0W-20 vs 5W-30 vs 0W-30 in the 2024 Silverado ZR2 3.0L Duramax (LZ0): My Real-World Oil Analysis Results

Greg Nelson
1 hour ago
4 min read

What is the best oil for the 3.0 Duramax?

Based on multiple oil analysis samples from the same engine, both 5W-30 and 0W-30 perform well in the 3.0 Duramax. Wear metals remained controlled in both cases, with slightly different additive profiles depending on the oil brand. The decision often comes down to price, availability, and how the truck is used.

I’ve been running oil analysis on my 2024 Silverado 1500 ZR2 with the 3.0L Duramax diesel (LZ0 engine) since day one. I started with the factory-recommended Dexos D-approved 0W-20, then moved up to 5W-30 Pennzoil Euro L full synthetic for two changes, and finally switched to Mobil 1 0W-30 ESP for two more. I’ve got full Oil Analyzers Inc. reports for all of them, plus some older data from my previous Duramax truck. I use affiliate links in this article. If you buy through them, it helps support the content at no extra cost to you. Everything linked here is something I’ve personally run or would run in my own truck.

Full Video Here: https://youtu.be/AUoENYncMic

Today I’m breaking down the numbers side-by-side so you can see exactly what happened in my truck. This is not expert advice — I’m just a guy who sends samples and learns from guys like Lake Speed (huge shout-out to him — if you want to understand oil, watch his channel). I’m sharing real trends from ~4,900-mile intervals with the same PPE engine oil filter, 7-quart fills (no top-offs), and consistent driving.

The Oils I Tested

Sample 3: Mobil 1 0W-20 Dexos D (factory spec, great price at Walmart) https://amzn.to/491CT1B
Sample 5: Pennzoil Euro L 5W-30 (second fill with this oil, 4,866 miles, summer driving) https://amzn.to/4nisILW
Sample 7: Mobil 1 0W-30 ESP Formula (second fill with this oil, 4,900 miles, winter driving with daily remote starts + S&B oiled air filter installed) https://amzn.to/4watKxj

All samples ran with the PPE filter from demonworkshop.com Sample 7 was the only one with the oiled S&B intake.

Head-to-Head: Key Wear Metals & Contaminants

Iron (the big one — cylinder liners and rings)

Sample 5 (Pennzoil 5W-30): 36 ppm → 7.4 ppm per 1,000 miles
Sample 7 (Mobil 1 0W-30): 32 ppm → 6.53 ppm per 1,000 miles

That’s a 12% drop in iron wear with Mobil 1, even though it ran in winter with daily remote starts and extra idle time. Sample 3 (0W-20) showed noticeably higher iron — enough that I wanted to try thicker oil. The 30-weight oils clearly cut wear in my truck.

Aluminum

Sample 5: 3 ppm
Sample 7: 7–8 ppm (transcript noted 8)

Not concerning. Both are tiny numbers. Sample 3 was also a bit higher, so this seems more oil-chemistry related than actual wear. No trend that worries me, and iron stayed excellent.

Silicon (dirt/dust from air intake) Rock-solid and low across all samples. Even with the S&B oiled air filter on sample 7, there was zero spike. The filter is doing its job perfectly.

Soot

Sample 5: 0.5%
Sample 7: 0.6%

Extremely low in both. The tiny increase on #7 lines up with winter remote-start idling. Still basically perfect.

Fuel Dilution Minor on sample 7 (expected from extra idling), but well under safe limits. Viscosity held strong — no issues.

Additive Packages & Oil Condition

The oils use different additive strategies, which is totally normal.

Additive	Sample 5 (Pennzoil 5W-30)	Sample 7 (Mobil 1 0W-30)	Notes
Molybdenum (Mo)	4 ppm	77 ppm	Mobil 1 loads moly for friction reduction — great for timing chain & wet-belt components
Boron	63 ppm	189 ppm	Anti-wear & detergent; higher in Mobil 1
Calcium (detergent)	1,786 ppm	1,606 ppm	Neutralizes acids; both strong
Magnesium	39 ppm	12 ppm	Different detergent balance
Zinc (ZDDP)	851 ppm	893 ppm	Good anti-wear; both DPF-safe levels

Viscosity @ 100°C

0W-20 (sample 3): ~7.9 cSt
Both 30-weights: 11.3 cSt

The 30-weights stay in-grade and should handle high heat (towing in summer) better without shearing.

Base Number (TBN – D4739)

Sample 5: 4.11
Sample 7: 3.61

Still plenty of acid-neutralizing reserve left. Sample 7 used a bit more reserve due to winter idling/soot, but nothing alarming. I pulled the sample at the right time.

Nitration & Oxidation Both low and normal. No red flags.

Quick Note on My Previous Truck (2023 Silverado LZ0 Max Tow)

On my older Duramax I ran AC Delco 0W-20 for 7,700 miles (24k total on truck) and saw 42 ppm iron. But that truck had the PPE oil pan (+2 extra quarts) and PPE filter, so the iron was diluted across more oil volume. Stock pan numbers would have been higher. Still, the 30-weights in the new truck are beating it even with less total oil volume.

So… Which Oil Is Better?

Mobil 1 0W-30 (sample 7) performed slightly better in my truck.

Lower iron wear under tougher winter conditions, plus a much stronger moly package for the timing chain and valvetrain. Pennzoil 5W-30 was also excellent and produced very clean results. The 0W-20 did the job and kept the factory warranty happy, but I personally prefer the lower wear numbers I’m seeing with the 30-weights.

Both 5W-30 and 0W-30 gave me “no abnormal findings” from the lab and are safe to run. It really comes down to price, availability, and what you want — viscosity protection in heat or the absolute lowest wear numbers.

Right now I’ve got bottles of both sitting on the shelf, but I’ve already switched to Motul 5W-30 for the next test. I’ll be sending that sample in soon and will share the results.

Final Advice

If you want to stick with the owner’s manual, the Mobil 1 0W-20 Dexos D is an excellent, affordable choice. If you’re comfortable stepping up to a 30-weight and want to see lower iron, the Pennzoil 5W-30 or Mobil 1 0W-30 both work great in the LZ0.

Get your oil analyzed — especially if you’re deviating from spec. Trends over multiple samples tell the real story. I’ll keep testing 30-weights going forward because the data so far looks solid.

Thanks for reading (and watching the video). Drop your questions below — happy to discuss the numbers or future tests. And big thanks again to Lake Speed for all the oil knowledge I’ve picked up.

Stay tuned — more Duramax content coming soon.

— DemonWorks / DuramaxNews