Which 5W-40 would you use....

[427Z06]

IMHO, I don't see a half quart every 3k miles as a consumption issue if you drive that thing hard. But if you want to experiment, I'd try Mobil 1 Extended Performance 10w30 for a couple OCIs and see what happens. If you're still not satisfied, try Mobil 1 Extended Performance 10w40 or RedLine 10w40 for the warmest 6 months (May-Oct). Drop back to the 10w30s for the coldest 6 months.

Oh, almost forgot, how about GC 0w30, it's more viscous than the Mobil 1 Extended Performance 10w30. I've found it in several AutoZones across Texas.

 

[427Z06]

quote:

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Originally posted by biodiesel00:
"I am going to stay away from the 5w-40 motor oil as it has the most non lubing viscosity modifiers."

Is that last sentence accurate? I think I need to do basic research on oil.

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With a quality synthetic, this generally isn't an issue to be concerned about. But keep in mind, the 5w40s are a substantial jump in viscosity at starting temps.

code:

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Kinematic Viscosity in cSt

T(C) Mobil 1 5w40 * Mobil 1 0W40 * GC 0W30 * Mobil 1 10W30

0° 1066 599.3 546.6 595.7

10° 523 327.6 291.8 298.3

20° 282 192.9 168.8 164.1

30° 164 121.0 104.4 97.6

40° 102.0 80.0 68.4 62.0

50° 67.1 55.4 47.0 41.6

60° 46.2 39.8 33.7 29.2

70° 33.2 29.7 25.0 21.4

80° 24.6 22.7 19.1 16.1

90° 18.9 17.8 15.0 12.5

100° 14.8 14.3 12.0 10.0

110° 11.9 11.7 9.8 8.1

120° 9.7 9.8 8.2 6.7

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[TooSlick]

Both a 10w30 and 5w-40 synthetic are going to give you excellent protection here. My recommendation is based on which grade is going to give you the best engine PERFORMANCE, fuel efficiency and the lowest oil temps. The pumping losses associated with running a high vis oil increase at high rpms - this is why Nextel engines now run 0w30 or even 0w-20 to maximize power output.

In a high mileage, worn engine, oil consumption would probably be marginally lower with the 5w-40. However if you use an xw-30 that is thick enough to be ACEA A3/B4 rated - HT/HS > 3.5 Cp - you'll have all the viscosity you need as well as the best performance. I've run 10w30 and 0w30 PAO/Ester synlubes in my 1.8L, 225 Hp, Audi TT turbo w/ 10,000 mile change intervals and they held up very well.

Please feel free to give me a call if you have more technical and/or applications questions. Phone # is listed on my Amsoil website.

TS

 

[427Z06]

quote:

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Originally posted by TooSlick:
However if you use an xw-30 that is thick enough to be ACEA A3/B4 rated - HT/HS > 3.5 Cp - you'll have all the viscosity you need as well as the best performance.

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Which is why many people like GC 0w30, RedLine Xw30, Mobil 1 0w40, and others.