Used Chevy Silverado HD (2020-2024): Buyer's Guide

Some used Duramax Silverado HD trucks don't have their DPF anymore. The previous owners removed it, deleted the emissions tune, and sold the truck without disclosing any of it. Restoring a deleted diesel to emissions compliance costs $5,000 to $10,000 in parts and labor. There's no warning light. There's no dashboard message. If you don't know what to look for under the truck, you will not know. And if you live in a state with emissions testing, that truck will fail inspection until you pay to fix it.

That's not the only thing a used Silverado 2500HD or 3500HD buyer needs to know about the 2020-current generation. The 2020-2022 diesel also has an active safety recall for a transmission control valve failure that can lock the rear wheels at highway speed. The gas engine has documented oil consumption complaints GM calls "acceptable." And the entire generation split into a meaningfully different truck at the 2024 model year.

This guide covers the fourth-generation Silverado HD: 2500HD and 3500HD, 2020 through 2024.

This Generation at a Glance

Chevrolet redesigned the Silverado HD for 2020 on the new T1 platform. The truck grew in size and got a fully-boxed frame GM claims is 20% stiffer than the third generation. Tow ratings jumped from 14,500 pounds to 20,000 pounds on a conventional hitch for the 2500HD.

Two distinct periods exist within this generation:

2020-2023: The original T1 launch configuration. Gas V8 with a 6-speed automatic. Diesel with the Allison 10-speed. Older-style infotainment on most trims.

2024+: A mid-cycle refresh. New 13.4-inch touchscreen. 12.3-inch digital cluster. Redesigned front end with C-shaped LED headlights. The gas engine now uses a 10-speed automatic instead of the 6-speed. The diesel gained 25 horsepower and 65 lb-ft of torque.

The 2024 refresh is significant enough that you're comparing two different ownership propositions when cross-shopping a 2023 against a 2024.

Heavy-duty trucks over 8,500 lb GVWR are exempt from EPA fuel economy labeling. Owner-reported figures are in the Running Costs section.

See Silverado market data by year: 2020 | 2021 | 2022 | 2023 | 2024

Powertrain and Trim Breakdown

6.6L L8T V8 Gas: Simpler, But Not Issue-Free

The L8T is a 6.6-liter V8 making 401 horsepower and 464 lb-ft of torque. It does not have Active Fuel Management (AFM) or Dynamic Fuel Management (DFM). This matters: the cylinder-deactivation lifter failures that plague the 5.3L in the Silverado 1500 are not a risk with the L8T. The HD gas engine is a simpler, more conventional V8 without that failure mode.

That does not make it trouble-free.

Oil consumption is the primary documented concern. GM-Trucks.com forums contain ongoing threads from owners reporting the L8T burning oil at a rate that depletes the dipstick between 3,000-mile oil changes. GM's own guidelines state that consuming one quart per 100 gallons of fuel (roughly one quart per 2,000-3,000 miles for most drivers) is "acceptable" and within spec. Many owners disagree. If you're buying a used L8T, ask about consumption history. Pull recent oil change receipts and compare dates to mileage. A truck that routinely needs a top-up between changes has either a known consumption issue or a seal problem.

Crankshaft balancer on 2022 gas models was the subject of a GM service update after some units shipped with improperly seated balancers. The issue causes harsh vibration and accelerated drivetrain wear. GM addressed it under a warranty service bulletin. On any 2022 L8T you're considering, ask the dealer to confirm the service update was completed.

Engine tick: GM officially states that a typewriter-style ticking sound from the L8T is normal engine behavior. The noise typically appears cold and may persist for up to ten minutes. Per GM Authority reporting in April 2026, GM told dealers to consider this sound normal operation. If you hear this noise on a test drive, it is documented and common. Whether to walk away is a personal call, but it is not a red flag unique to one truck.

Dual-tank fuel starvation affects a specific subset of 2020-2022 L8T chassis-cab models equipped with the two-tank option (RPO code N2N). The fuel transfer system can fail, leaving fuel stranded in the rear tank while the front tank reads empty. GM investigated this in 2026. Not applicable to standard crew cab or regular cab models with a single tank.

Transmission: The 6-speed automatic paired with the L8T on 2020-2023 models is a simpler unit than the Allison behind the diesel. Service Bulletin 22-NA-182 addressed harsh shifting, shudder, and surging on 2021-2023 L8T trucks. Check for this TSB completion on any 2021-2023 gas model that exhibits rough shifting.

For 2024+, the new 10-speed automatic addresses many of the durability questions about the 6-speed. The first year of any new transmission calibration tends to surface issues; monitor for service bulletins on 2024 L8T trucks before assuming the 10-speed is refined.

Bottom line on the L8T: Better for daily driving, shop work, occasional towing under 10,000 pounds, and buyers who prefer simpler emissions-free ownership. Cheaper to buy. Every shop knows how to service it. No DEF, no DPF, no emissions system to worry about.

6.6L L5P Duramax Diesel: High Reward, High Homework

The L5P Duramax makes 445 hp and 910 lb-ft of torque in 2020-2023 configuration. In 2024+, those numbers climb to 470 hp and 975 lb-ft. That torque figure doubles the L8T's output. If you tow heavy loads regularly, the diesel is the correct choice. At 10,000-15,000 pounds, the difference is immediately noticeable. Owners on DuraMaxForum.com consistently report: "once you've towed heavy with a diesel, you won't go back."

Owner-reported fuel economy supports the premium: 15-18 mpg unloaded, 10-12 mpg towing 12,000-15,000 pounds. The L8T gets 8-10 mpg under the same towing load.

The transmission recall you must verify. GM issued Recall N242454440 (NHTSA campaign 24V797) covering 2020-2022 Silverado HD and Sierra HD trucks with Duramax diesel engines. A worn transmission control valve body can cause fluid pressure to drop, shift valves to move unexpectedly, and in rare cases lock the rear wheels during a downshift from eighth gear. The truck may also display a "Reduced Propulsion" message. The fix is a free software update that adds valve body wear monitoring. Approximately 462,000 vehicles were affected. On any 2020, 2021, or 2022 diesel you are buying, confirm this recall was completed at a dealer before purchase. Pull the VIN at /tools/recall-lookup first.

DEF and emissions system. The L5P relies on a Diesel Exhaust Fluid (DEF) system and Diesel Particulate Filter (DPF) to meet emissions standards. This system has multiple failure points:

• NOX sensors: False failure reports are common. GM issued a TSB in April 2021 specifically addressing false NOX sensor failure codes on Silverado HD and Sierra HD Duramax models. NOX sensor replacement runs $600-$700 including labor. Some owners have replaced multiple sensors over the truck's life.
• DEF pump: Failure causes the truck to enter a progressive derate, eventually limiting speed to 5 mph, then a no-start condition. Replacement cost: $1,800-$2,200 at dealers.
• DEF injector and DPF: Full aftertreatment system replacement in severe cases runs $3,000-$4,000. Forum threads on DieselPlace.com and DuraMaxForum.com cover multi-page owner accounts of this failure chain.
• EGR cooler: The EGR assembly requires cleaning at around 75,000 miles. A cracked cooler mixes exhaust gases into the coolant loop. Cost to clean and inspect: $500-$1,500.

Emissions deletion. This is the most important pre-purchase concern for used diesels. Many owners remove the DPF and install an aftermarket tune to eliminate the emissions system. The truck runs fine and throws no warning lights with the delete. To detect a deleted truck:

1. Crawl under the truck between the transmission and rear axle. A stock Duramax has a large cylindrical DPF canister. A deleted truck has straight pipe or aftermarket exhaust where that canister should be.
2. Look for an OBD-II programmer or tuner plugged into the port under the dashboard.
3. Check the DEF gauge on the instrument cluster. On a deleted truck, the DEF level never drops.
4. Ask an OBD-II scanner to pull emissions-related codes and freeze frame data.

Walk away from any deleted diesel unless you are prepared to pay $5,000-$10,000 to restore it to stock.

Allison 10-speed: The transmission behind the L5P is the Allison 10-speed, separate from the GM-designed 10-speed used in the gas truck. The Allison has a strong long-term reliability reputation. The recall software update on 2020-2022 trucks addresses the valve body wear issue. Post-recall, forum consensus on DuraMaxForum.com is that the Allison holds up well under towing loads when properly maintained.

Model-year-specific notes for diesel:

• 2020-2022: Transmission recall required. First-year 2020 models had more cumulative recall exposure than later years. Verify all outstanding campaigns before purchase.
• 2021: COVID-era supply chain disruptions resulted in some trucks missing options that were listed on the window sticker. Physically confirm features are present.
• 2023: Best reliability profile for the pre-refresh diesel. Fewer open recalls.
• 2024: New diesel output (470 hp / 975 lb-ft). Steering gear shaft fracture recall (NHTSA campaign covering certain 2024 models). Verify completion on any 2024 you are buying.

Trim-Specific Notes

The Silverado HD runs five trims: WT, Custom, LT, LTZ, and High Country.

WT (Work Truck): Bare bones. Gets the diesel option. No heated seats, no large infotainment screen, vinyl flooring. Correct for commercial or fleet buyers who want maximum capability with minimal interior technology to fail.

Custom: The only trim that cannot be ordered with the Duramax diesel. If you need diesel, avoid the Custom trim. Its existence as a trim-level diesel exclusion catches buyers off guard. If you find a used Custom and want to know why there's no diesel option, now you know.

LT: The used-market sweet spot. Gets diesel availability, heated front seats, and the infotainment system without the High Country price premium. Most used Silverado HD inventory sits in LT and LTZ trim.

LTZ: Step up from LT adds leather, more driver assistance features, and Z71 off-road package availability (on LTZ only for the pre-2024 models). The Z71 suspension package adds skid plates and different shock valving. If you're buying a Silverado HD for work that includes rough terrain, LTZ with Z71 is the practical choice over High Country.

High Country: The luxury-focused trim. 20-inch wheels, premium Stitched leather, ventilated and heated front seats, power running boards. The power boards are an additional suspension and mechanism component to inspect. High Country on the used market carries a meaningful premium over LTZ for features most towing-focused buyers don't need. Worth it if you spend significant time in the cabin. Not worth it if the truck mostly works.

Multi-Flex Tailgate: Available from 2022 forward on upper trims. The tailgate opens in six configurations. Forum threads show minor concerns about the mechanism's complexity versus the simpler standard tailgate. Not a reliability issue at this generation's mileage range, but a consideration on higher-mileage examples.

Which Model Years to Target

The 2023 is the sweet spot for buyers who want the pre-refresh generation without paying 2024 prices. It carries lower recall exposure than 2020-2022, all the content improvements accumulated over four model years, and the longest established reliability track record within this generation.

The 2024 is worth the premium if the new interior and 10-speed transmission matter to you. The 2024 diesel with 470 hp and 975 lb-ft is meaningfully more capable than the 2023's 445 hp and 910 lb-ft.

Avoid the 2020 as a first choice. It's not a bad truck, but it carries more first-year issues and more open recall exposure than any subsequent year in this generation.

Pre-Purchase Inspection Checklist

For Any Silverado HD (Gas or Diesel)

• Verify the power tailgate recall (affecting 2020-2024 power-unlatching units) is complete using the VIN at /tools/recall-lookup.
• Check the battery health. HD trucks use a dual-battery setup. Both batteries should test above 12.4 volts at rest. Dead or weak secondary batteries indicate deferred maintenance.
• Inspect the frame rails and crossmembers for rust, especially in northern-state trucks. The T1 platform's boxed frame is more resistant to rust than older open-rail designs, but undercarriage corrosion accelerates when maintenance is deferred.
• Pull codes with an OBD-II scanner before the test drive, not after. You want freeze frame data from before a seller-cleared reset.

Gas (L8T) Specific

• Pull the dipstick after warming the engine. Ask when the last oil change was and how many miles ago. A significantly low dipstick on a recently changed engine indicates active consumption.
• On 2022 models, ask about crankshaft balancer service bulletin completion.
• Start cold. The engine tick is common and GM considers it normal. Document it and note whether it persists beyond ten minutes at operating temperature. Sustained tick at operating temperature warrants investigation.
• For 2020-2023 models, request transmission service records. Service Bulletin 22-NA-182 addresses shifting concerns. A truck with no service history on the transmission and a complaint history of rough shifts is a yellow flag.

Diesel (L5P) Specific

• Crawl under before the test drive. Locate the DPF canister between the transmission and rear axle. If it's missing or replaced with straight pipe, walk away.
• Check the OBD-II port for a tuner or programmer left plugged in.
• Watch the DEF gauge on startup. It should show a real level. Freeze it at full or showing unrealistic range is a deletion indicator.
• On 2020, 2021, or 2022 models: confirm the transmission recall N242454440 was completed at a dealership. Ask for the dealer work order. "It was done" without documentation is not confirmation.
• Listen at idle for injector rattle or rough combustion. A diesel that's had maintenance deferred on fuel filters develops rough idle at cold start.
• Ask about DEF pump and NOX sensor service history. If the truck has over 80,000 miles and never had a DEF pump or sensor touched, factor $1,800-$2,200 into your negotiation as a near-term cost.
• On 2024 models, verify the steering gear shaft fracture recall was completed.

Running Costs

Heavy-duty trucks over 8,500 lb GVWR are not rated by the EPA. The figures below are owner-reported.

Diesel-specific ongoing costs:

• DEF fluid: $10-15 per 2.5-gallon jug, roughly every 5,000-8,000 miles depending on load
• Diesel fuel filters: Replace every 15,000 miles. Cost $80-$120 at a shop.
• EGR cooler service: ~$500-$1,500 at 75,000 miles
• NOX sensor (if failed): $600-$700

The diesel premium at purchase is typically $7,000-$10,000 over the equivalent gas truck. The fuel economy advantage on highway driving unloaded partially closes that gap over time. If you tow daily at high weights, the diesel pays back faster. If you tow occasionally, the math rarely closes.

FAQ

Is the 2020 Silverado 2500HD reliable? The 2020 is a legitimate truck but it's the first-year launch for the T1 platform. It carries the most NHTSA recall exposure of any year in this generation, including the diesel transmission recall affecting 2020-2022 models. Verify all recalls are closed before buying. The 2021 or later is a cleaner purchase if the budget allows.

Which is better: the gas or diesel Silverado 2500HD? For occasional towing under 12,000 pounds and daily driving, the L8T gas is simpler and cheaper to own. No DEF, no DPF, no emissions system complexity. For regular towing at 12,000-20,000 pounds, the L5P Duramax is decisively better. Nearly double the torque makes a real difference under load, and fuel economy while towing is meaningfully better.

How do I tell if a used Duramax was deleted? Crawl under the truck between the transmission and rear axle and look for the DPF canister. A stock truck has a large cylindrical canister. A deleted truck has a straight pipe where that canister was. Also check the DEF gauge for signs it never drops, and look for an OBD-II tuner plugged under the dash.

Does the Duramax in the 2500HD have the same problems as the 5.3L in the Silverado 1500? No. The 5.3L AFM/DFM lifter failures come from cylinder deactivation technology the L8T and L5P do not have. These are fundamentally different powertrains. The HD engines have their own documented issues, but cylinder deactivation lifter failure is not among them.

What year Silverado 2500HD is the best to buy used? In the T1 generation, the 2023 is the best value before the refresh. It has the lowest recall exposure of the pre-2024 trucks, the full set of features accumulated over four model years, and an established track record. The 2024 is the best overall if you want the new interior and 10-speed gas transmission.

Bottom Line

Run every VIN through a recall check before anything else, especially on any 2020-2022 diesel. The sweet spot in this generation is the 2023 gas or diesel, depending on your towing needs. The 2023 LT with the Duramax diesel gives you the maximum towing capability at the lowest recall risk in the pre-refresh lineup. For lighter use and simpler ownership, the 2023 LT with the L8T costs less to buy and less to maintain.

CarScout members can set alerts on specific Silverado HD years and trims at usecarscout.com and track price drops without refreshing listings manually.

Data sourced from NHTSA recalls database, GM technical service bulletins, EPA fuel economy exemption documentation, and real owner experiences from GM-Trucks.com, DuraMaxForum.com, SilveradoSierra.com, DieselPlace.com, and TractorByNet.com forums. See the full Chevrolet Silverado market data for current pricing and inventory.