It has already happened. We now live in a world where big, powerful engines need MANY more gears than small engine, low powered cars. You can make big horsepower, with cats small enough to function in all mode/all load driving, but you dare not make it for long. The entire car design and engineering revolves around that catalytic converter, its operating range, and the specific warranty requirement. By controlling the exhaust volume (via gear selection when the throttle is open) you can choose how close the cat can be controlled (usually below that 1700-1800 F. danger zone.)
I am pretty sure that is part of the reason the new Tacoma V6 is SMALLER than the old engine, but there's always more than one reason for the changes.
As you can see, hybrid trucks are NOT going to happen until a magic catalytic converter is invented. Hybrids live and die by limiting cat size for quickest light-off interval. Some of them already have external heating sources to help initiate quicker light. The huge variation of "work" range (for trucks) means you will never see the job done with one tiny little cat. Multiple cats, with exhaust switching control, could work but the reliability of those switching components (added to very high initial parts costs) makes it a dead end. (I will add a truck/hybrid note at the end of this post).
Part of that protection method for cats is preventing big flow rate changes, such as repeated "throttle blip" downshifts (which explains why manual transmissions get harder and harder to choose from the options list.)
The trend to longer strokes, smaller bores, and more gears with less rpm will continue. We will never again have control of the throttle (except to offer our "vote" to the ECM, to take under "advisement".)
When I left the trade, we were looking very hard at how to turbo engines with cats, and make it work. When you do a long deceleration on a turbo, the exhaust heat (at the cat) goes away and doesn't come back instantly when the throttle is re-applied. The turbo really sucks up some heat, for a number of seconds (longer than EPA allows).
I have no idea how they are managing that problem, these days, but they have obviously worked it out. I suspect they are throwing a little fuel and throttle, with extreme spark retard and exhaust cam timing retard, to keep the turbo hot and somewhat spooled. I really don't know.....just guessing.... but that is where I would start if I was writing that particular section of code.
Every manufacturer has already been doing the "maintain some throttle/intake-exhaust flow" even after the customer lifts the throttle, to keep the cat happy. Every time you chop the throttle, in a repeated sequence at fairly short intervals, the cat temperature starts stepping up and holding (oddly enough). That is how the magazine testers manage to destroy the cat on a brand new road test car, within a day or two of picking it up from the manufacturer. I can tell you, I have had my share of sitting down with those fellows and explaining "how they broke it".
I sure am glad to be retired and done with all this stuff. The truth is, when you buy a new vehicle you are buying a product that works PRIMARILY to keep a catalytic converter alive, for a specified period, under the model target driving conditions of the model type design. With the popularity of big trucks and SUVs, I reckon my young friends I left behind....have all gone bald (men AND women) from tearing their hair out!
A note about the "hybrid truck" dilemma: Trucks can be really heavy, at times, or even tow heavy stuff. Electric motors are most efficient when you let them spin up pretty well, with pretty heavy rotating mass. Trying to couple those very large kinetic energies to drive wheels and loads that are bucking and bouncing down the road.....well....you get the picture. Add that particular issue to the problem of how to perform a panic stop with a good hybrid system, and you are really in a tough deal. True parallel Hybrids and electric cars can ONLY perform emergency ABS stops WITH the electric motor providing sufficient power to keep the wheels from actually stopping (during the brake pressure cycling events.) Should those electric motor armatures actually get stopped, during a panic stop, you won't get them to spin back up by simply releasing the brake pedal (objects in motion tend to stay in motion, objects at rest tend to stay at rest). The car would remain out of control and skidding. NOTE: the first prototype electrics we were testing, back in the 80s, were manual trans ONLY and the clutch pedal was REQUIRED to be depressed on every stop. Failure to do so took you out of the testing program.
Ok....probably bored everybody by now.
PS. Never underestimate those design engineers, at all the car companies. They figure out the impossible on a pretty regular basis!
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