5.3 vs 3.0 longevity

[ryanm33]

I am looking at upgrading my 2015 Silverado 5.3l with 190,000 km’s(118,000 miles) without any issues . I have come across 2 trucks that I am interested in. A 2025 elevation with the 3.0 Duramax, with 20,000 km(12,500 miles) and a 2024 elevation with 10,000 km(6000 miles). I see lots of posts praising the better fuel efficiency of the 3.0, but what about longevity? I keep my vehicles for 10-12 years and average 200,000kms. I know the 5.3 is tried and true, but has some lifter issues. Will the Duramax last me 10-12 years? I am fairly meticulous with routine maintenance ( oil changes, transmission fluid changes). Any input on the longevity of these engines would be appreciated.  
 

I drive about  20,000 km per year. About 50/50 city/ highway, my daily commute to work is 25 km( 15 miles) each way. 

Edited August 21, 2025 by ryanm33

[redwngr]

We don't know.

There haven't been building 3.0's for that many years yet.

(and the 5.3 ishad changes less than 10 years ago too) 

 

The earlier LM2's had the oil bump belt changed scheduled for 150,000 miles (240,000 km)

The from 2023 to current, the 3.0 is an LZO with belt replacement scheduled for 200,000 miles (When you 3.0 gets to 200,000 miles, (320,000 km)

 

I'd say (124,000 miles) 200,000 km is a pretty safe bet.  

 

 

There are some that have already had a belt change.

 

 

Edited August 21, 2025 by redwngr

[PunchT37]

I believe less parts is more reliable.

[Atlas]

Fewer parts? The 3.0 has 2 fewer cylinders, one less head, 8 fewer spark plugs, only one exhaust manifold instead of two, and doesn't have DFM garbage 

 

The LZ0 Duramax has a fully forged crank, steel pistons. It's built very well, but it's also subjected to higher pressures than a 5.3. All the makings of a long lasting small diesel are there...but time will tell.

[ryanm33]

What about reliability of the emissions system?

[PunchT37]

I stand by my statement. For all machines.

 

Back to the 3.0 vs 5.3. Pull the engines and put em on a stand and see the parts difference. Pull the rear cover and valve cover off the 3.0. Not to mention the coolant controls and added turbo parts.

[Z45]

Longevity is a function of individual ownership of the vehicle.  Some can get many years of useful life while others can make it junk in a few years.  

Edited August 22, 2025 by Z45

[PunchT37]

20 minutes ago, Z45 said:

Longevity is a function of individual ownership of the vehicle.  Some can get many years of useful life while others can make it junk in a few years.  

True dat. But, complexity with lack of maintenance means doom comes quicker.

[PunchT37]

13 hours ago, Atlas said:

Fewer parts? The 3.0 has 2 fewer cylinders, one less head, 8 fewer spark plugs, only one exhaust manifold instead of two, and doesn't have DFM garbage 

 

The LZ0 Duramax has a fully forged crank, steel pistons. It's built very well, but it's also subjected to higher pressures than a 5.3. All the makings of a long lasting small diesel are there...but time will tell.

I wouldn’t use a forged crank as a qualifier. How bout the 5.3 vs the 6.2?

 

Yeah, I know forged is tougher than cast, but…

[Atlas]

7 hours ago, ryanm33 said:

What about reliability of the emissions system?

 

Loaded question. You'll soon get all kinds of responses about how emissions have ruined modern diesels and it's all a problematic, unreliable nightmare AND its a government conspiracy designed to cost the consumer money. All while George Soros rides around in a jet and a farmer with a diesel tractor is put out of business because of DEF issues.

 

Most of the evidence is anecdotal and spiteful. My anecdotal evidence, having owned a few different modern diesels, is I've never had an issue. Whether by luck or just good maintenance, I've not had problems with SCR systems, EGR's or anything else. But I also don't modify my diesels or do things which cause issues like letting DEF go bad over seasons of no engine use, or using various fuel additives when the manufacturers say specifically don't do that. The reality few people talk about is the trucking industry and the billions of miles driven with SCR systems operational. For the most part people don't have problems, but it's certain you will hear about it when someone does. That provides a skew in both anecdotal evidence, and on forums, etc.

[Atlas]

3 hours ago, PunchT37 said:

I wouldn’t use a forged crank as a qualifier. How bout the 5.3 vs the 6.2?

 

Yeah, I know forged is tougher than cast, but…

 

Manufacturing defect

[Jus Cruisin]

So my 3.0l lasted exactly 5,403 miles. Engine siezed. Waiting for a replacement. No warning. Just a "ding" from the dash with "please restart engine" or something like that. 

[KARNUT]

On 8/22/2025 at 1:11 PM, Atlas said:

 

Loaded question. You'll soon get all kinds of responses about how emissions have ruined modern diesels and it's all a problematic, unreliable nightmare AND its a government conspiracy designed to cost the consumer money. All while George Soros rides around in a jet and a farmer with a diesel tractor is put out of business because of DEF issues.

 

Most of the evidence is anecdotal and spiteful. My anecdotal evidence, having owned a few different modern diesels, is I've never had an issue. Whether by luck or just good maintenance, I've not had problems with SCR systems, EGR's or anything else. But I also don't modify my diesels or do things which cause issues like letting DEF go bad over seasons of no engine use, or using various fuel additives when the manufacturers say specifically don't do that. The reality few people talk about is the trucking industry and the billions of miles driven with SCR systems operational. For the most part people don't have problems, but it's certain you will hear about it when someone does. That provides a skew in both anecdotal evidence, and on forums, etc.

I don’t know how I missed this. In 1999 we sold our ROW clearing business. One of my brothers went along to run it for the new owner. The new owner really nails down cost. He loves spreadsheets. We only used diesel trucks. Fast forward to now. My brother and his son run 19 crews. The only diesel’s they run now are for pulling. Some crews use the smaller skid steer clearing machines. Emissions ruin the diesel trucks. Most needed to be deleted or serviced at around 100K miles. Diesel trucks went from being the most efficient most reliable trucks for work. To being more trouble than a gas work truck. I saw the 25 year transformation taking place. Most of his crews idle down pipelines during the day sometimes rarely being shut off. Then about a 20 minute ride to a motel for a ten day shift. Then a up to a 8 hour drive home. The emissions on diesel’s don’t like that. It’s a simple spreadsheet work project for the owner. It’s nothing other than cost analysis. Gas has taken over the least cost to run for longevity. There’s at least 5 backup trucks to rotate in service. They don’t start considering replacing until several hundred thousand miles. My other brother from the business I retired from runs gas service trucks. When I left 12 years ago it was diesel. No conspiracy, no agenda. 

[Atlas]

2 hours ago, KARNUT said:

I don’t know how I missed this. In 1999 we sold our ROW clearing business. One of my brothers went along to run it for the new owner. The new owner really nails down cost. He loves spreadsheets. We only used diesel trucks. Fast forward to now. My brother and his son run 19 crews. The only diesel’s they run now are for pulling. Some crews use the smaller skid steer clearing machines. Emissions ruin the diesel trucks. Most needed to be deleted or serviced at around 100K miles. Diesel trucks went from being the most efficient most reliable trucks for work. To being more trouble than a gas work truck. I saw the 25 year transformation taking place. Most of his crews idle down pipelines during the day sometimes rarely being shut off. Then about a 20 minute ride to a motel for a ten day shift. Then a up to a 8 hour drive home. The emissions on diesel’s don’t like that. It’s a simple spreadsheet work project for the owner. It’s nothing other than cost analysis. Gas has taken over the least cost to run for longevity. There’s at least 5 backup trucks to rotate in service. They don’t start considering replacing until several hundred thousand miles. My other brother from the business I retired from runs gas service trucks. When I left 12 years ago it was diesel. No conspiracy, no agenda. 

 

Yeah, how did you miss that? It's interesting, all the fleets that still run diesel where they need it. Maybe those fleet managers are just stupid and haven't ascended to the level of intelligence that your brother has. Clearly people still find a lot of value in diesel trucks.

 

But to that point, gas engines have really improved in power/efficiency with direct injection and turbos, now producing diesel-like torque down low and with cheaper fuel. The choice has become blurry in the light duty market. However, when you need 800, 1200 lb-ft of pulling power in a pickup, diesel is still the winning choice- even if there are a few more things to look after. The best solution isn't always the cheapest.

[KARNUT]

28 minutes ago, Atlas said:

 

Yeah, how did you miss that? It's interesting, all the fleets that still run diesel where they need it. Maybe those fleet managers are just stupid and haven't ascended to the level of intelligence that your brother has. Clearly people still find a lot of value in diesel trucks.

 

But to that point, gas engines have really improved in power/efficiency with direct injection and turbos, now producing diesel-like torque down low and with cheaper fuel. The choice has become blurry in the light duty market. However, when you need 800, 1200 lb-ft of pulling power in a pickup, diesel is still the winning choice- even if there are a few more things to look after. The best solution isn't always the cheapest.

Maybe you can see through your obvious hatred that I actually mentioned what they’re still good for. After actually witnessing the change over the years. I didn’t mention the hundreds of customers who pass through our business who actually have experience the same change over. If you can manage to read the words I actually wrote they still use them where needed. There’re not as cost effective as in the past. My words are from experience. Not I heard it somewhere from someone. Maybe you can learn something if you don’t have preconceived notions to have put KARNUT in his place. If the attempt to throw shade in your first paragraph was removed you’ll see we pretty much said the same thing. I didn’t mention the horsepower or TQ ratings because that’s a gimme since the beginning of the horsepower wars. What’s new is the loss of usefulness in the business world. I come from the business world and pass the experience from my eyes. No graphs, not a one off. Maybe if you put away your obvious distain you may get enlighten. You seem to only pick up words that may make your point. Even if the true meaning is right there in front of you. So I’ll wait for your next attempt to insult. But once again I’ll remind you that we pretty much said the same thing. 

Edited October 14, 2025 by KARNUT