BMW Z4 M40i

G29 (2019–2023) · 340 hp

Stage 1

E85

E85 + Stage 1

	Original	After tuning	Diff
Power hp	340	420	+80
Torque Nm	500	620	+120

Power gain

+24%

Torque gain

+24%

Ready to feel these +80 hp on the road?

Get your ready-to-flash Stage 1 file for the BMW Z4

Order tuning file →

Stage 1 file: €120

✓ Original file back-up ✓ Delivered in ~30 min ✓ Support included

Power graph / Stage 1

PowerTorqueStock

	Original	After E85	Diff
Power hp	340	355	+15
Torque Nm	500	525	+25

E85 adaptation (no Stage 1)

Just the fuel switch: the ECU is adapted to run Superéthanol E85 (up to 85% bio-ethanol) with no Stage 1 chip on top. You get a small power bump from ethanol's higher octane (~104 RON) and a much cheaper fill-up. Flex Fuel file: the car still runs on regular petrol whenever you want.

Save €2 284 a year at the pump

Get your E85 adaptation file for the BMW Z4

Order tuning file →

File from €100

✓ Original file back-up ✓ Delivered in ~30 min ✓ Support included

Fuel cost — E85 vs petrol −45%

Petrol · 100 km

~~15.9 L~~ · €33.68

E85 · 100 km

20.3 L · €18.46

You save ≈ €15.23 every 100 km — about €2 284 a year (over 15 000 km)

E85 uses ≈ +28% more litres, but the pump price (€0.909/L vs €2.123/L, France average on October 29, 2026) more than makes up for it.

🇫🇷 Version française : conversion éthanol E85 de la BMW Z4, calculateur d'économies par département →

	Original	After E85 + Stage 1	Diff
Power hp	340	455	+115
Torque Nm	500	655	+155

E85 + Stage 1 remap

Chip tuning re-optimised for Superéthanol E85: the ignition and boost maps are calibrated to make full use of ethanol's higher octane (~104 RON). Bigger power and torque gains than either Stage 1 on petrol or E85 adaptation alone, plus the same cheap fill-up.

+115 hp and €2 284/year saved — both

Get your E85 + Stage 1 file for the BMW Z4

Order tuning file →

File from €100

✓ Original file back-up ✓ Delivered in ~30 min ✓ Support included

Fuel cost — E85 vs petrol −45%

Petrol · 100 km

~~15.9 L~~ · €33.68

E85 · 100 km

20.3 L · €18.46

You save ≈ €15.23 every 100 km — about €2 284 a year (over 15 000 km)

E85 uses ≈ +28% more litres, but the pump price (€0.909/L vs €2.123/L, France average on October 29, 2026) more than makes up for it.

🇫🇷 Version française : conversion éthanol E85 de la BMW Z4, calculateur d'économies par département →

Original ECU files for BMW Z4 Stock (ORI) files of this model · €20 per file →