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Chevrolet Silverado 2500HD
2020+

Factory gearing, tires, angles and brakes for the Silverado 2500HD, and what the usual upgrades do to it. Every number is from the maker's own figures unless the calculators say otherwise. A few figures here are still waiting on a factory document; the calculators mark them.

Use this truck in the calculators
158.9 in wheelbase · 40.2 in front · 50.7 in rear overhang
in
Stock tireLT245/75R1731.5 in tall
Axle ratio3.42–3.73Factory, by trim
Crawl ratio46.1:1Best trim: WT 4x4
Angles28.5 · 19 · 23.6°Approach, breakover, departure
Clearance10.1 inFactory figure
Highway mpg15Estimate, not EPA rated

Tire upgrades, worked out

WT 4x4, 3.42s, from LT245/75R17
TireHeightUnder the diffsSpeedo at 65RPM at 65Gears for dailyOpen
285/70R1732.7 in+0.6 in63 mph1,531Keep 3.42sOpen →
33x10.50R1733.0 in+0.8 in62 mph1,517Keep 3.42sOpen →
33x12.50R1733.0 in+0.8 in62 mph1,517Keep 3.42sOpen →
255/80R1733.1 in+0.8 in62 mph1,5144.1Open →
285/75R1733.8 in+1.2 in60 mph1,4804.1Open →
315/70R1734.4 in+1.4 in60 mph1,4574.1Open →
35x11.50R1735.0 in+1.8 in58 mph1,4304.1Open →
35x12.50R1735.0 in+1.8 in58 mph1,4304.1Open →
37x11.50R1737.0 in+2.8 in55 mph1,3534.1Open →
37x12.50R1737.0 in+2.8 in55 mph1,3534.1Open →

Stock turns 1,591 rpm at 65 in top gear. Flotation sizes are nominal; most measure a little short mounted.

Trims

5 we have figures for
TrimTireTransmissionAxleAnglesClearanceOpen
WT 4x4LT245/75R17Hydra-matic 6L90 6-speed automatic, Allison 10L1000 10-speed automatic3.42 / 3.7328.5* · 19* · 23.6*10.1 inUse →
Custom / LT 4x4 (17 in all-terrain)LT265/70R17Hydra-matic 6L90 6-speed automatic, Allison 10L1000 10-speed automatic3.42 / 3.7328.5* · 19* · 23.6*10.1 inUse →
LT 4x4 (18 in all-terrain)LT275/70R18Hydra-matic 6L90 6-speed automatic, Allison 10L1000 10-speed automatic3.42 / 3.7328.5* · 19* · 23.6*10.1 inUse →
18 in mud-terrain option (4x4)LT275/70R18Hydra-matic 6L90 6-speed automatic, Allison 10L1000 10-speed automatic3.42 / 3.7328.5* · 19* · 23.6*10.1 inUse →
LTZ / High Country (20 in)LT275/65R20Hydra-matic 6L90 6-speed automatic, Allison 10L1000 10-speed automatic3.42 / 3.7328.5 · 19 · 23.610.1 inUse →

* The maker doesn’t publish this figure for that trim, so it shows the closest trim’s (same tire where we have one), or a close relative’s that shares the same body or front end. Hover the star to see which.

Size

Wheelbase
158.9 in
Front overhang
40.2 in
Rear overhang
50.7 in
Height
76 in
Body
Pickup
Stock tires
LT245/75R17, LT265/70R17, LT275/65R20, LT275/70R18

Transmissions and low range

Hydra-matic 6L90 6-speed automatic (HD)
4.03 · 2.36 · 1.53 · 1.15 · 0.85 · 0.67
Allison 10L1000 10-speed automatic
4.54 · 2.87 · 2.06 · 1.72 · 1.48 · 1.26 · 1 · 0.85 · 0.69 · 0.63
Low range, autotrac-hd
2.72:1

Axles

Front
AAM 9.25 in IFS
Rear
AAM 11.5 in full-float (11.8 in on some Duramax)
3.42 ratio
WT 4x4, Custom / LT 4x4 (17 in all-terrain), LT 4x4 (18 in all-terrain), 18 in mud-terrain option (4x4), LTZ / High Country (20 in)
3.73 ratio
WT 4x4, Custom / LT 4x4 (17 in all-terrain), LT 4x4 (18 in all-terrain), 18 in mud-terrain option (4x4), LTZ / High Country (20 in)
Ratios made for it
4.1 · 4.56 · 4.88

Brakes

Front rotor
13.98 in, 355 mm
Front caliper piston
60.0 mm
Rear rotor
14.17 in, 360 mm
Rear
disc (vented, 360 x 34 mm)

Suspension

Front
double wishbone IFS, torsion bars (revised design for 2020)
Rear
multi-leaf springs, solid axle
Rear layout
Leaf springs

Fuel economy

Highway, not EPA rated
about 15 mpg
Where it comes from
Road test, 40% city / 60% highway mix (2020 Silverado 2500HD LTZ 6.6 Duramax, Allison 10-speed)

Aftermarket bumpers

15 listed

Makers almost never publish angles, bottom heights or how far a bumper tucks, so these fill in as owners measure them. Measured yours? Add it on the rig page and every owner of this Silverado 2500HD sees how it does on their tires and lift.

Front 9

Rear 6

Every calculator, set up for the Silverado 2500HD

Tire sizeBigger tires: speedo, clearance, angles and brakes.Compare tiresRegearHighway RPM on every ratio and mpg.Pick your gearsCrawl ratioHow slow it creeps, against other trucks.Work out crawlSpeedometerWhat it really reads on new tires.Fix your speedoLinksAnti-squat and what a lift does to it.Check your linksYour rigBuild sheet and measured angles.Start a build sheetLeaderboardsWhere the Silverado 2500HD ranks against every stock truck.See where it ranks

Source: auto-brochures.com. AAM 11.5 uses different carriers for 3.73-and-down vs 4.10-and-up.

Use at your own risk. These calculators are here to help you plan and to inform your decisions, not to sign off on a build. Many numbers are estimates worked out from factory figures, and some factory figures are not yet confirmed. Check every number against your own truck, its manuals and a qualified shop before you buy parts, cut, weld, lift, regear or drive on it. Long Range Desert Tools is not liable for anything you do based on these calculators or their results. The full terms are in our policies.