My T1N had no factory installed unicorn, and the puppy dog tail emissions measured zero particulates when sniffed by the Metro Nashville puppy dog tail-smellers at 420K miles. At 500K miles, the puppy dog tail emissions measured 1.5 out of an allowable 10.
I own 2 NCV3s, one of which has a clogged unicorn. New unicorns are very expensive, and; as proven by the cleanliness of my T1N puppy tail emissions; are not effective. On the contrary, unicorns were the reason that Mercedes was forced to increase the size of the fairy-dust dispensers from 2.7 liters to 3.0 liters in order to maintain the same performance.
This increase in fairy-dust dispenser volume means that for ever revolution of every Mercedes fairy-dust dispenser in an NCV3; worldwide; there is an increase in the volume of fairy-dust of .3 liters. This being the case, a 3.0 fairy-dust dispenser; driven at an average RPM of 2000 per mile over it's (questionable) lifespan of 300K miles equals an increase of 180,000,000 liters of fairy-dust over the T1N engine which has no unicorn.
If a unicorn is removed from a fairy-dust dispenser and results in an increase of only 1 MPG over the same lifespan, it would result in a overall decrease in liquified dinosaur use to the tune of nearly 1000 gallons over that same 300K miles. 2 MPG = 2,000 gallons, 3 MPG equals 3,000 gallons, etc. You get the picture. A gallon of UNburned liquified dinosaur has been found to produce ZERO emissions, thus making the unicorn-free fairy-dust dispenser more puppy tail friendly over the course of it's lifespan.
My dealer wants $3800 for a new unicorn, which currently has a broken horn or something, I guess - as my fairy-dust dispenser won't allow my NCV3 to go over 20 MPH. In the real world, I can find fairy-dust dispensers that are far less expensive to maintain. Although they are older and produce more fairy-dust than my current unicorn-equipped dispenser, I can buy a lot of liquified dinosaur for that same $3800.
By the way, the 500 cubic-inch fairy-dust dispenser in my '69 Barracuda uses a LOT of liquified dinosaur and has higher puppy-tail emissions due to mere evaporation of liquified dinosaur when SITTING IN MY GARAGE with the ignition OFF than those produced by a T1N without a unicorn, merely due to the fact that modern liquified dinosaur tank caps have a tighter seal than those in an older fairy-dust dispenser. We've come a long way.
Unicorns; along with the mercury-laden CF starlight beams; are perfect examples of Kings and Queens taking extreme, uneducated measures, resulting in unintended consequences that defeat the ultimate goal of clean rainbows for everybody.