Skip advert
Advertisement

This is how to make your M135i sound like an M4

This M135i owner hacked into BMW's synthesised system to make his car sound like a 425bhp M4

Whether we like it or not, the practice of synthesising engine noises is becoming increasingly common in new performance cars. Sticking a turbocharger into the exhaust pathway and improvements to sound proofing have lead to a significant decrease in engine noise, much to the disappointment of many enthusiastic drivers. To claw back some of that aural involvement, manufacturers have resorted to this controversial system.

BMW's synthesised engine noises are played into the cabin through the car's speakers, so in theory, disconnecting your speakers should remove their influence altogether. But it was only a matter of time before someone went a step further and actually modified the synthesised sound.

Advertisement - Article continues below

>Read - BMW M135i review and pictures

In this case, a tech-savvy M135i owner has managed to hack into his system and upload the soundtrack used in the new M4. It swaps the typically smooth straight-six soundtrack for a rougher, harder voice. You can hear it in the video above.

>Read - BMW M4 review, price and specs

If you want to listen to the M135i with its factory fitted synthesiser working, watch our track battle video below. What do you think? 

Skip advert
Advertisement

Recommended

BMW M135 v Mercedes-AMG A35 – which is the best £50k hot hatch?
A35 v M135
Group tests

BMW M135 v Mercedes-AMG A35 – which is the best £50k hot hatch?

BMW’s M135 xDrive has found some much‑needed focus with its new M Dynamic Pack, but is it enough to give it the edge over Mercedes‑AMG’s A35?
11 Jan 2026
BMW M135 xDrive review – all-wheel drive hot hatch eyes Audi S3
BMW M135 xDrive
In-depth reviews

BMW M135 xDrive review – all-wheel drive hot hatch eyes Audi S3

The M135 has lost an ‘i’ and gained chassis revisions and a restyle. Is it enough to make it a benchmark hot hatch?
4 Dec 2025
Skip advert
Advertisement

Most Popular

Porsche confirms no electric 911 as it revises product plans
Porsche 911
News

Porsche confirms no electric 911 as it revises product plans

As it works through one of the toughest patches in its history, Porsche announces an action plan designed to revive its lineup
24 Jun 2026
Fiat Grande Panda review – as cool as a Renault 5 but with petrol power
Fiat Grande Panda front
Reviews

Fiat Grande Panda review – as cool as a Renault 5 but with petrol power

Fiat’s take on the retro-modern small car has substance and talent to match its style
22 Jun 2026
McLaren MSO HS: the secret 205mph special born to save the brand
McLaren MSO 688 HS
Features

McLaren MSO HS: the secret 205mph special born to save the brand

This could just be the best McLaren you’ve never heard of. We get the inside story on the ultra-exclusive, 675LT-based MSO HS
21 Jun 2026