BMW Z4 35i - N55

E89 (2009–2019) · 306 hp

Stage 1

E85

E85 + Stage 1

	Original	After tuning	Diff
Power hp	306	365	+59
Torque Nm	400	520	+120

Power gain

+19%

Torque gain

+30%

Ready to feel these +59 hp on the road?

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

Order tuning file →

Stage 1 file from €85

Exact price depends on the ECU — confirmed when you upload the file

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

Power graph / Stage 1

PowerTorqueStock

	Original	After E85	Diff
Power hp	306	320	+14
Torque Nm	400	420	+20

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 €2 155 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 −47%

Petrol · 100 km

~~14.3 L~~ · €30.3

E85 · 100 km

17.5 L · €15.93

You save ≈ €14.37 every 100 km — about €2 155 a year (over 15 000 km)

E85 uses ≈ +23% more litres, but the pump price (€0.909/L vs €2.122/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	306	395	+89
Torque Nm	400	570	+170

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.

+89 hp and €2 155/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 −47%

Petrol · 100 km

~~14.3 L~~ · €30.3

E85 · 100 km

17.5 L · €15.93

You save ≈ €14.37 every 100 km — about €2 155 a year (over 15 000 km)

E85 uses ≈ +23% more litres, but the pump price (€0.909/L vs €2.122/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 →