Automotive Industry Faces: Bret Zimmerman, Senior Engineer - SCR & OBD - Ford Motor Co.

"Really, we’ve gotten to the point now with the hardware that we’ve gone
from the invention phase of SCR. We now at least know how to do SCR and
therefore, it’s taking it more into the commodity phase…"

Automotive IQ spoke with Bret Zimmerman, Senior Engineer – SCR and OBD, Ford Motor Company, USA at our 5th International Conference on Selective Catalytic Reduction. Mr. Zimmerman discussed future challenges for diesel SCR and shared his experience into how fuel efficiency correlates with engine-out NOx.

Full Interview PDF

Automotive IQ: I’m here with Brett Zimmerman of Ford. Could you share a bit of information about your background and how you came to work for Ford?

Brett Zimmerman: I joined Ford Motor Company in 1999 after working at Roush Industries as a contract engineer to Ford. So starting in the early nineties, I worked at Ford’s advanced emission department on gasoline. I held a number of different engineering positions and gasoline emission programs. Most notably, the Aston Martin DB9. So I do get to work on a few fun things…Then I decided to take my turn at diesel and go over to the Super Duty group.


Automotive IQ: Within diesel, regarding SCR, what do you see as the most challenging aspects coming in the next couple of years and then looking several years beyond?

B.Z.: Really, we’ve gotten to the point now with the hardware that we’ve gone from the invention phase of SCR. We now at least know how to do SCR and therefore, it’s taking it more into the commodity phase where, like the other components, fuel injectors, spark plugs, oxygen sensors, they are parts that you can go buy from people and you can implement them and the whole cost of the system really needs to come down now. I think as more and more suppliers come in to the market for the tanks, the pumps, the injectors, the catalysts, the washcoats, things are definitely coming down in price and as the price comes down that allows us to put it on smaller and more inexpensive vehicles.


Automotive IQ: So the packaging becomes easier?

B.Z.: The packaging actually becomes harder. Well, packaging never seems to be easy. People are always amazed. The longer you work on semis and super-duties, such as I do, you realize that packaging is just as much of a constraint as it is on a Focus or Fiesta. There’s never any space for something that’s not a customer want. You really have to struggle to get a good package for the SCR system to function properly.


Automotive IQ: You mentioned that as fuel efficiency standards become more stringent and we’re always trying to eke out more and more miles per gallon, that that would actually pose an additional challenge. Could you go into that a little bit?

B.Z.: As CO2 requirements go down, you are trying to drive fuel economy better and better, typically that trade-off raises engine out-NOx. There are not very many technologies where you can make the engine run poorer and get better CO2 emissions, so you have a fuel economy versus emissions out curve that you have to sit on. Where you really pick to sit on that curve depends on how efficient your SCR system is. If you have a very efficient SCR system, you can find that you can raise your engine out NOx quite a bit and that’s what we’ve done with our Super Duty truck. If you take the 2008 as a baseline, Dodge came out with an LNT version for their 2010 truck. They lost, I think, five to six percent fuel economy from LNT. First by raising the feed gas from our 2008 we’ve actually allowed much better fuel economy upwards of, in some cases, six or seven percent. So the delta from LNT to SCR is about at 10 or 11 percent which is really a big change to the customer.


Automotive IQ: Absolutely, it’s an extra fold in the wallet for sure.

B.Z.: Yes.


Automotive IQ: I’ve heard rumors about solid ammonia SCR. Do you have an opinion on that technology that you can share with us?

B.Z.: No, I think it’s a very interesting technology. It definitely solves many of the problems that we do have with SCR: tank volume, freezing, thawing, and carrying around all kinds of water that isn’t really part of anything that we’re doing. The problems really lie in that we’ve set up an entire infrastructure around our current system and this has definitely not been easy to get that done. Additionally, if you come out to customers every few years and say, "Okay, that really didn’t work great, or we want you to do this now." There are issues with that so it’s tough from an infrastructure standpoint along with a customer training standpoint. The customer is only going to accept so many new technologies so fast.


Automotive IQ: I appreciate that. It was very helpful and very interesting, I appreciate your time.

B.Z.: No problem.