You might have seen the “Efficient Performance” logo on our website when looking at AC Schnitzer performance upgrades.
What do we mean by this? This logo represents AC Schnitzer’s commitment to increasing performance “without compromise” to daily driving. This includes the area of emissions. We’ve all seen poorly tuned cars emitting black smoke on acceleration, but this is not necessary. The power output of a vehicle can be increased without making emissions worse – in fact the specific emissions (CO2 per HP) can go down.
Here is an example. This X3 M 40i has the B58 engine, which is shared with many other models.
You can see that the performance of this car has been substantially improved. The 0-60mph (0-100km/h) time is just two tenths of a second quicker, but once rolling the AC Schnitzer tuned car is a healthy two seconds quicker in every other test. This equates to safer overtaking and even more driving pleasure.
Now look at the CO2 figures. The result, according to the latest WLTP / Euro 6d temp test, is that emissions are the same as the standard car. That’s efficient performance from AC Schnitzer!
AC Schnitzer have been tuning BMWs and MINIs for over 30 years. Early efforts included big-bore engines with wild cams and even superchargers bolted on. Things have moved on, but the subject of performance upgrades is still one that takes up more of our time when talking with customers than any other. The bewildering range of terms used (remaps, chips, flashes, tuning boxes…), the technical differences between them and the pros and cons of each tuning method is enough to make your head spin. Then there are the warranty implications to consider. Oh dear!
Thankfully, AC Schnitzer offer a clear upgrade path that won’t cause you any sleepless nights. It’s not for everyone, as we’ll see in a moment, but for many BMW and MINI owners there is no better choice than AC Schnitzer.
“I’ve seen AC Schnitzer upgrades advertised – they are expensive!”
It’s fair to say that we hear this comment often, and we’re aware of course that there are many less expensive alternatives out there. But there are sound reasons behind this. Let’s take a look at them.
Worldwide, many AC Schnitzer dealers are also BMW dealers. AC Schnitzer is owned by the Kohl BMW Group. So AC Schnitzer aim their product range at new and nearly new cars (under 3 years old). All AC Schnitzer upgrades must meet the following requirements:
The upgrade must not alter the vehicle software
The performance increase must be safe and legal, for you and for the car
The power delivery characteristic must be like standard
There must be no change to servicing and diagnosis procedures
The car must still meet all emissions requirements
The engine components and drivetrain must still be covered by warranty.
“Can’t I just get a re-map?”
Leaving aside the highly variable quality of software tuning (re-maps) on the market, AC Schnitzer upgrades are always made with hardware. This means an extra engine control unit (ECU) mounted in the engine bay to take care of the tuning duties. AC Schnitzer don’t offer tuning via software because this can affect the car’s warranty, and also means that if BMW needed to apply a service update that software could be overwritten. BMW check your car every time it visits the dealer to see if the software has been altered from standard. Inconvenient, at best. At worst, a major warranty claim could be denied.
“So it’s an expensive tuning box then.”
In a way, yes, but a sophisticated one. Unlike some tuning boxes which simply manipulate boost sensor or fuel pressure information to increase power without any safety checks, or allow the owner to flip dip-switches without knowing what they are getting into, the AC Schnitzer control unit is developed to be safe for anyone to use. On a brand new car, from day one. To prove it, AC Schnitzer warrant the engine and drivetrain for 3 years – the same as the BMW warranty.
To enable this the control unit (in most cases) connects to the CANBUS system on the car which carries all the sensor information. It constantly monitors channels like boost pressure, exhaust gas temperature (EGT), injector duration and many other inputs, to make sure that the performance increase is being delivered in a safe way. The full power increase is only available when the engine is fully warmed up, and running on the recommended fuel (98 octane on petrol engines). We can only give an engine warranty by tuning the car in this way.
“Tell me more about this warranty.”
All AC Schnitzer performance upgrades include a warranty that runs alongside the BMW factory warranty from the date of first registration. In the UK, this is for the first 3 years of the car’s life. The warranty stays with the car, not the owner.
There are conditions. Read more about them here. But in essence this warranty is the best available in the tuning world. It’s designed to cover any faults arising from the tuning that BMW won’t cover. In most cases an engine fault will be unrelated to the tuning and will still be rectified under your BMW warranty, but should you need it we can step in. AC Schnitzer in Germany will help diagnose and rectify the problem and our network of friendly BMW and independent dealers will help too.
“My car is 5 years old, what now?”.
We may still be able to offer tuning, but we can’t warrant the engines on older cars, sorry. Please contact us for advice.
“I want to buy/move/sell a used AC Schnitzer upgrade – what happens with the engine warranty?”
Contact us with details – we may be able to help with warranty in these cases.
AC Schnitzer performance upgrades are the best option for new and nearly new cars. They cost more than other tuning products because they are the best developed, from the best BMW tuner, with the best warranty.