Hey kids! Wanna convince Mom and Dad that the family sedan really needs that new high-flow exhaust you’ve been eyeing? It’s simple – tell ‘em it’ll help boost mileage and fuel efficiency! It’s true – performance upgrades like a new exhaust and water injection system not only add ponies, but increase mpg as well. And according to Autocar, that’s exactly the logic Bosch is using as it plans to install its water injection system on more models by 2019.

Using water injection for better internal combustion is nothing new, but the latest high-visibility application of the tech is on the BMW M4 GTS, a track-ready two-door that’s quite obviously focused on performance above all else.

Bosch, a German-based multinational auto parts supplier, is the company behind the Bimmer’s water injection system, and reports a 5-percent increase in horsepower, a 13-percent increase in fuel efficiency, and a 4-percent drop in CO2 emissions when its in use.

“The system works best on cars with an output of more than 80 kw (107 horsepower) per liter,” Fabiana Piazza, global project manager at Bosch, told Autocar. “We’re launching it into the market now as tighter legislation and new real driving emissions tests are increasing the importance of this technology in all cars.”

“We are in contact with major automotive makers already, but we can’t talk about them in more detail at this stage,” said Martin Frohnmaier, Bosch project lead. “We can say that we expect the system to make mass production from 2019.”

Autocar

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I totally agree with Ms. Piazza when she says that new regulations concerning emissions and fuel efficiency will force automakers to take a hard look at technology like the Bosch water injection system. Go ahead and call it a gimmick, if you want – fact is, automakers will be scrambling for every mpg possible in the next decade, and a few percent here and there can make all difference if it means avoiding costly fines.

What’s more, it’s entirely likely we’ll see the Bosch water system used heavily across BMW’s model lineup, given the Bavarian’s position as a major co-developer of the tech. Look for it to go large-scale soon.

My personal opinion? It all seems a bit silly, to be honest. If anything, it’s a band-aid solution that won’t have any real effect on mpg or emissions. The true innovations in this space are still in development – Honda’s plans to create engines with different-sized cylinders is a good example, as is the proliferation of hybrid technology. Meeting mileage and emissions goals is gonna take much more than just a glorified sprinkler system.

There’s another issue at play here – how often will consumers actually keep the water injection tank topped off? With such meager gains, it’s more thank likely most drivers won’t notice when the system stops working, further cementing this system as more of a gimmick than a real mpg solution.

But hey – if it means BMW can continue to make cars like the M4 GTS, then give me all the sprinkler systems.

How It Works

Water injection is relatively simple. Essentially, the technology introduces an ultra fine mist of distilled water into the combustion chamber prior to the ignition of the air/fuel mixture. The mist soaks up some of the heat, cooling the chamber, while also increasing the density of the air/fuel mix. The result is a reduction in pre-ignition and detonation (alternately called “knock” or “pinging”) and an increase in efficiency.

Long story short – more power, less waste.

The Bosch system on the M4 utilizes a 5-liter tank of distilled water located in the trunk, which Bosch says needs to be refilled on average every 1,800 miles. If the tank runs dry, the engine management will adapt to run with less output and lower efficiency until the tank is refilled.

One potential issue is the system’s use in colder climates, where the water can freeze. According to Autocar, Bosch is looking into using a heating system to prevent freezing.

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Read our full review on the BMW M4 GTS here.