I looked under the hood and 5-30 is the recommendation for the winter time. Would using 5-40 for the winter be overkill?
Is 5-40 too much when 5-30 is recommended?
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5w40 would be a little heavy IMHO for the wintertime, but there's no saying that you couldn't use it in the heat of summer with no issues.
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I say your engine will be fine - so will your climate be acceptable to it. Main reason is the 5W-40 are synthetics that flow easier than dinos of the same viscosity. When/if it falls below 5 degrees (rarely), let it idle for a couple of minutes before driving off.
i wouldnt bother with the heavier 5w40.. unless you burn oil like crazy or leaks. besides you want a thinner oil for cold startups up there in PA
GM says 5w40 where 5w30 is recommended may make the rings seize. Mazda, I donno.
Why is 5W40 too heavy {thick} when cold, when 5W30 is not too heavy when cold? Doesn't the 5W on each indicate they are the same thickness when cold?
Pour Point Valvoline Premium 5w30: -36C
Pour Point Valvoline Synpower 5W-40: -39C
Pour Point Valvoline Synpower 5W-40: -39C
I run RTS 5w40 in my 350 chevy winter plow truck without issues, but a car i'd stick with 5w30.
You are comparing different grades of oil, as well as different weights. Take Mobil 1 for example: Their regular and EP 10W30 pours down to 45 degrees. Their 10W30 M1 High Mileage oil pours down to 54 degrees. Point is, it doesn't matter what the pour point is; what matters is how thick it is at the temperature the winter pourability is checked.
You or your engine won't know the difference. Viscosity phobia here big time!
Heck too, the 5w40 will rob 50 HP.
If you don't get in line...we'll lock you away!...Sike!
Yes exactly! The point I was making is that I'm thinking the full synthetic 5W-40 will out flow the conventional 5w30. Disagree? Tell me why. . .
1999nick, not necessarily. Look at the 40 degree cST figure of the two different weights and you'll see that 30 weight is more free flowing than 40 weight at that temperature, and both will only get thicker as the temperature drops from there.
Sprintman, I love ya dude!!! Maybe you could send me some of your 25w70 for my Dodge Ram so that I can go racing on my Orange Belt!
Sprintman, I love ya dude!!! Maybe you could send me some of your 25w70 for my Dodge Ram so that I can go racing on my Orange Belt!
That's brings up this question: is flow directly related to cSt numbers at 40C?
I don't see the point of 5w30 synth. If you are buying synth, it's for viscometrics, get 5w-40.
usually the a 5w/20 is "thinner" than a 5w/30 is "thinner" than a 5w/40. Amsoil has easy to get at spec sheets to look at and compare.
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