G-Chassis · G02

G02 Tuning

BMW's X4 xDrive30i, X4 M40i, 2018–2025. Powered by the B48/B58 engine family.

Stage pricing for the G02

Stage 1
Tune
$495

Where every build starts. Calibration only.

Build this stage Stage 1 methodology
Stage 2
Tune + Supporting Hardware
$2,185

Cooling, downpipe, fueling — the ceiling worth chasing on factory turbos.

Build this stage Stage 2 methodology
Stage 3
Tune + Full Hardware Path
$4,255

Bigger fueling, often a hybrid or Phantom turbo. Per-car.

Build this stage Stage 3 methodology

The G02 X4 is the G01 X3 with the coupe-SUV roofline — same compact-SAV platform, same engines, traded for the lower fastback look. The M40i runs the B58 (around 382 hp in US trim), the xDrive30i the B48 four (252 hp), both tuning as they do in the X3 (full story on the G01 and G20 pages).

What you give up is a little rear headroom and cargo; what you get is the sportier silhouette on the same willing six. Honest notes are the familiar B58/B48 items (the oil-filter-housing gasket; G20 page).

So the G02 is the style-first compact SAV: X3 capability, swept-roof shape.

Parts that fit the G02

DR Forged wheels for the G02

Custom, made-to-order forged wheels — built to your car's spec, so any of them fits the G02. Pick the look; we build the fitment.

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Tech essays for the G02

Upcoming events

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Set the G02 as your garage vehicle and the rest of the store filters to what fits it.

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ANSWERED

Before you tune.

Will my dealer flag the tune at service?

The bootmod3 flash is non-destructive and reversible. Revert to stock before a dealer appointment and the ECU is back to factory in a few minutes; re-flash after service. We document the revert step in writing so the next person opening your file knows what's there.

Is it safe for the engine?

Every tune we ship has been datalogged on the car it was written for. We look at knock counts, fuel trims, boost behavior, and intake temps before we sign off. If the numbers don't sit right, we revise. That review and the revision policy are built into what the tune costs.

How long until I have a working tune?

Most calibrations turn around in a few days. We log, review, and revise before anything ships — we would rather get it right than get it out fast.

Can I go back to stock?

Yes. bootmod3 supports a stock revert that returns the ECU to factory calibration in under five minutes. The flash is non-destructive — nothing in the BMW DME is permanently modified. Most owners revert before trade-in.