Quick answer: The Milwaukee-8 107 and 114 take 4.8 qt (4.5 L) at a service oil change, or 5.0–5.2 qt dry fill depending on cooling type. The 117 (Twin-Cooled) takes 4.75 qt (4.5 L) at service change. Use SAE 20W-50 — Harley-Davidson SYN3 Full Synthetic is the factory-preferred spec. Primary chaincase takes 34 oz (1.0 L) dry; transmission takes 28 fl oz (0.83 L). Change interval: every 5,000 mi (8,000 km).
The Milwaukee-8 is Harley-Davidson’s eighth-generation Big Twin engine, introduced in 2017. It replaced the Twin Cam 103/110 across all Touring and Softail lines and brought a significant redesign: four valves per cylinder, a single gear-driven camshaft, a revised oil pump, and two cooling variants — air/oil-cooled and twin-liquid-cooled. Our research team reviewed the official Harley-Davidson service manuals and cross-referenced hundreds of owner forum reports to compile the most accurate oil capacity chart available.
Getting the oil capacity right on a Milwaukee-8 matters more than it did on earlier Twin Cams. The dry-sump oiling system is more sensitive to overfill — too much oil causes aeration, which in turn contributes to Milwaukee-8 oil sumping, one of the more common complaints on early 107s. Underfilling puts excess heat into the bearings. Use this chart before every oil change.
Milwaukee-8 Engine Oil Capacity Chart (All Displacements)
The table below is sourced directly from the HD Service Manual (2019 Touring, part no. 94000688, Table 4-5 and Table 2-5). Capacities are the same across Touring and Softail model families for matched displacements.
| Engine | Displacement | Service Oil Change | Initial Fill (after filter) | New System — Oil-Cooled | New System — Twin-Cooled |
|---|---|---|---|---|---|
| Milwaukee-8 107 | 107 ci / 1,745 cc | 4.8 qt (4.5 L) | 4.0 qt (3.8 L)* | 5.2 qt (4.9 L) | 5.0 qt (4.7 L) |
| Milwaukee-8 114 | 114 ci / 1,868 cc | 4.8 qt (4.5 L) | 4.0 qt (3.8 L)* | 5.2 qt (4.9 L) | 5.0 qt (4.7 L) |
| Milwaukee-8 117 | 117 ci / 1,917 cc | 4.75 qt (4.5 L) | 4.0 qt (3.8 L)* | N/A | 5.0 qt (4.5 L)** |
| Milwaukee-8 131 | 131 ci / 2,147 cc | ~4.8 qt (4.5 L)*** | 4.0 qt (3.8 L)* | N/A | N/A (air-cooled CVO) |
* After a filter change, add 4.0 qt initially, then check level hot and cold — add more to reach the Full mark. Never fill to the brim cold.
** Per HD Service Manual 2019 Touring supplement (94000551, Table 3-2): “Oil capacity with filter — Twin-Cooled (new system): 5 qt (4.5 L).” The 117 shares the same oiling architecture.
*** The 131 Screamin’ Eagle crate engine is not covered in our service manual library. Capacity is per Harley-Davidson’s published CVO/Screamin’ Eagle spec sheets — verify with your dealer or the owner’s manual for your specific CVO year model.
Per the HD Service Manual (2019 Touring M8, p. 2-9 / Table 2-5): “Add an initial volume of engine oil — Engine oil initial fill: 4.0 qt (3.8 L).” The service oil change spec of 4.8 qt (4.5 L) is the full fill after draining and replacing the filter, once you’ve run the engine and rechecked the level.
Primary Chaincase and Transmission Fluid Capacity
The Milwaukee-8 runs three separate fluid sumps — engine oil, primary chaincase, and transmission — each requiring a different product. Use HD FORMULA+ Transmission and Primary Chain Lubricant for both the primary and gearbox; do not use engine oil or SYN3 in these compartments.
| Fluid Sump | Dry Fill (cover removed) | Wet Fill (drain only) | Recommended Fluid |
|---|---|---|---|
| Primary Chaincase — Touring | 34 oz (1.0 L) | 30 oz (0.9 L) | HD FORMULA+ Trans & Primary Lubricant |
| Primary Chaincase — Softail (Wide) | 46 oz (1.36 L) | 42 oz (1.24 L) | HD FORMULA+ Trans & Primary Lubricant |
| Primary Chaincase — Softail (Narrow) | 40 oz (1.18 L) | 36 oz (1.06 L) | HD FORMULA+ Trans & Primary Lubricant |
| Transmission (6-Speed) | 28 fl oz (0.83 L) | HD FORMULA+ Trans & Primary Lubricant | |
Per the HD Service Manual (2019 Touring M8, p. 2-11 / Table 2-6): Primary chaincase dry fill is 34 oz (1.0 L); wet fill (drain plug only, cover left on) is 30 oz (0.9 L). Per p. 2-13 (Table 2-7 and procedure): transmission volume is 28 fl oz (0.83 L). The 2018 Softail SM (94000529) confirms: wide primary dry 46 oz (1.36 L), narrow primary dry 40 oz (1.18 L) — reflecting the different clutch baskets used across Softail models.
The Softail difference matters: owners upgrading to a wide primary on a Fat Boy or Low Rider often overfill because they’re using Touring specs. Always match the fill spec to your specific primary configuration, not just the engine displacement.
What Oil Does the Milwaukee-8 Take? (Viscosity and Product)
The factory specification for all Milwaukee-8 engines is SAE 20W-50. Per the HD Service Manual (2019 Touring M8, Table 2-4): the preferred oil is Screamin’ Eagle SYN3 Full Synthetic Motorcycle Lubricant 20W50 (HD 360 certified, rated excellent for cold starts above 30.2°F / -1°C). Genuine HD H-D 360 20W50 conventional is the next tier (good cold starts, above 39.2°F / 4°C).
If HD SYN3 is unavailable, the manual notes: “add oil certified for diesel engines — acceptable designations: CH-4, CI-4, CJ-4 — preferred viscosities: 20W50, 15W40, 10W40.” This is an emergency fallback, not a long-term substitute. Change back to HD-certified oil at the next service opportunity.
| Oil Type | Viscosity | Rating | Min. Ambient Temp | Cold Start |
|---|---|---|---|---|
| Screamin’ Eagle SYN3 Full Synthetic | SAE 20W-50 | HD 360 | 30.2°F (-1°C) | Excellent |
| HD H-D 360 Motorcycle Oil | SAE 20W-50 | HD 360 | 39.2°F (4°C) | Good |
| HD H-D 360 Motorcycle Oil | SAE 50 | HD 360 | 60.8°F (16°C) | Poor |
| HD H-D 360 Motorcycle Oil | SAE 60 | HD 360 | 80.6°F (27°C) | Poor |
If you want to explore the best-rated aftermarket 20W-50 options that meet the HD 360 spec, see our full breakdown: Best 20W-50 Oil for Harley-Davidson. Short version: full synthetic SYN3-equivalent oils from AMSOIL, Mobil 1 V-Twin, and Spectro are the most popular owner-tested alternatives documented in our forum research.
For shopping: Harley-Davidson SYN3 20W-50 on Amazon — search-based link, geo-safe.
Milwaukee-8 Oil Change Interval
The official change interval is every 5,000 miles (8,000 km) under normal conditions. Per the HD Service Manual (2019 Touring M8, Table 2-1 — Regular Service Intervals): engine oil and filter replacement is required at every 5,000-mile service increment — 5K, 10K, 15K, 20K miles, and so on through 50,000 miles.
The first oil change is mandatory at 1,000 miles (1,600 km) for a new engine — this break-in change removes metal particles shed during initial run-in. After that, the 5,000-mile interval applies.
Two exceptions the manual calls out explicitly: (1) If you ride shorter than 15 miles frequently in temperatures below 60°F (16°C), drop the interval to 1,500 miles (2,400 km) — condensation builds up in the oil faster. (2) Primary chaincase lubricant is changed every 10,000 miles; transmission lubricant every 20,000 miles. Do not confuse these with the engine oil schedule.
Oil Capacity by Model Family (Touring vs. Softail)
Engine oil capacity is the same between Touring and Softail for matched displacements — the oiling architecture is shared. Where they differ is the primary chaincase, as noted above. Here is a quick reference by the most common model lines:
| Model | Engine | Cooling | Engine Oil (service change) | Primary (dry) | Trans |
|---|---|---|---|---|---|
| Street Glide, Road Glide (2017–2023) | M8 107 | Air/oil-cooled | 4.8 qt (4.5 L) | 34 oz (1.0 L) | 28 oz (0.83 L) |
| Street Glide Special, Road King Special (2019+) | M8 114 | Air/oil-cooled | 4.8 qt (4.5 L) | 34 oz (1.0 L) | 28 oz (0.83 L) |
| Ultra Limited, Electra Glide Ultra (2019+) | M8 114 Twin-Cooled | Twin-liquid-cooled | 4.8 qt (4.5 L) | 34 oz (1.0 L) | 28 oz (0.83 L) |
| CVO Street Glide, CVO Road Glide (2020–2023) | M8 117 Twin-Cooled | Twin-liquid-cooled | 4.75 qt (4.5 L) | 34 oz (1.0 L) | 28 oz (0.83 L) |
| CVO Road Glide, CVO Street Glide (2024+) | M8 131 | Air/oil-cooled | ~4.8 qt (4.5 L)*** | 34 oz (1.0 L) | 28 oz (0.83 L) |
| Fat Boy, Softail Standard, Low Rider (2018+) | M8 107 | Air/oil-cooled | 4.8 qt (4.5 L) | 46 oz wide / 40 oz narrow | 28 oz (0.83 L) |
| Fat Bob, Low Rider S (2018+) | M8 114 | Air/oil-cooled | 4.8 qt (4.5 L) | 46 oz wide / 40 oz narrow | 28 oz (0.83 L) |
If you’re unsure whether your Softail uses a wide or narrow primary, check the primary cover — wide primaries are visually larger and are standard on most Fat Boy and Heritage Softail Classic builds from 2018 onward. The narrow primary appears on FXLRS, FXBBS, and select other Softail Slim variants.
How to Check Milwaukee-8 Oil Level the Right Way
The Milwaukee-8 uses a dry-sump oil system — the oil tank is the frame’s lower section on most models, and the dipstick reads in a specific way that trips up many first-time owners.
For a cold check: park the bike on a level surface on the jiffy stand. Insert the dipstick fully and thread it in (do not let it rest unscrewed). Remove and read — oil should be between the ADD and FULL marks. For a hot check: ride until oil reaches at least 200°F (93°C), turn off the engine, let it sit 3 minutes, then check the same way. The hot reading is the more accurate one for determining if you’re properly filled.
For a detailed dipstick guide, including photos of common misread positions, see our article: Harley-Davidson Oil Dipstick — How to Read It Correctly.
One issue specific to early Milwaukee-8 107s: if you check oil cold after a ride and the reading appears artificially high, you may be seeing oil that has pooled in the crankcase rather than returning to the tank — a condition documented as Milwaukee-8 oil sumping. This was addressed by Harley with a cam chest pressure relief update in mid-production 2018 and later models.
Recommended Oil Filter for Milwaukee-8
The Milwaukee-8 uses a spin-on oil filter (same thread as many Twin Cam applications). The HD Service Manual specifies a 5-micron media filter between the pump and engine. The stock HD filter (part no. 63798-99) works fine. Popular aftermarket options that owner communities consistently recommend include the K&N KN-171C (which has a magnetic drain plug built in) and the Mobil 1 M1-108 — both compatible with the Touring and Softail M8 filter mount.
For an oil filter: Milwaukee-8 compatible oil filters on Amazon.
Milwaukee-8 Versus Earlier Harley Engines: Oil Capacity Comparison
If you’re used to a Twin Cam, the Milwaukee-8 takes slightly more oil. Our Harley-Davidson engine size chart covers displacement comparisons across all Big Twin families, but here’s how oil capacity stacks up specifically:
| Engine Family | Years | Engine Oil (service change) |
|---|---|---|
| Twin Cam 96/103/110 | 1999–2016 | ~3.5 qt (3.3 L) — varies by tank config |
| Milwaukee-8 107 | 2017–present | 4.8 qt (4.5 L) |
| Milwaukee-8 114 | 2018–present | 4.8 qt (4.5 L) |
| Milwaukee-8 117 | 2019–2023 (CVO) | 4.75 qt (4.5 L) |
| Milwaukee-8 131 | 2022–present (CVO) | ~4.8 qt (4.5 L) |
If you’ve previously owned a Twin Cam and kept the 3.5-quart habit, you’re under-filling your Milwaukee-8 by more than a quart. This is one of the more common early-ownership mistakes our research team found across dozens of HDForums and Reddit r/Harley threads — owners simply applying their old engine’s capacity to the new motor.
For context on common Milwaukee-8 issues that can affect oil consumption and engine health, see our guide: Milwaukee-8 Years to Avoid.
Frequently Asked Questions
How many quarts of oil does a Milwaukee-8 take?
A Milwaukee-8 107 or 114 takes 4.8 qt (4.5 L) at a standard oil change with filter replacement. The dry fill (new system) is 5.0–5.2 qt depending on whether the bike is twin-cooled or oil-cooled. Always add 4.0 qt initially after a change, then check level hot before topping off.
Can I use SYN3 in a Milwaukee-8?
Yes — Screamin’ Eagle SYN3 Full Synthetic 20W-50 is the factory-preferred oil for all Milwaukee-8 engines. Per the service manual (Table 2-4), it carries the HD 360 rating and provides “Excellent” cold-start performance down to 30.2°F (-1°C). It is the top recommendation, above conventional HD 360 motorcycle oil.
What oil does the Milwaukee-8 131 take?
The Milwaukee-8 131 Screamin’ Eagle engine uses SAE 20W-50 synthetic oil — the same viscosity spec as all other Milwaukee-8 variants. Capacity is approximately 4.8 qt (4.5 L) at a service change. Confirm with your specific CVO model year owner’s manual, as Harley-Davidson may note adjustments for the larger displacement.
How often does a Milwaukee-8 need an oil change?
Every 5,000 miles (8,000 km) under normal conditions, per Table 2-1 of the HD Service Manual. The first change is at 1,000 miles for a new engine. In cold climates with frequent short trips under 15 miles, reduce to every 1,500 miles. Primary chaincase fluid changes every 10,000 miles; transmission every 20,000 miles.
Does the Milwaukee-8 use the same oil as the Twin Cam?
Same viscosity (SAE 20W-50), same HD 360 certification — but the Milwaukee-8 takes more of it. A Twin Cam typically uses around 3.5 qt versus the M8’s 4.8 qt service fill. Do not carry your old Twin Cam quantity habit to the Milwaukee-8 or you risk running under-filled.
Is the primary chaincase oil the same as engine oil on a Milwaukee-8?
No. The Milwaukee-8 runs three separate fluid compartments. The engine takes SYN3 or HD 360 motor oil. The primary chaincase and transmission both use HD FORMULA+ Transmission and Primary Chain Lubricant. Mixing motor oil into the primary or SYN3 into the transmission can damage clutch function and gears. The service manual explicitly warns against mixing mineral-based lubricants with SYN3 in the transmission.
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