B58 Gen 1 · 3.0 single-turbo inline-six
The original B58 is the engine that earned the legend: BMW's 3.0-litre single-turbo straight-six in the M140i, M240i, 340i and 440i. It is one of the most rewarding cars on the road to tune, with a big, safe ceiling on stock internals.
B58 Gen 1 vehicles
SamuelTuned covers B58 Gen 1 tuning and remapping across the BMW M140i (F20 / F21), BMW M240i (F22 / F23), BMW 340i (F30 / F31) and BMW 440i (F32 / F33 / F36). Each one gets a custom, individually-calibrated remote ECU remap — Stage 1, Stage 2 and Stage 3. Open the configurator on your car to choose your stage, add the options that fit, and send the full build to Samuel.
Engine guide
The Gen 1 B58 turned warm hatches and saloons into genuine performance cars, and it has a deserved reputation for taking power. A custom Stage 1 alone takes the M140i and friends from quick to seriously fast, holding boost the factory map leaves on the table, with sharper response and a transmission tuned to match.
These cars are now well used, and condition, fuel and supporting mods vary widely. Samuel calibrates each B58 Gen 1 to your datalogs rather than flashing a generic file — the safe way to extract the full gain, especially on higher-mileage cars and E85 builds.
Stage 1 is software only. Stage 2 adds a downpipe (OPF delete where applicable) and intake. E85 flex is the standout upgrade for the money. The stock turbo will eventually limit you, and a hybrid turbo opens up 500+ bhp territory with the right fuel and a fully bespoke map.
Tune stages
Stage 1
~400–430 bhp
Software only on the stock turbo. Transforms the car.
Stage 2
~460–490 bhp
Downpipe + intake. Bigger, sustained delivery.
E85 flex
500+ bhp
Flex-fuel kit + ethanol map — the best value gain on the B58.
Hybrid turbo
Quoted per build
Upgraded turbo + supporting fuel. Bespoke calibration.
Figures are indicative and depend on the exact model, fuel and supporting hardware. Every tune is calibrated individually — open the configurator for your car for the precise build and price.
FAQ
A custom Stage 1 on the B58 Gen 1 M140i typically lands around 400–430 bhp on quality pump fuel — a big step over the ~335–340 bhp standard, with no hardware needed.
Yes, when calibrated properly. Samuel tunes from your datalogs and to your fuel, keeping timing and boost in a safe window — which is exactly why a custom map beats a generic OTS file on a used car.
Bootmod3 and MHD both fully support the Gen 1 B58. Both are flashed remotely; Samuel recommends the right one for your goals.
Most Gen 1 B58 cars don't, but some later production DMEs are locked. Samuel will confirm from your VIN and arrange the unlock if it's required.
Keep exploring
Platform
Our primary flash platform for B58 Gen 1 builds: app-driven, OTA custom map delivery.
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The established mobile-app flasher, strong across B58 Gen 1 and turbo BMW builds.
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