There are so many things to juggle in combustion theory: lower temperatures mean less Nox, but higher temperatures mean greater efficiencies and higher torque.

With Hydrogen augmentation and other helps, the fuel ratio can be pushed far past stoicoimetric and still keep a fast enough burn rate/mixture, but when past stoiciometric the temps drop off again, reducing Nox and getting better mileage at the same time because it's way leaner than normal. There are people doing this on the sidelines now.

The sooner we go electric, the sooner all that complicated juggling and polution control in the I.C.E. will be done away with. I guess this EGR cooler is a good thing in some ways, but I just look forward to the day when it will be obsolete.

Wasn't EGR the technique that mechanics so adored about 1970 - you drove an hour, the mechanic worked two hours, then you could drive another hour. It worked so well everyone abandoned it.

This is undoubtedly far superior and all computer controlled so nothing will go wrong, go wrogg, gno rwonk...

Umm... no. EGR is still widely used in tons of cars today. You just don't hear about it because it's reliable enough that no one even knows it's there any more. Besides, as the article states this is mainly for diesel engines which run ultra-lean by nature and also have extremely low exhust temperatures compared to gasoline, thus making EGR and turbochargers last longer and more reliable due to the lower heat exposure.

Raf- Only on recent vehicles with variable Cam timing capabilities on at least the Exhuast side omit EGR and induce reverse flow without the need for an EGR valve to pipe exhuast back into the intake manifold. Vehicles which still do not have the capability to adjust cam timing on the fly still use EGR valves and have a pipe connecting an exhaust port (and the exhaust manifold on older vehicles) directly to the intake manifold through a valve controlled by the ECU. EGR is used mainly during part load operation.

Virtually all gasoline engines use cooled EGR. It is blocked on heat-up, and on warmed up engine EGR rate goes to zero at idle and at full power. Thus draw backs of early EGR is eliminated. EGR reduces NOx generation by up to 30%, and three way cat is doing the rest. Additional benefit is slightly reduced fuel consumption at partial load (due to less pumping losses), but it is way less then 4-5% referred by Rafael. Passive EGR is not widely used, because remaining gas is hot and not so effective in NOx reduction, plus hot gases cause problems with engine wear and fuel consumption (relevant to diesel engines too). I had troubles with EGR too: on 2.5 l Mazda engine because of troubles with closed loop operation at full throttle engine worked with over rich mixture, and resulted soot clogged EGR valve. While fixing this problem, I doubled EGR as anti-theft device. Magnetically operated switch shorts EGR valve, and EGR stays open at idle and start-up. Engine immediately dies, and no computer diagnostic could reveal the problem.

On turbocharged diesel engine EGR is very complicated matter. Diesel exhaust contains soot, and if cooled exhaust gases are recirculated to air intake before turbocharger, soot/oil mixture precipitates on compressor blades, disbalances them, and resulted vibration destroys compressor. Because of that diesel engine manufacturers usually route exhaust gases (sometimes filtered) after turbocharger, but this requires very sophisticated control of turbocharger (usually done by variable geometry turbocharger). Interesting enough, appears that this fundamental problem disappears right now. Due to current extremely high requirements for soot emission from diesel engines, exhaust after properly working diesel particulate filter is virtually free of soot. Thus it is possible to use for recirculation this exhaust stream and feed it directly before turbocharger.

Diesels with EGR introduce SO2, water & Carbon (soot) back into the combustion chamber. Anytime you add sulfuric acid & dirt into an engine you limit its durability. Take the exhaust gas from AFTER the diesel particulate filter & eliminate the sulfur & soot. Variable valve timing is now standard on most diesels too.

Clearly, the problem is related to the proper regulation of hot air. A Harvey D./Broken Record tax on repeating the same tired mantra over and over about carbon taxes should make the hot air issue palatable for the general public.

My personal views of fuel cell transportation is that we depend on fuel to much.we need to reach out and find the next new thing to replace fuel ,its not hard its right in front of us , we just cant and dont want to find it.if you could fill your car up and it last you 30 days will that be remarkable.the tecnology is all around us if we stop bein greedy {corporat world} and stop pricing these car so hi ,and work together.if i had the money I would put my idea to work but until then goodluck ps work together

I'm not sure TRMC's new cooler would work on a big (6.0L+) diesel, the performance loss would be unacceptable to the American heavy duty diesel truck buyer -- you know how we are.