Heritage — The Original AOS

The air/oil separator was invented here. Every EJ car still needs one. We still make the original.

Built in-house

Engines assembled at our East Coast facility. Parts designed, tested, and proven on our own cars — including the Gymkhana builds.

Support from the builders

Questions go to the people who made the part, not a call center. Contact us — a real person answers.

Backed in writing

Engines carry 1 year / 12,000 miles. AOS carries a limited lifetime warranty. Extended engine coverage is available.