Sullair vs Atlas Copco Rotary Screw Compressors

The short answer: Atlas Copco wins on variable-speed-drive sophistication, on the most refined enclosure / sound dampening in the 5–25 HP class, and on integrated dryer / filter packages. Sullair wins on the simplicity and proven longevity of the Sullube oil-flooded airend, on a more straightforward service architecture, and on rugged jobsite-portable design (the Sullair 185 series is the U.S. construction-rental default). For a 5–25 HP fixed-speed shop rotary screw at a contractor price point, Sullair ShopTek is the better acquisition. For a 7.5–15 HP shop where variable demand and sound matter, Atlas Copco GA wins on operating cost and refinement.

The two oil-flooded screw specialists

Sullair (Michigan City, IN — owned by Hitachi Industrial Equipment Systems since 2017) built its reputation on the original North American oil-flooded rotary-screw airend, introduced in 1965. The signature engineering is the Sullube proprietary lubricant — a synthetic-blend coolant designed for 8,000-hour change intervals and the company’s own airend tolerance specifications. Sullair’s lineup that matters today: ShopTek (5–25 HP fixed-speed tank-mounted), LS-series (25–200 HP industrial), and the famous 185 / 375 / 750 portable series for construction.

Atlas Copco’s small-end rotary-screw line is the GA-series (5–700 HP), positioned as the global volume leader in industrial rotary screw. The GA’s signature engineering is the Atlas-Copco-designed 5/6 profile airend (oil-injected, not oil-flooded — there’s a difference) and the Roto-Xtend Duty lubricant. The same GA platform spans tank-mounted (GA5–GA11) all the way to base-mounted industrial (GA22–GA90).

Side-by-side at the 7.5 HP class

Spec	Sullair ShopTek ST510	Atlas Copco GA5-125
HP	7.5	7.5
SCFM	26 @ 125 PSI	28 @ 125 PSI
Tank	80 gal	71 gal
Lubrication	Sullube (oil-flooded)	Roto-Xtend Duty (oil-injected)
Airend	Sullair single-stage	Atlas Copco 5/6 profile
Drive	Direct-coupled	Direct or gear-coupled depending on variant
Cooling	Air-cooled	Air-cooled
Sound (dB(A) @ 1m)	~70	~68
Warranty	2 yr complete, 5 yr airend (Diamond)	5 yr airend (with fluid program)

Spec parity is close. The deciders are operational: lubricant change cost, controller sophistication, enclosure refinement, dealer network.

Where Sullair wins

• Sullube longevity. Sullube is a 30+-year-proven lubricant with documented 8,000-hour change intervals under standard operating conditions. The lubricant is monogamous to the Sullair airend — designed and tested as a single system. Many shops with 30-year-old Sullair LS-25 / LS-50 units still report zero airend failures.
• ShopTek simplicity. The ShopTek ST410 and ST510 are intentionally minimal — direct-drive, integrated controller, tank-mounted on 80-gallon ASME receiver. Fewer features means fewer failure modes. For job shops that don’t need variable-speed, this is the leanest legitimate industrial rotary screw.
• 185 portable workhorse. The Sullair 185 (185-DPQ-KUB) (185 SCFM at 100 PSI, Kubota Tier 4 Final diesel) is the U.S. construction-rental industry standard tow-behind. United Rentals, Sunbelt, Herc — they all stock 185 Sullairs. Parts availability is universal, operator training is universal, resale is strong.
• Service simplicity. Sullair’s airend service is documented in straightforward shop-manual format. Tolerances and torque values are published. Any HVAC/industrial service tech can be trained on a Sullair within a week. Atlas Copco GA service is more proprietary — software-locked Elektronikon updates and specific tooling.

Where Atlas Copco wins

• Variable-speed drive maturity. Atlas Copco’s GA VSD+ (and its PM motor drive technology) is the most refined VSD in the industry. At part-load (40–70% duty), it can reduce energy consumption by 30%+ vs the equivalent fixed-speed Sullair ShopTek. Sullair’s VSD offerings exist but the engineering depth doesn’t match.
• Integrated dryer / filter package quality. The “FF” (Full Feature) configuration on a GA-series ships with factory-engineered refrigerated dryer, particulate filters, and condensate drain integrated into the enclosure. The fit, finish, and serviceability is noticeably better than a comparable Sullair package.
• Elektronikon Touch. The GA-series controller is genuinely well-designed — full event logging, scheduled service alerts, network integration, multi-language. Sullair’s Air Logic / WS Controller is functional but more dated.
• Quieter at the same HP. GA-series enclosures are noticeably quieter at 5–25 HP — typically 2–5 dB(A) advantage at 1m. For shops with operators near the compressor room, this is meaningful.
• Global parts logistics. Atlas Copco’s parts depot network is the most extensive in the industry. Service parts for a GA-7 in 2026 ship from the same hub network as parts for a GA-7 in Singapore or Brazil. For multi-site facilities, this matters.

Recommended Sullair models

Sullair ShopTek ST410 (5 HP)

16 SCFM at 150 PSI on 80 gallons. Smallest stationary Sullair. Direct-drive, integrated controller, designed for general shop air.

Sullair ShopTek ST510 (7.5 HP)

26 SCFM at 125 PSI. Step up from the ST410 — same architecture, larger airend. The volume seller in the ShopTek line.

Sullair 185 T4F (185-DPQ-KUB)

185 SCFM at 100 PSI portable. Kubota Tier 4 Final diesel, tow-behind. The U.S. construction-rental default.

Recommended Atlas Copco models

Atlas Copco GA5 (7.5 HP)

28 SCFM at 125 PSI on 71 gallons. Direct competitor to ShopTek ST510. Integrated dryer optional, full Elektronikon controller standard.

Atlas Copco GA7 (10 HP)

41.6 SCFM at 125 PSI. Step-up. Same 5/6 profile airend at higher HP.

Atlas Copco GA11 (15 HP)

55 SCFM at 125 PSI. Mid-range industrial — solid choice for fab shops and small manufacturing.

Atlas Copco XAS 185 KD7

185 SCFM at 100 PSI tow-behind portable — Atlas Copco’s direct competitor to the Sullair 185. Same target market.

Common questions

Is “oil-flooded” the same as “oil-injected”?

Functionally similar, terminologically different. Sullair’s airend design floods the entire rotor chamber with lubricant; Atlas Copco’s GA airend injects oil into the rotor mesh under pressure. Both result in an oil-air mixture that’s separated downstream. Coolant volumes per CFM are similar; both require the same separator / filter architecture.

Which has better aftermarket parts pricing?

Sullair OEM parts are typically 10–15% less expensive than equivalent Atlas Copco parts in the U.S. aftermarket. Both have reasonable third-party alternatives for filters and oil, but using non-OEM lubricant voids airend warranty in both cases.

Is Sullair still made in the USA?

Yes. Sullair’s Michigan City, Indiana plant assembles ShopTek, LS-series, and 185 portables. Some components (motors, controllers) are sourced globally. Hitachi ownership has not changed U.S. assembly. Atlas Copco assembles small GA-series in Holyoke MA and Rock Hill SC for North American market.

How do warranty terms compare?

Sullair: 2 years complete unit, 5 years airend with Diamond service program. Atlas Copco: 5 years airend with active Roto-Xtend Duty Fluid program and authorized service. Both require OEM parts and lubricant to maintain extended warranty. Real-world warranty experience is similar.

Bottom line

Sullair is the no-frills, oil-flooded American screw compressor with the longest documented airend service history in the industry. Atlas Copco is the global benchmark for refined, energy-efficient industrial rotary screw with variable-speed leadership. For straightforward fixed-speed shop air, both are excellent — Sullair is typically the better acquisition price; Atlas Copco is typically the better operating-cost machine. Browse the full rotary-screw catalog to see additional models from each.