? say 5w20 or so. strangely i want that.

so if that is right does that mean i might have more oil "consumption" ? neither of my vehicles uses a 1/4 quart over 5-6K miles and that is on Havoline 10w30 Dino oil. the thing is i actually "want" some consuption cause i'll be switching to synthetic and extending my OCI so i want to have to add some so as to build it back up.

does any of this make since to anyone but me ?

 

[Ugly3]

A good synthetic will go 10,000 miles without any help. Go for it!

 

[Buick92]

Use 10w-30 except for winter then switch back to 5w-30, you'll find that many members here do that.

 

[Blake Sobiloff]

quote:

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Originally posted by Arctic388:
so am i right in saying that if an oil "shears" it gets thinner ? say 5w20 or so. strangely i want that.

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Yes, shearing of an oil means that it becomes thinner at operating temp. For example, your 30-weight oil could shear down to a 20-weight oil. It doesn't always happen, though; some oils thicken the longer they are used.

quote:

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so if that is right does that mean i might have more oil "consumption" ?

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Possibly. It will depend on the state of your engine and your operating environment. There are so many variables it is nearly impossible to predict with certainty. Your best option is to keep records for yourself (UOAs, MPG, etc.).

 

[Arctic388]

thanks all.