IMHO* Series – An interview with Zissis Samaras


*In My Humble Opinion, 5/1/15

On April 21st I had the honor to chat with Professor Zissis Samaras, mechanical engineer & professor at Aristotle University of Thessaloniki, Greece. He was recently the Keynote Speaker at the 5th annual PEMS Conference held by UC Riverside CE-CERT in Riverside California.

Dave: Thanks for taking time out of your schedule to discuss the industry, Zissis – what can you tell us about your background?

Zissis: My main emphasis is on applied thermodynamics which means internal combustion engines and their emission controls.

Dave: Zissis, specifically what is your background in fuels and emissions? How did you end up doing what you are doing?

Zissis: Actually, my own personal interest started with my PhD completion in the early 1980’s. But I have to acknowledge that the original focus at our University came from my old professor and teacher, Constantinos Patas, who was the professor before me at this (Aristotle University) laboratory.
Constantinos came from Daimler Benz Stuttgart. He was very much focusing on emissions controls, which were just beginning to gain attention.

He came from Daimler with a diesel particulate filter.  This filter was actually a first-of-its-kind sample from Corning; we said, ok, let’s try to study it.  And then, we expanded to all kinds of emissions controls since we were immediately approached by the Greek government and they were asking for some support towards the degrading Athens air quality at that time.

So this is how the whole thing started here. But, we have been focusing as a group, myself in particular, on technology development. To this end, we have had a number of collaborations with multiple motor vehicle industries around the world, as well as the European Commission which has been funding us also for support for regulations development.

Dave: You mentioned the European Commission. I saw that in your presentation you had an acknowledgement to Pierre Bonnel – so you have been involved with Pierre for quite some time?

Zissis: That is right – we have worked with him on many different projects.
To give you an idea of just a few…

We have been developing COPERT  –  it is the emission factor software of the European Union, similar to what EMFAC or MOVES is in the United States.  We are constantly improving it to support European Union policy towards improvement of air quality.

But – we constantly require more accurate & more representative emission factors.

So – we have been involved in real world emission factor activities very early on, either using different test cycles or regulatory cycles or making onboard measurements not necessarily  with official PEMS systems as they have been developed until now.  For on board measurements we have been extensively using sensors: such as NOx and soot sensors, while we are also considering simple CO or hydrocarbon measurement techniques in small units.

And we were always calibrating them against laboratory measurement in order to be sure of the quality of the data.  So, this activity of real world performance vehicles was our main target from the beginning.

Dave: So, you were more interested in the real world data and less focused on the USEPA 1065 standard?

Zissis: That is absolutely correct. Yes.

Regulation is one thing, but what real world tells me is the most important thing. Now, regulation needs to be as close as possible to real world.

Dave: Interestingly, Dr. Chris Frey of North Carolina State University has contributed a great deal of his real world data to the USEPA MOVES Model. And Chris’ data were based on non-1065 equipment.

Zissis: That doesn’t matter to real world evaluation.

Dave: So what do you think is the most pressing challenge that the transportation industry faces today?

Zissis: I think that energy efficiency is probably the most important issue that the industry faces. That’s the main problem of the future.

As regards air pollutant emissions we largely know today what the solutions are.  We have catalytic converters – very effective in reducing emissions from spark emissions engines.  We have diesel particulate filters, also very effective.  We can virtually get to zero emissions.

But what we have to make sure is that what is shown on the regulatory cycle laboratory emissions is really replicated in the real world!

However, I think the most significant challenge of this booming transportation market is – what to do with CO2 emissions and how to best improve the performance of the transportation sector.

Currently, the transportation sector is really the major “strength”. We can move around – mobility – it’s home, right? It’s transportation of goods – it is absolutely necessary.  But we have to make it more energy efficient; I think that is the main thing – the main focus.

Dave: You mentioned CO2 – what are your thoughts on NOX and PM?

Zissis: I think this is the remaining issue to be sold under real world conditions.
As I said before, I think the main target is to make sure that what can be demonstrated in particular laboratory conditions is replicated on the road – this basically applies to PM and NOX.
PEMS and on-road measurements are necessary to constantly demonstrate compliance, but also to pick up those vehicles that are high polluters.

Dave: Where do you see the transportation industry heading in next 1, 3, 5, and 10 years?

Zissis: I see continued growth. Growth everywhere. I think that much of the growth is going to come from the East actually – China, Indonesia and those countries.  China is the biggest market in the world and it is going to be even bigger. It is probably going to be – in a few years from now – bigger than both Europe and the United States combined.

So, it’s growth. It’s a big number. Massive expansion. More than we imagined in the 90s.
Therefore, efficiency and cleanliness – it’s really a must now.  Because I think we have something like a billion-plus vehicles on the planet right now. But this is expected to double.

So – our vehicles have to prove that they can be energy efficient and also material-wise they have to be environmentally friendly. I am sure that you know the discussion about lithium. If we are going to go to lithium batteries where the lithium is going to come from…?

Dave: Yes, it is coming from Africa and it is difficult to obtain.

Zissis: Exactly! And then you factor in China’s expansion; so – these things need to be taken into account. It is a big world – massive numbers now.

Dave: Seeing as you touched on electrification – what are you most excited about regarding latest trends?

Zissis: I think that a real challenge are hybrids operating on alternative fuels. Being equipped with highly efficient internal combustive engines. Which means variable compression, cylinder deactivation, extreme downsizing, etc. – everything that we have encompassed over the last several years – over the last century – it needs to be realized very fast now.

And since we do have the means – mechanics, materials, computers, simulation – there is no reason not to go to very sophisticated machines.  They have to be affordable – easy to manufacture.  But I think we also have the issue of scale. We are talking about millions, tens of millions of vehicles being produced every year. These solutions should be, can be, affordable now.

Dave: Which countries do you think are most pro-active and/or progressive?

Zissis: Europe has recently been in the forefront of CO2 reduction. It is the first to introduce new targets. It continues to be persistent of those targets. Of course the United States is the first with capping standards. Parts of the United States, California for example, is always leading in some areas.  The US was the leader with air quality – criteria pollutant reduction – everything started in the United States.  And all the rest of the world followed; Europe included.

Europe is leading in the area of energy efficiency. It’s trying to invest more than the United States here.

If this is reality then probably the East, like China and Japan, should take the lead in more systems approach.  The world needs to somehow try new technologies – highly efficient – running on alternative fuels and electrical machines.

Dave: Which countries/nations have the greatest challenges to overcome?

Zissis: I think this goes to the technology-developed world. I come regularly to the United States; but driving on the highways of LA, I always get the feeling – as I do sometimes on highways in the Netherlands, that we are at saturation. Millions of vehicles idling around!

I think this model has reached its limits and we have already the need to make different decisions.

Private transportation is beautiful; it’s independent. But, at times it is a tragedy!  It took me 3 ½ hours for a trip that would normally be close to 1 hour in California.  It happens everywhere.

I believe that all the technologically-developed world is faced with the same problem – saturation on the roads, saturation in the number of cars, and of course I think we are aware we are abusing our energy resources. We have been blessed with fuel by nature, or God, or whoever it is. And we are not using it wisely at all.  So we have to act fast.  Probably against today’s way of thinking.

If the same approach is taken by China and India then I think we are at an impasse.
I do not see a particular difference between developed and undeveloped countries. We are all faced with the same thing. But there are some who are much more saturated and more close to the problem than others.

Dave: With these types of issues at hand how do we approach that kind of a problem?

Zissis: If we take it from a generalized point of view, we will have some nations that are technologically-developed and can afford to use the technology they have developed themselves.

However, this technology should be easily incorporated or adopted by less technologically developed nations who are lacking the money.

What they are buying or using is really what normally would be scrapped in our societies. The question is what do we do? I don’t think we are going to ever solve those problems.  I think it is our responsibility to make cars more durable, better, more affordable, less prone to decay. I was thinking about all the new technology we are introducing. You are entering a car and you can talk to the car. Everything is so automatic.

Dave: You just made me chuckle; back in the mid-1980s they came out with cars that talked to you with pre-recorded messages.  I remember thinking that it was a pretty stupid idea, but it was fascinating. I also remember thinking “how far are we taking this?” “A car that can drive itself and park itself?” Next thing you know, Mercedes develops such technology, and now it is available in a Ford product!

Zissis: But that is also the point!  It is mass production of those systems that make them so affordable. Right? So easy to buy. So easy to install. Probably if it stayed with Mercedes, it would always be expensive because it only a small number of cars would be purchased. But now we are talking about millions every year.

And this also reminds me of something that I should have said already. I think ITS – Intelligent Transportation Systems – are really the next logical step. This can also improve safety, comfort, but also efficiency.  Take advantage of more intelligent approach to transportation as a whole.

Dave: A couple other questions that would be interesting to the folks that read this blog. The first question is what industry publications do you follow?

Zissis: I regularly try to follow SAE papers. This is a standard for our industry; for us is a must. And it became more international – SAE is everywhere. The classical – international conferences are very important to publish. There are also some European publications which are all equally important: MTZ  ( and ATZ ( – these are two German publications which are also important ones to see what the latest trends in the automotive industry are…

Dave: One last question – what is your most interesting project that you are part of that you can tell us about?

zissis_samarasZissis: Actually, there are two projects that I am currently involved in of interest.

One is the further development of a soot sensor that could be integrated into OBD systems – as a first step – but then, as a second step – could be used as an onboard sensor for online monitoring of particle emissions. A real time particle sensor.

So that is something that I have been working on for the past 10 years or so and now it seems as if it is closer to mass production since OBD standards are much more stringent and therefore the use of the sensor will be strict and this means that it will be improved.

The other project is kind of related to the first one. It is funded by the European Union program on research  and it is called ICT-Emissions.  It calculates the CO2 benefit you can get from ITS – how existing information coming from the cars and from infrastructure can be used to see if implementation of specific measures focusing on the infrastructure, or the cars themselves, or in combination can help improve energy efficiency and pollutant emissions.

Dave: Thanks for taking time for the interview, Zissis. Anything else you can add?

Zissus: Yes – I will make any of the information we discussed available; let me know what questions arise.

…and that’s it for this time.

We has several interviews coming up, so check back often!

Dave Miller