Find the biggest transmission fills before buying fluid
Dale Hutchins
· 1 min read
Compare estimated transmission fluid capacity for 150 Chevrolet truck configurations, with transmission, total-fill, and service-fill figures in quarts.
This table ranks 100 A Chevrolet truck model-year, powertrain, and drivetrain configurations by Total Fluid Capacity, highest first, with Total Fluid Capacity, Service Fill, Transmission for every entry and a one-line reason for each position. The figures are model-estimated, not measured; the method and its limits are below. At the top: 2020 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD at 20.6.
Click any column header to sort; type in the filter box to narrow the 100 rows.
Model-estimated ranking, methodology below. Every figure is an estimate produced for this table, not a measurement; treat the order as directional.
100 of 100 rows
| # | Configuration | Total Fluid Capacity (qt) | Service Fill (qt) | Transmission | Rationale |
|---|---|---|---|---|---|
| 1 | 2020 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | A large converter and factory cooler keep total capacity near 20.6 quarts. |
| 2 | 2020 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | The Duramax-coupled 10-speed has one of Chevrolet's largest light-truck fluid systems. |
| 3 | 2020 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | Its 10L1000 dry-fill volume is essentially unchanged by the two-wheel-drive layout. |
| 4 | 2020 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | The high-capacity 10L1000 and its heavy-duty cooling circuit place this configuration at the top. |
| 5 | 2021 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | The common 10L1000 pan, converter, and cooler arrangement supports this top-tier estimate. |
| 6 | 2021 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | Its ten-speed Allison-branded unit carries substantially more fluid than older six-speeds. |
| 7 | 2021 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | Deleting the transfer case does not materially reduce the automatic transmission's fluid volume. |
| 8 | 2021 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | This heavy-duty diesel retains the high-volume 10L1000 transmission and cooler circuit. |
| 9 | 2022 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | A full dry fill includes considerable fluid retained in the converter and cooling lines. |
| 10 | 2022 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | Its Duramax powertrain uses the high-capacity 10-speed rather than the smaller 6L90. |
| 11 | 2022 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | The two-wheel-drive model shares the same large transmission and cooling package. |
| 12 | 2022 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | Maximum-duty diesel hardware gives this truck a roughly 20.6-quart dry system. |
| 13 | 2023 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | The Duramax and 10L1000 pairing produces one of Chevrolet's highest total capacities. |
| 14 | 2023 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | Heavy towing requirements bring a large converter, pan, and external cooling circuit. |
| 15 | 2023 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | This diesel HD uses the same high-volume ten-speed despite its simpler driveline. |
| 16 | 2023 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | The 10L1000's large total volume remains consistent in this four-wheel-drive HD application. |
| 17 | 2024 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | This two-wheel-drive HD shares the diesel ten-speed's large dry-fill requirement. |
| 18 | 2024 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | The revised Duramax HD preserves the 10L1000's approximately 20.6-quart total fill. |
| 19 | 2024 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | Its transmission, converter, and cooling loop match the highest-capacity HD configurations. |
| 20 | 2024 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | Updated HD output still relies on the large-fluid-volume Allison-branded ten-speed. |
| 21 | 2024 Chevrolet Silverado 3500HD 6.6L gasoline V8 4WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | For 2024 the gasoline HD gained the same high-volume ten-speed architecture used with the Duramax. |
| 22 | 2025 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | The diesel 10-speed's full-system capacity greatly exceeds its routine pan service fill. |
| 23 | 2025 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | Its large torque converter and towing-oriented cooler account for the top-ranked capacity. |
| 24 | 2025 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | A common 10L1000 fluid system keeps this model level with the four-wheel-drive version. |
| 25 | 2025 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 20.6 | 7.4 | Allison-branded 10L1000 10-speed automatic | The maximum-duty Silverado continues with Chevrolet's high-capacity diesel ten-speed. |
| 26 | 2008 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 17.5 | 7.4 | Allison 1000 6-speed automatic | Its Allison transmission, converter, and factory cooling circuit give it a high dry-system capacity. |
| 27 | 2008 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 17.5 | 7.4 | Allison 1000 6-speed automatic | The heavy-duty Allison and diesel cooling circuit place this one-ton configuration near the top. |
| 28 | 2008 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 17.5 | 7.4 | Allison 1000 6-speed automatic | The Allison's large converter and external cooling circuit account for its substantial total fill. |
| 29 | 2015 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 17.5 | 7.4 | Allison 1000 6-speed automatic | This Duramax one-ton uses the high-capacity Allison with a sizable factory cooler circuit. |
| 30 | 2015 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 17.5 | 7.4 | Allison 1000 6-speed automatic | Its diesel-rated Allison system holds far more fluid dry than a routine pan service replaces. |
| 31 | 2007 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 17.3 | 7.4 | Allison 1000 6-speed automatic | The redesigned HD retained a large Allison converter and auxiliary cooler, supporting a high total. |
| 32 | 2007 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 17.3 | 7.4 | Allison 1000 6-speed automatic | Its six-speed Allison and diesel cooling hardware produce nearly the same capacity as later HDs. |
| 33 | 2007 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 17.3 | 7.4 | Allison 1000 6-speed automatic | The one-ton Duramax powertrain includes a large converter and cooler circuit with high fluid demand. |
| 34 | 2007 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 17.3 | 7.4 | Allison 1000 6-speed automatic | This four-wheel-drive one-ton shares the high-capacity Allison fluid circuit of its HD peers. |
| 35 | 2024 Chevrolet Silverado 2500HD 6.6L gasoline V8 2WD | 17.2 | 8.1 | Allison-branded 10L1000 10-speed automatic | Chevrolet's 2024 gas HD upgrade to the 10-speed sharply increased total fluid capacity over the former 6-speed. |
| 36 | 2024 Chevrolet Silverado 2500HD 6.6L gasoline V8 4WD | 17.2 | 8.1 | Allison-branded 10L1000 10-speed automatic | The large 10-speed assembly and factory transmission cooler account for its high estimated dry fill. |
| 37 | 2024 Chevrolet Silverado 3500HD 6.6L gasoline V8 2WD | 17.2 | 8.1 | Allison-branded 10L1000 10-speed automatic | Its 10-speed HD transmission holds more fluid than earlier gasoline 3500HD six-speed units. |
| 38 | 2025 Chevrolet Silverado 2500HD 6.6L gasoline V8 2WD | 17.2 | 8.1 | Allison-branded 10L1000 10-speed automatic | The large 10-speed, torque converter, and HD cooling circuit give the gas-powered Silverado substantial dry capacity. |
| 39 | 2025 Chevrolet Silverado 2500HD 6.6L gasoline V8 4WD | 17.2 | 8.1 | Allison-branded 10L1000 10-speed automatic | Its Allison-branded 10-speed and factory HD cooler place it among the highest-capacity gasoline truck configurations. |
| 40 | 2025 Chevrolet Silverado 3500HD 6.6L gasoline V8 2WD | 17.2 | 8.1 | Allison-branded 10L1000 10-speed automatic | The 3500HD gas model uses the high-capacity 10-speed with a sizable converter and cooling loop. |
| 41 | 2025 Chevrolet Silverado 3500HD 6.6L gasoline V8 4WD | 17.2 | 8.1 | Allison-branded 10L1000 10-speed automatic | This one-ton gas configuration carries the large Allison-branded 10-speed and an HD cooling circuit. |
| 42 | 2007 Chevrolet Silverado Classic 2500HD 6.6L Duramax diesel 2WD | 17.1 | 7.4 | Allison 1000 6-speed automatic | The Classic Duramax's six-speed Allison and external cooler keep its dry capacity comparatively high. |
| 43 | 2007 Chevrolet Silverado Classic 2500HD 6.6L Duramax diesel 4WD | 17.1 | 7.4 | Allison 1000 6-speed automatic | Its Allison converter and HD cooling loop hold considerably more than the normal service quantity. |
| 44 | 2007 Chevrolet Silverado Classic 3500 6.6L Duramax diesel 2WD | 17.1 | 7.4 | Allison 1000 6-speed automatic | This Classic one-ton combines the six-speed Allison with a substantial diesel towing cooler circuit. |
| 45 | 2007 Chevrolet Silverado Classic 3500 6.6L Duramax diesel 4WD | 17.1 | 7.4 | Allison 1000 6-speed automatic | The heavy-duty Allison system gives this Classic 4WD a large dry-fill requirement. |
| 46 | 2006 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 17 | 7.4 | Allison 1000 6-speed automatic | The first-year six-speed Allison application carries a large converter and towing cooler volume. |
| 47 | 2006 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 17 | 7.4 | Allison 1000 6-speed automatic | Its six-speed Allison fluid circuit is large, while a pan drain leaves much of it retained. |
| 48 | 2006 Chevrolet Silverado 3500 6.6L Duramax diesel 2WD | 17 | 7.4 | Allison 1000 6-speed automatic | The diesel one-ton's Allison, converter, and auxiliary cooler yield a high estimated total. |
| 49 | 2006 Chevrolet Silverado 3500 6.6L Duramax diesel 4WD | 17 | 7.4 | Allison 1000 6-speed automatic | Its towing-oriented Allison cooling circuit places it alongside other high-capacity Duramax trucks. |
| 50 | 2005 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 15.9 | 7.4 | Allison 1000 5-speed automatic | The earlier five-speed Allison has a slightly smaller dry system than the later six-speed version. |
| 51 | 2005 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 15.9 | 7.4 | Allison 1000 5-speed automatic | Its five-speed Allison and factory cooler still provide a large total despite the older design. |
| 52 | 2005 Chevrolet Silverado 3500 6.6L Duramax diesel 2WD | 15.9 | 7.4 | Allison 1000 5-speed automatic | The one-ton's diesel-rated five-speed and cooler circuit keep capacity above most light-duty units. |
| 53 | 2005 Chevrolet Silverado 3500 6.6L Duramax diesel 4WD | 15.9 | 7.4 | Allison 1000 5-speed automatic | This Duramax one-ton uses a large Allison system, though it trails newer six-speed installations. |
| 54 | 2004 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 15.7 | 7.4 | Allison 1000 5-speed automatic | Its early Allison five-speed has substantial converter and cooler volume but less than later units. |
| 55 | 2004 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 15.7 | 7.4 | Allison 1000 5-speed automatic | The HD cooling loop raises total capacity well beyond the amount recovered in routine service. |
| 56 | 2004 Chevrolet Silverado 3500 6.6L Duramax diesel 2WD | 15.7 | 7.4 | Allison 1000 5-speed automatic | The five-speed Allison and one-ton towing cooler create a sizable but generation-limited total. |
| 57 | 2004 Chevrolet Silverado 3500 6.6L Duramax diesel 4WD | 15.7 | 7.4 | Allison 1000 5-speed automatic | Its early Duramax Allison system remains high-capacity, with much fluid retained during a pan drain. |
| 58 | 2008 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | Its six-speed Allison, torque converter, and stock cooler together hold an estimated 12.7 quarts. |
| 59 | 2009 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The Duramax's six-speed Allison system carries about 12.7 quarts across the case, converter, and cooler. |
| 60 | 2009 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | A routine drain replaces roughly 7.4 quarts because substantial fluid remains outside the pan. |
| 61 | 2009 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The 3500HD uses the same Allison 1000 fluid system as comparable Duramax 2500HD configurations. |
| 62 | 2009 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | Four-wheel-drive hardware is lubricated separately, so Allison capacity remains approximately 12.7 quarts. |
| 63 | 2010 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | This six-speed Allison installation has an overhaul capacity near 12.7 quarts and a smaller routine refill. |
| 64 | 2010 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | Factory cooling and torque-converter retention keep a pan-drain refill well below total capacity. |
| 65 | 2010 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The Allison 1000's heavy-duty case and cooling loop support an estimated 12.7-quart dry fill. |
| 66 | 2010 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | Its separate transfer case does not add to the automatic transmission's measured fluid capacity. |
| 67 | 2011 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The redesigned HD retained an Allison 1000 system holding about 12.7 quarts when dry. |
| 68 | 2011 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | Its drivetrain adds a transfer case but leaves estimated automatic-transmission capacity near 12.7 quarts. |
| 69 | 2011 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | A standard drain leaves fluid in the converter and cooling lines, limiting service fill to about 7.4 quarts. |
| 70 | 2011 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The Duramax-rated Allison and external cooler produce the same estimated volume as the 2WD version. |
| 71 | 2012 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | This model uses the same large Allison case, converter, and cooler arrangement as adjacent Duramax HD years. |
| 72 | 2012 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The retained converter and cooler fluid explain the gap between service fill and total capacity. |
| 73 | 2012 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | Its factory Allison 1000 installation yields an estimated complete-system capacity of 12.7 quarts. |
| 74 | 2012 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | Heavy-duty cooling and converter volume place this truck among the larger six-speed fluid systems. |
| 75 | 2013 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The six-speed Allison and torque converter account for a substantially larger total than a pan drain. |
| 76 | 2013 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | A typical pan service replaces about 7.4 quarts while the complete system holds roughly 12.7. |
| 77 | 2013 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | Duramax pairing, converter volume, and auxiliary cooling keep this configuration near 12.7 quarts total. |
| 78 | 2013 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The Allison system capacity is unchanged by 4WD because transfer-case lubricant is separate. |
| 79 | 2014 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The Allison 1000's converter and factory cooling circuit put dry capacity near 12.7 quarts. |
| 80 | 2014 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | Four-wheel drive does not materially change the Allison transmission's fluid volume. |
| 81 | 2014 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | This heavy-duty Duramax configuration uses the high-capacity Allison 1000 and external cooling circuit. |
| 82 | 2014 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | Its Allison 1000 dry fill remains about 12.7 quarts despite the separate transfer case. |
| 83 | 2015 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | Its LML Duramax is coupled to the standard-sump Allison 1000 with a roughly 7.4-quart service fill. |
| 84 | 2015 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The converter and cooling circuit lift full dry capacity well above the amount replaced in a pan service. |
| 85 | 2016 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The LML Duramax and Allison 1000 combination carries an estimated 12.7-quart complete-system fill. |
| 86 | 2016 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | A routine pan drain leaves fluid in the Allison converter and cooler, limiting service fill to about 7.4 quarts. |
| 87 | 2016 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | Its one-ton rating does not alter the basic Allison 1000 sump, converter, or stock cooler capacity. |
| 88 | 2016 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The proven six-speed Allison system holds roughly 12.7 quarts when fully dry. |
| 89 | 2017 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The first-year L5P powertrain retained the established Allison 1000 fluid-volume range. |
| 90 | 2017 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | Its stock sump drains about 7.4 quarts, while the converter and cooler raise total capacity to about 12.7. |
| 91 | 2017 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | This 3500HD uses the same Allison six-speed fluid system fitted to other L5P Duramax models. |
| 92 | 2017 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The heavy-duty Allison hardware provides substantial capacity, though less than the later 10-speed. |
| 93 | 2018 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The L5P Duramax's Allison six-speed retains about 12.7 quarts across the transmission and cooling circuit. |
| 94 | 2018 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | A standard pan service replaces far less than the full volume retained by the converter and cooler. |
| 95 | 2018 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | Its Allison 1000 shares the same estimated dry and service-fill volumes as other 2018 Duramax HD trucks. |
| 96 | 2018 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The factory Allison six-speed and cooling hardware yield a capacity near 12.7 quarts. |
| 97 | 2019 Chevrolet Silverado 2500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The Duramax-paired Allison 1000 has a moderate 12.7-quart dry-system estimate and a smaller routine drain fill. |
| 98 | 2019 Chevrolet Silverado 2500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | Its six-speed Allison, converter, and stock cooler combine for roughly 12.7 quarts when fully dry. |
| 99 | 2019 Chevrolet Silverado 3500HD 6.6L Duramax diesel 2WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | The one-ton Duramax uses the same high-duty Allison 1000 fluid system as the contemporary 2500HD. |
| 100 | 2019 Chevrolet Silverado 3500HD 6.6L Duramax diesel 4WD | 12.7 | 7.4 | Allison 1000 6-speed automatic | Four-wheel drive does not materially change the separate Allison 1000 transmission fluid volume. |
Methodology. Total capacity estimates represent a dry transmission, torque converter, and typical factory cooling circuit. Figures are based on Chevrolet service information, owner manuals, and transmission specifications; service-fill amounts vary with draining method, cooler size, and retained fluid. Rows are ranked by Total Fluid Capacity (highest first); the rationale column states why each entry sits where it does.
How This Ranking Was Built
Total capacity estimates represent a dry transmission, torque converter, and typical factory cooling circuit. Figures are based on Chevrolet service information, owner manuals, and transmission specifications; service-fill amounts vary with draining method, cooler size, and retained fluid. This is a model-estimated ranking: the values were produced by a language model asked for consistent estimates across rows, then sorted and rank-checked by code. Treat the order as directional and check any single figure against a primary source before relying on it.