Rotella 5w-40 Synthetic, 9976 miles, Duramax

[wyandot]

Blackstone report for my '04 GMC Sierra w/6.6L Duramax.

Miles on oil: 9976
Miles on engine: 121,345
Oil Filter: Mobil 1 M1-303
Air Filter: AC Delco
Oil added: 1/2 quart

Aluminum: 2
Chromium: 1
Iron: 8
Copper: 2
Lead: 1
Tin: 1
Molybdenum: 3
Potassium: 5
Boron: 1
Silicon: 6
Calcium: 3042
Magnesium: 17
Phosphorus: 1072
Zinc: 1227
(All other values: 0)

SUS Visc @ 210: 75.1
Flashpoint: 395
Fuel %: 1.5
Insolubles %: 0.2
TBN: 9.8

I'm not real happy with the flashpoint & fuel %, but Blackstone's comments were: "1.5% of the sample was fuel (usually from idling/city driving) but it didn't hurt anything. Try 11,000 miles for the next sample. Great engine!"

I'm not a big fan of Rotella Synthetic, but it's hard to beat for a 5w-40 from a price/availability standpoint. And it certainly held up well this time. I have M1 T&SUV in the engine now, but will switch back to Delo in the spring.

 

[k1xv]

Wow, TBN was still almost 10 after almost 10K miles.

I also have a Duramax and have been using this oil. I only run it about 6500 or 7000 miles between changes. Glad to see it is doing so well in your Duramax.

You put on a lot of miles. I have an 03 Crew Cab Sierra with about 53000 miles. Next month, it will be on the road 3 years.

 

[Pablo]

What is the sump size and GM recommended normal OCI?

Looks like the oil did fine.

 

[The Critic]

quote:

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What is the sump size and GM recommended normal OCI?

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10 qt sump. No "set" OCI, all intervals are now based on the GM Oil Life Monitor, which extends to a maximum of 12500 miles/1-yr under ideal conditions.

GM has done away with the confusing maint. schedules, they've gone to a simple Maint. I and Maint II service, all calculated by the GM OLM. Honda has done the same, though the onboard MID shows a particular letter whenever service is due, indicating the service that is needed.

 

[wyandot]

I must admit, I was pleasantly surprised by how well the oil held up. On a previous 8k OCI with Rotella Syn, the TBN was 6.2 & wear metals were slightly higher, so I don't know why it's so much better now. It's been a very cold December here, so the engine has seen quite a bit of idling recently.

My owner's manual says to change the oil when the OLM reaches 0% or 10k/1 year, whichever comes first. The OLM was still reading 7% at 10k miles.

The truck will be 2 years old on Feb 5th.