Dinan Cold Air Intake – BMW M240i / M340i / M440i (B58)

OVERVIEW

The M240i, M340i and M440i are impressive cars, but the factory intake doesn't convey it — a plain air box with a basic panel filter and an intake resonator that mutes the turbo and induction noise enthusiasts actually want. The Dinan carbon fiber intake replaces it with a semi-open system that flows 58% more air than stock, adding top-end power, sharper throttle response, a far more aggressive carbon fiber appearance, and noticeably more induction sound now that the resonator is gone.

Dinan reworked and enlarged the entire lower box to house a 40% larger free-flowing filter, adding a secondary inlet whose shape, size and location were extensively tested so the extra volume would not raise turbo inlet temperatures. The result is measured gains of up to 9 WHP and 8 lb-ft of torque on an otherwise stock vehicle, along with an audible turbo spool and blow-off event — a clear departure from Dinan's traditional fully sealed intakes.

SPECS

• Maximum gain of +9 WHP @ 6500 RPM on an otherwise stock vehicle (Dinan measured)
• Maximum gain of +8 lb-ft of torque @ 6000 RPM (Dinan measured)
• Outflows the factory intake by 58% or more
• Air box volume 60% larger than the factory box
• 40% increase in filter area: stock 82 in², Dinan 115 in²
• Carbon fiber air box lid and intake tube
• Semi-open design with secondary air inlets; factory intake resonator removed
• Compatible with G2x Mx40i models with and without factory strut bracing
• Dinan published installation time: 1 hour
• Emissions status per Dinan: "This product is NOT LEGAL FOR SALE OR USE IN THE STATE OF CALIFORNIA. Testing with the California Air Resources Board, in order to achieve 50-state compliance, is pending with CARB." No CARB EO number has been issued for this part.
• Dinan warranty: the remainder of the BMW new-car limited warranty (up to 4 years / 50,000 miles) or 2 years / unlimited mileage from purchase, whichever is greater; wear items, maintenance parts, improper installation and competition use are excluded

PARTS INCLUDED

• Dinan air box assembly
• Dinan high-flow air filter
• Carbon fiber air box lid
• Turbo inlet hose (model-specific variant)
• Carbon fiber inlet tube
• Brace spacer kit
• Hardware kit: 10 rivets, 6 fender washers, 3 nylok nuts, 3 button head screws (M4x16), 2 button head screws (M4x10) and 3 clamps

TECH RESOURCES

Additional Parts Required

• None. Dinan specifies no additional hardware for this part.
• Installer-supplied tools only, including a rivet gun for the supplied rivets.

Installation

• Dinan D760-0058 Cold Air Intake installation instructions (INS760-0058, Rev. C)

Notes

• M240i (G42) launched as xDrive-only for MY2022; a rear-wheel-drive M240i was added for MY2023. Both drivetrains are listed separately below with their correct start years — confirmed via BMW's own model-year press coverage, since Dinan's own listing title ("2022-2026 BMW M240i") doesn't distinguish drivetrain.

PART NUMBER

• D760-0058

VEHICLE APPLICATIONS