Hey, you got water in my fuel mixture. Hey, you got fuel in my water.

September 30, 2016 7:50 AM

New York Times: "For decades, automakers have relied on turbocharging, which uses energy captured from exhaust gases to force additional air into the cylinders, to increase the power and efficiency of some gasoline engines." "[Now] a prominent automotive supplier has developed a counterintuitive technology that could enhance turbocharged engines for passenger cars by improving fuel economy with no reduction in power. How? By spraying water into the cylinders as the engine is operating." Warning: Some marketing speak in quotes.
posted by mr_bovis (37 comments total)

It's not exactly novel - as I recall, water injection was at least somewhat common in WWII aircraft piston engines.
posted by wotsac at 7:55 AM on September 30, 2016 [10 favorites]

wotsac, it was still well-known in the 1950s:

The rainwater blowin' all under my hood
I know that I was doin' my motor good
- Chuck Berry, Maybelline, 1955
posted by tommasz at 8:04 AM on September 30, 2016 [13 favorites]

Even the article itself acknowledges that this is nothing new:

It is not a new concept. Water-injection technology came to prominence during World War II, when it was used to enhance the performance of supercharged, piston-powered fighter planes during takeoffs and strenuous combat maneuvers.

Water injection made another appearance in one of the first turbocharged production cars, the 1962 Oldsmobile Cutlass Turbo Jetfire, where, instead of the sophisticated antiknock sensors that are standard equipment in modern cars, a mixture of water and methanol was added to the air-fuel mixture to control combustion.

Water injection appeared again in the 1980s in some turbocharged Formula One cars, which did much to burnish turbocharging’s public appeal.

It's not clear what this article is, other than a marketing piece for Bosch and BMW.
posted by indubitable at 8:06 AM on September 30, 2016 [7 favorites]

Mad Max Fury Road also includes some prior art in this area.
posted by paper chromatographologist at 8:15 AM on September 30, 2016 [3 favorites]

Meanwhile, BMW continues to wring its hands over electric cars.
posted by selfnoise at 8:18 AM on September 30, 2016

OK great so we're reducing usage of the second most valuable liquid on Earth by using more of the first most valuable liquid?
posted by EndsOfInvention at 8:30 AM on September 30, 2016 [2 favorites]

I more cynical take would be looking at how the water tank is serviced.. VW did the diesel programming scandal for many reasons, but one was to not have to have a tank of urea in the car that needed periodic refilling (at service intervals). Though I'm sure you can DIY the refill (urea, water, etc), a cynic would see this as an extra revenue stream for dealers -- a standard charge and mandatory maintenance action.
posted by k5.user at 8:36 AM on September 30, 2016

Water injection was also extensively used to boost power in early jet engines. One side-effect was huge quantities of black smoke when it was turned on (the Wikipedia article has a nice photo illustrating just how much of a cloud a four-engine jet could produce). The article didn't mention this. I wonder if they'll have to add a particulate filter (with its associated problems) like they do with some diesel engines.
posted by penguinicity at 8:40 AM on September 30, 2016 [1 favorite]

...improving fuel economy with no reduction in power...

We have heard all this before, but it hasn't really panned out.

My wife's car is arguably one of these and I believe it is the first and only car I've ever used that wasn't able to easily surpass (or even equal) the manufacturer's EPA highway mileage estimate on a long trip.
posted by Western Infidels at 8:41 AM on September 30, 2016

a tank of urea in the car that needed periodic refilling

Mercedes 'Bluetec' is code for 'pee tank'. (Wiki: Diesel Exhaust Fluid)
posted by snuffleupagus at 8:41 AM on September 30, 2016

... using more of the first most valuable liquid?

Is this a joke? Water that gets injected into an internal combustion engine doesn't get used up.
posted by Bruce H. at 8:42 AM on September 30, 2016 [2 favorites]

Neither does water injected into humans, in that sense of "used up."
posted by snuffleupagus at 8:42 AM on September 30, 2016

OK great so we're reducing usage of the second most valuable liquid on Earth by using more of the first most valuable liquid?

Water is not consumed by this method, it just goes back into the cycle. You have to factor in the carbon footprint of recovering that water, however. It seems very likely to be a net gain in efficiency, on the face of it.
posted by howfar at 8:45 AM on September 30, 2016 [1 favorite]

Speaking of Formula 1, the more recent news is TJI, the latest F1 tech that seems likely to eventually make its way into road cars.
posted by sfenders at 8:50 AM on September 30, 2016

Flyin' Coal
posted by tclark at 8:56 AM on September 30, 2016

Water injection has been a particulate reduction and NOx technology in diesel engines for a while now. In the world I live in, it's primarily seen as a way of knocking down air pollutants and reducing smog, rather than an efficiency booster.

There's a decent review of the technology here.
posted by bonehead at 8:58 AM on September 30, 2016

If the water came from a potable source and becomes vapor or drips onto a dusty road, aren't we turning it into dirty water that's super expensive to make potable? The article says it already needs distilled water, so unless someone makes a magic engine that can handle minerals and gross stuff in grey water, this could be a lateral move ecologically.
posted by MuppetNavy at 9:04 AM on September 30, 2016 [1 favorite]

Water injection was also extensively used to boost power in early jet engines. One side-effect was huge quantities of black smoke when it was turned on (the Wikipedia article has a nice photo illustrating just how much of a cloud a four-engine jet could produce). The article didn't mention this. I wonder if they'll have to add a particulate filter (with its associated problems) like they do with some diesel engines.

The problem with jet engines is that there's a constantly flame and injecting water quenches the flame temperature and causes incomplete combustion.

Piston engines are usually running with extreme amounts of excess heat on their power stroke. Even if you inject water or emulsify it along with the fuel you'll still get the same level of combustion (you still have the required amount of heat, your limiting factor is usually O2) without water in the mix. In fact you'll probably get better combustion because you can run the mixture way leaner without having to worry about NOx forming.
posted by Talez at 9:09 AM on September 30, 2016

Hobbyists (read: "street racers") have been doing this for a while, too.

http://www.turbomirage.com/water

A friend of mine did it to his Miata in ~2004 or so; repurposing the windshield washer fluid tank.
Worked fine. I dunno about any "fuel savings" per-se, but it could develop more power.
posted by Xyanthilous P. Harrierstick at 9:32 AM on September 30, 2016 [1 favorite]

If I remember correctly, some of the early Turbo Saab road cars used water injection.
posted by Burn_IT at 9:49 AM on September 30, 2016

Is this technology the glimmer of truth behind the "I invented an engine that will run on water but Big Oil is suppressing it" crowd?
posted by mr vino at 9:53 AM on September 30, 2016 [1 favorite]

I went down the water injection path when I was up to my elbows in my own turbo project ten years ago. It isn't a magic bullet, but it does a few things exceptionally well. The trick is to use it properly and judiciously - you aren't putting out a fire so much as stabilizing the in-cylinder environment so it can withstand more pressure and more heat and prevent your fuel mixture from spontaneously detonating. And yeah, a little bit of atomized water vapor at **exactly** the right time will do all that.

One downside to water injection is that water becomes another under-hood consumable to manage and refill as necessary. I had some tricky safety measures in place in mine to give me some protection if I ran out of water or the mechanism failed, but even the really good system I used (Aquamist) had a huge dose of Rube Goldberg in it.
posted by mosk at 10:20 AM on September 30, 2016 [3 favorites]

Hobbyists (read: "street racers")

Or, you know, the vastly larger number of people who race legally on closed courses who are not criminals.
posted by indubitable at 10:27 AM on September 30, 2016 [1 favorite]

Yeah, this is already a common thing with modified turbo cars. My roommate did it to his 300ZX when he installed a larger turbo. Depending on where you live and the season, you need to mix a decent amount of methanol in to prevent the water from freezing.

It's not new technology in any sense, but as mosk mentioned, it could do with some oem manufacturer polish wrt system reliability, etc.
posted by ryanrs at 11:51 AM on September 30, 2016

I worked on a race car in the early 1990's (Sierra Cosworth) that had about 500hp (Race car) and we made up a little system for water injection that certainly helped power and definitely helped with temperature control in the engine. It is really easy to do. When we were proving the concept, we just put the windscreen washer pump onto a push button and stuck a windscreen washer nozzle into the intake. Enough to work out what was going on and see it was worth pursuing. Our limitation was the valves melting and weird pre-ignition issues because of the vast heat we were producing, so it calmed everything down and allowed us to hold the high power levels reliably and tune accordingly.

In the world I live in, it's primarily seen as a way of knocking down air pollutants and reducing smog, rather than an efficiency booster.

That entirely depends on your perspective. For a given (road) engine power, it reduces emissions, but if your ceiling is emissions in the first place (which it is in modern cars for the most part) you can offer a more powerful engine for the same pollutant level. So... like I say. It depends where you are looking at it from.
posted by Brockles at 11:58 AM on September 30, 2016 [6 favorites]

Speaking of Formula 1, the more recent news is TJI, the latest F1 tech that seems likely to eventually make its way into road cars.

Huh. That's a very similar concept to the pre-combustion chamber used on diesel engines 30 or more years ago. Mercedes in particular had a great little system that an aircraft engine I was involved with used for a while. Interesting that it is now being used in petrol engines.
posted by Brockles at 12:02 PM on September 30, 2016

The increasing complexity of internal combustion engines reminds me of the hugely complicated aircraft engines towards the end of WWII, such as the Napier Nomad and the Wright R-3350 Duplex-Cyclone - powerful and efficient but ultimately replaced by much simpler jet turbines.

As EVs start taking market share, the development cost of these engines is going to continue going up while being spread out over fewer and fewer vehicles. Eventually there will be a tipping point where it's simply not possible to develop and build the next generation while making a profit.
posted by Harvey Byrd at 12:12 PM on September 30, 2016 [1 favorite]

Why couldn't water (used and also generated as a combustion product) be condensed and re-distilled out of the car's own exhaust? I'm sure there is a thermodynamic explanation, but it's not my area. We've got both waste heat for distillation and noise that could be used for thermoacoustic cooling.
posted by qbject at 12:13 PM on September 30, 2016

Crower cam six cycle hybrid internal combustion steam engine.
posted by hortense at 12:38 PM on September 30, 2016 [1 favorite]

It is pretty easy to add water injection to a turbo engine. When I was running a 20+psi 2.5l in my Caravan I added water injection when I added extra fuel fuel injectors. The water injectors would come on at the same time as the fuel injectors as boost rose to help cool the charge and prevent the engine from exploding. So more power for longer.


k5.user: "I more cynical take would be looking at how the water tank is serviced.. VW did the diesel programming scandal for many reasons, but one was to not have to have a tank of urea in the car that needed periodic refilling (at service intervals). Though I'm sure you can DIY the refill (urea, water, etc), a cynic would see this as an extra revenue stream for dealers -- a standard charge and mandatory maintenance action."

You go through a lot more water than you'd be wanting to traipse to the dealer for. Even Urea is stocked at many service stations along with the oil and windshield washer fluid. Distilled water is like $3 for 19L in the big blue jugs at my local supermarket. Or in a more consumer friendly version it's $2 for a 4l milk style jug at the drug store. If the system becomes popular I'd bet name brand turbo fluid (already mixed with methanol) would appear in the same place.
posted by Mitheral at 1:16 PM on September 30, 2016 [1 favorite]

OK great so we're reducing usage of the second most valuable liquid on Earth by using more of the first most valuable liquid?

End-stage capitalism looks like Ouroboros, apparently.
posted by a lungful of dragon at 1:59 PM on September 30, 2016

That entirely depends on your perspective.

Big marine---ship and ferry---engines in this case. It was a tech demonstrator project a few years ago.
posted by bonehead at 2:14 PM on September 30, 2016

I did this once in Florida and it did not improve performance. I think the key is using small amounts of water, not a 5-foot puddle after a tropical storm.
posted by RobotVoodooPower at 2:19 PM on September 30, 2016 [2 favorites]

1962 Oldsmobile Cutlass Turbo Jetfire

I thought macho-word-salad product names were a more recent phenomenon than that, but I guess not.
posted by mhoye at 6:40 PM on September 30, 2016

That's not the half of it. Two of those words are actually feature descriptions. Compare to something like the Dodge Custom Royal Lancer. In '58 available with the Ram Fire engine (replacement for '57s Super Red Ram) or D-500 Hemi. Or you could get the no name 361 equipped with Electrojector EFI.
posted by Mitheral at 8:42 PM on September 30, 2016

Back in the '60s when the early Boeing 707's with the water-injection systems (We called them 'aquajets' around the airport) were still common, in still air the tower would sequence the aquajets at the rear of the takeoff queue due to them reducing the RVR to approximately zero.

[RVR=Runway Visual Range, or how far down the runway you can see from the cockpit.]
posted by pjern at 9:52 PM on September 30, 2016 [1 favorite]

Is this a joke? Water that gets injected into an internal combustion engine doesn't get used up.

Internal combustion engines are, in fact, net producers of water.

They take hydrogen that’s been trapped underground for epochs and create nearly as much H₂O as the laws of chemistry allow.

Unfortunately, they do a similar thing with carbon.
posted by Fongotskilernie at 1:35 AM on October 3, 2016