PP 5W30, 6,300 miles, 03 Silverado 2500HD 6.0L

[JohnVitamvas]

The last five oil analysis from my 2500HD Silverado. Engine is the LQ4 iron-block gas 6.0L V8. This truck is used almost exclusively for towing a racecar around the country, so lots of long highway slogs with a ~ 6,000lb load. It's a four speed auto with 4.11 gears, and it definitely turns some RPM. I have typically changed the oil when the dash indicator says it's time and analysis has yielded very consistent results.

I bought the truck with 100,000 miles on it and the original owner had the same usage as I do.. 90% towing. He used PP 5W30 so that's what I used except for one oil change when the parts store didn't have it in stock. Filters are Purolator Pure One.

Code:




Mi on Oil 6300 6000 6300 7400 7300

Mi on Unit 156300 150000 143990 137700 130300



Aluminum 3 4 4 4 4

Chromium 1 1 1 1 1

Iron 20 49 23 32 28

Copper 5 7 7 11 11

Lead 4 2 6 7 12

Tin 0 0 4 0 0

Molybdenum 51 55 57 57 56

Nickel 1 1 1 1 1

Manganese 0 1 1 1 1

Boron 10 1 2 3 4

Silicon 10 9 8 12 9

Sodium 14 5 3 5 5

Calcium 1989 2115 2452 2281 2203

Magnesium 9 9 10 8 12

Phosphorus 550 593 656 685 607

Zinc 636 726 786 793 754



Sus visc @210F 57.8 59.2 61.3 58.7 58.6

cSt Visc @100C 9.60 9.98 10.59 9.85 9.82

Flashpoint *F 415 420 405 400 445

Fuel %
Antifreeze % 0.0 0.0 0.0 0.0 0.0

Water % 0.0 0.0 0.0 0.0 0.0

Insolubles % 0.2 0.2 0.2 0.3 0.2

 

[krismoriah72]

Nice reports! curious to know what kind of mpg or gpm you are getting with that setup?

 

[4WD]

Looking at the one with 49 iron - anything remarkable about that OCI ?

 

[LeakySeals]

Any oil consumption replenishment during the interval?

 

[SwampSurvivor]

Random question - but is it still on the original transmission?

6300 miles seems pretty reasonable for such severe service.

 

[FZ1]

Looks really good. 4.10 gears turn a lot of rpms. viscosity looks good,6000 interval looks good,wear looks consistent. Stay with what you're doing.

 

[demarpaint]

It looks good. Just that one slight spike to 49 in the iron which doesn't really matter. For a tow rig, and a higher reeving engine due to the gearing it sure doesn't look like there's any negative impact.

People often equate higher revving engines to more wear, I'm not sure if that's the case though.

 

[JohnVitamvas]

Thank you for the comments.

Towing I average 11.2-11.4MPG staying around 75MPH. I've done a couple long highway slogs with no trailer and have seen as high as 13MPG. It's on its original transmission, which is a 4L80E. Pretty bulletproof transmission. Nothing special done to that, just fluid and filter changes every two years (~ 12,000 miles a year) and doing my best to keep the torque converter locked up.

It burns about 0.25qt per 6,000 miles. I don't know what happened on the one OCI with the high iron. Seemed like a random spike.

It is a great truck. Nothing fancy about it, but it was cheap and gets the job done.

 

[JoelB]

Are the 4.11 gears for towing benefits? I'm curious why you wouldn't opt for a more highway oriented rear gear to lower stress on the engine and maybe increase mpg.

 

[demarpaint]

Originally Posted By: JoelB
Are the 4.11 gears for towing benefits? I'm curious why you wouldn't opt for a more highway oriented rear gear to lower stress on the engine and maybe increase mpg.


Those 4.11 gears are putting less stress on the engine for and transmission for towing. They're not the greatest gears for fuel economy though.

 

[KL31]

I have 4.11 final drive on my 5 speed and [censored] it's [censored] for highway, I see about 3100rpm for 65mph ~ 110kmph. I wonder if there are transmission swaps you can do, that would have to be easier on the trans having short gears but more of them? Maybe a diff swap to 3.75? 6.0L V8 surely has enough power to cruise at a lower rpm? I suppose it is towing a lot of weight and probably weighs plenty to begin with.

 

[JohnVitamvas]

The 4.10s are standard on the 2500-3500 trucks. It's 4WD, so changing both front and rear R+Ps would be expensive and time consuming. 75MPH is about 2700RPM. It's a naturally aspirated gas engine, it has to turn some RPM to make power.

 

[4WD]

+1 ... Exactly ... Even my small truck has 4.11 ...

The O/D will settle the RPM down to some extent - but they are going to turn some RPM ...

 

[Ramblejam]

Originally Posted By: JoelB
Are the 4.11 gears for towing benefits? I'm curious why you wouldn't opt for a more highway oriented rear gear to lower stress on the engine and maybe increase mpg.

The 6.0L was only available with 4.10 in these trucks. The 8.1L offered both (3.73 & 4.10), where the Duramax came in only 3.73. In other trucks where you could choose (Suburban 2500, Silverado 2500), going to 4.10 gearing increases towing capacity by 20% (10k to 8k), all else being the same.

Even in brand-new trucks, it hasn't changed. 4.10 is only choice with 6.0 (3.73 is fleet only option, with GCWR dropping from 20k to 16k).

It's not as bad as the smaller LS engines (4.8, 5.3), but you still have to rev to make power; those who expect it to pull at low RPM's like a turbodiesel are not going to be pleased. On that same note, the 4L80-E is a robust transmission behind these engines, but there are only four widely-spaced gears available.

Originally Posted By: JohnVitamvas
it definitely turns some RPM

Still running the stock 245/75/16 tires?

Originally Posted By: JohnVitamvas
75MPH is about 2700RPM.

Really? 4.10 gears, 0.75 overdrive, and 30.47" tires have you at 2544RPM.

 

[JohnVitamvas]

Originally Posted By: Ramblejam
Originally Posted By: JohnVitamvas
it definitely turns some RPM

Still running the stock 245/75/16 tires?


Yes, Michelin LTX A/T 2 LT245/75/16

Originally Posted By: Ramblejam
Originally Posted By: JohnVitamvas
75MPH is about 2700RPM.

Really? 4.10 gears, 0.75 overdrive, and 30.47" tires have you at 2544RPM.


Michelin LTX A/T2s... tirerack.com shows that their revs per mile are 683 which is a more accurate rolling figure than the static diameter they list. This comes out to 2625RPM at 70MPH. But in reality they're half worn (55,000 miles on them). Subtracting half an inch from their overall diameter gives 2670RPM at 75MPH, which agrees with my GPS.

 

[johnD2]

Maybe I missed it...what filter are you using ?

 

[JohnVitamvas]

Generally whatever non-FRAM filter is on sale at the parts store. Last few changes have been Purolator Pure One filters, but there are some Wix filters in there, some AC Delco filters...

 

[johnD2]

Originally Posted By: JohnVitamvas
Generally whatever non-FRAM filter is on sale at the parts store. Last few changes have been Purolator Pure One filters, but there are some Wix filters in there, some AC Delco filters...


right on..thanks

 

[steve20]

thanks for the UOAs John--great info for me, especially. My son now has our hand me down 04 Tahoe--and I've cursed that 4.10 gearing for 12 years.
151K miles so far---with at least 125K of those punishing soccer-mom type driving. Burns a quart in 6K miles. OCI in the winter have been 3200 miles via the OLM so you can see the type of unintentional abuse this vehicle has seen
FWIW it turns 2250-2300 rpm at 70 mph using stock 17 inch tires---typically 15.6 mpg hwy--have seen as much as 17-18 on rare occasions (via trip computer)loaded or unloaded doesn't seem to influence mpg in a big way. Local MPg is between 11.5 - 12.5 mpg
We are currently wrestling with invisible coolant loss issues, and we do have the 706 heads so this is going to be a challenging decision--new heads & keep it, or Craigs List
Steve