M1 5W30 HM, 5400 miles on oil, '01 Suburban 8.1L

[Burbman]

Here is the report:

I could use some help interpreting the results...in the previous sample the oil was Valvoline 5W30 conventional non-synthetic. This report was Mobil 1 Hi-Mileage. What catches my eye is that calcium is way down, while Magnesium, Molybdenum, and zinc are up...are these changes a function of the composition of the oil or are they indicative of wear?

I was running a 3k OCI, and now 5K with synthetic, but based on the TBN I may run this oil till 7K. 160k miles on the truck now. All comments welcome.

Edit: I should also note that this oil was run with the Fram TG filter that I posted about in the other section.

 

[ThirdeYe]

Mobil 1 uses a lot of Zinc in their formulation, hence why it's only API SL rated. Looks good! How did it sound and perform? It seems like Mobil 1 is a bit noisier in my Scion when compared to the bulk oil the dealer had in it before. I didn't notice a difference in the Firebird, however.

 

[bigt61]

Stronger & different additive pkg - M1 HM vs VWB. Your #'s look great, especially since the M1 went 50% longer. 7k should be a piece of cake for your next M1 HM OCI. Even the VWB looks like it could have gone 5k w no sweat. Thanks for posting.

 

[Chris142]

The iron is higher than I would like to see. I personally would try a Dino oil,a 10w30 then a 10w40 to see if the iron comes down.

 

[Burbman]

Originally Posted By: Chris142
The iron is higher than I would like to see. I personally would try a Dino oil,a 10w30 then a 10w40 to see if the iron comes down.


The iron is lower now with the M1 that it was on the last UOA with dino oil....how will going back to dino lower the iron more?

Truck runs great and is a lot quieter on cold start with the M1....seems to have almost eliminated the dreaded "piston slap"...

 

[abycat]

Looks good to me. Before you make any judgement you need to look at the oils voa. Those engines are very powerful. I loaded a huge uhaul with all my stuff and an 18' boat behind it and that 8.1 didn't struggle at all. 1100km I drove in just over 9.5 hours. Only used about 400$ in gas. imagine a lower amount of boost, maybe 6psi under the hood. That would be awesome!

 

[sicko]

Here's what virgin/unused M1 HM looks like:
http://www.pqiamerica.com/June 2014/mobil1530a.htm

From that you can see that your Calcium, Zinc, and Moly levels are in line with the M1 HM additive package.

Your Magnesium did go up, but it's an additive in the regular M1 (http://www.pqiamerica.com/March2013PCMO/mobil1.htm), so I'd wager that it's just part of the M1 HM additive package at the time you bought it.

Overall your results look good. If I were you I'd continue to use a quality synthetic oil with 6k-7.5k mile oil changes depending on driving conditions (if you do a lot of towing, you want to lower the interval, if your driving is fairly easy then go on the higher side of the interval). Considering synthetic don't cost twice as much as convention oils, but you're running it for more than twice as long, it makes financial sense to keep using a quality synthetic oil.

 

[Burbman]

Good info, thanks! I tow a 32' RV that weighs about 8500 lbs with this truck. This oil sample only has a few hundred towing miles on it.

The truck has used 1 qt every 3k miles like clockwork since it was brand new. I always stuck to a 3k OCI so I never had to add any...now I have to add between changes. FYI, the GM standard for "excessive" oil consumption is more than 1 qt of oil to 100 gallons of gas. Since the truck gets 10 mpg, it would have to use more than 1 qt in 1000 miles.

 

[bigt61]

The iron #'s look fine. Those aren't exactly Honda Civic sized pistons going up and down, and there are 8 of them. My '92 7.4L has always used a little oil since new as well - about a quart every 5000. It saw many days of dragging a 12,000 lb trailer around in summer heat.

 

[Oil Changer]

Title says 5W report says 10W. Which is it? 5W is Al, 10W is A3 and heavier yet. Report reads like it's 5W.

 

[Burbman]

Good catch! Typo on the report, the oil used was 5W.

 

[Colt45ws]

Great report! I would say 7 even 9k would be no problem.

 

[spasm3]

All factory big block chevy engines i have been around, used a bit of oil. Even from new.
I think its the big pistons with bigger ring end gaps.