Dodge / Ram
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Ram man Dave Sowers took us on a walkthrough of the Ram 1500 pickup when it debuted at the New York Auto Show, providing us with more “depth” on why Ram made the changes it did, along with the “hows” of implementation.
Dave Sowers: We’ve always designed trucks for that ultimate level of capability. We’ve got to be able to haul our highest-rated gross combined weight rating up the steepest hill in the hottest temperatures. Our grille opening is designed to handle that and provide enough cooling under those circumstances.
What we’ve done (not only with the act grill shutters but a few other technologies) is to provide that high level of capability, but be able to shut part of it off some of the time to make it more efficient in the 90% of the time when you’re not towing under conditions like that.
So the act of grill shutters, when they close here, we’re going to operate them either fully open or fully closed. We’ll fully close them and that builds up air in here and the air will actually flow around the vehicle.
Allpar: Okay, so the air comes in through the grill. These are closed. This is blocked. Where does the air go?
Dave: So some air will go here [points to an opening below the shutters]. The majority of the air will be forced around the vehicle and flow across what is the most aerodynamic truck in the industry. As soon as the shutters close, it creates air pressure inside, and the rest of the air flows around.
It also happens in the bed of the truck. Some people that put the tailgate down to try to improve fuel economy and it actually doesn’t work. With the tailgate up, air pressure is created inside the bed, so more air flows over the vehicle with the tailgate up. We actually have better aerodynamics with the tailgate up. The best possible scenario is a tonneau cover, but it’s the same theory, where once the air is in there the rest of the air is going over the top. That’s what happens here.
I mentioned being able to have the most capability. Our fuel pumps historically have been created so that I can haul a long grade with wide-open throttle and provide enough fuel pressure and volume to maintain my speed the whole way up.
Allpar: Weren’t you controlling the fuel pump in the past? When you started doing the returnless fuel injection.
Dave: Yes. We had two fuel lines to the engine compartment: one with pressure, and one where we return pressure. We moved that fuel pressure regulator from the fuel rail to the fuel pump itself. But the fuel pump always still came on and ran at full speed and we just relieved the extra pressure right back into the tank. So that was returnless fuel injection.
Now what we’re doing is on-demand. We use pulse width management to do that, where we will only turn the pump on when we need it to generate the power. We get two benefits of that: lower electrical load and longer fuel pump life, because we’re not running it all the time. What we did in the past was the equivalent of turning your stereo onto 10 and covering your ears when it’s too loud. Now what we do is turn the volume down. [New Yorker analogy: turning the boiler up in the winter, and opening the windows to cool down.]
Allpar: I like that analogy. I might steal it for explaining alternators.
Dave: We also use pulse width for alternators. That’s been true for a long time; that’s not a new technology. But we’re using it for our cooling fans as well, so we don’t have to run them at full speed, we can run them at partial speed.
Allpar: Yeah. Although you’ve been doing that, you’ve had two-speed fans for a while haven’t you?
Dave: Yes, but we’d turn them on and turn them off. Now we can vary the speed with pulse width.
Allpar: In the press materials, it talks about oil and transmission fluid being cooled. In another spot it just talks about how the transmission fluid goes into a heat exchanger with the antifreeze. Does the oil have a similar heat exchanger?
Dave: It does. We get benefit from bringing both of them up to operating temperature faster. The primary benefit comes in the transmission. In colder climates, [including Pennsylvania], you could drive a vehicle for hours in the winter and the transmission might never reach that 190° F that we’re looking for for most efficient operation. So what we do is use some of that hot engine coolant through the heat exchanger to bring it up to 190° as quickly as possible, and that gives us efficient operation very quickly.
Allpar: That’s very clever. Is it as important as it used to be now that you’re using pretty much a synthetic transmission fluid?
Dave: Certainly that efficiency could’ve improved over time, but this is a big leap forward in efficiency given most customers’ drive cycles and like I said, the fact that they might never get to that level of efficiency. We even use it with engine oil. You might think that once you start running the engine, the engine, the coolant and the oil are all the same temperature but that’s not true. We’re circulating coolant around where the combustion process happens to take all the heat out that we need to. What we’re going to do is heat the engine oil up to that – about 190 degrees – as quickly as possible too. More benefit comes from the transmission than from the engine, but it helps in both cases.
Allpar: Why do you say that more benefit comes from the transmission?
Dave: Because the engine oil would’ve heated up eventually anyway. So we’re speeding up in the engine. In the transmission case we’re getting to where we might not have ever got to, in cold temperatures and low loads.
Allpar: Who gets credit for dredging the TorqueFlite name out and reapplying it?
Dave: You know, I was part of the process but I can’t point back to a single person. It was kind of a general agreement when it came up. We looked back at TorqueFlite… the TorqueFlite name was from a time when Chrysler was known for having bulletproof, efficient transmissions. That’s a notion that we all still held. So when the name came up in discussion, we all agreed. It sounded good. We did some research. We did some online research, and we did some customer research, and it does resonate that way. It speaks to high-quality transmissions and efficiency. When TorqueFlite 8 was originally used, the number afterwards referred to the number of cylinders in the engine it was mated to. Now we’re using it to designate the number of speeds in the transmission.
Allpar: Is that going to be an option with the HEMI after full production? Or is that going to be… in 2014, if I’m looking at a Ram, will I still see a 65 RFE anywhere?
Allpar: Are you keeping a 4.7 through the year?
Dave: What I can tell you is we have a 4.7 at least for ’13. We will introduce the TorqueFlite 8 with the HEMI in midyear ’13. [Allpar note: Chrysler has scheduled the discontinuation of 4.7 liter engine production, but it will be available in 2013 models.]
Allpar: I have not seen much mention of the 4.7 in marketing, generally speaking. Do you have capacity constraints in building it, or is it just not seen as quite the selling point compared with HEMI or is it mostly a fleet thing?
Dave: A large portion of our sales today are HEMI. We think with the Pentastar we’ll sell some more V6s, and the 4.7s kind of the ‘tweener engine. It’s still an important part of the lineup. We can produce as many as we need. It’s not a production constraint. It’s more of demand I would say. People who are buying V8s, most people, particularly individual consumers are buying the HEMI. Great name, great feel, great power, and very good fuel economy.
Allpar: With the 8-speed, I would assume better economy than the 4.7.
Dave: Today, the ’12 model year, the 4.7 and 5.7 have similar EPA fuel ratings. 20 MPG highway in a 4x2 configuration. They vary a little bit in the city. With the 8-speed, the HEMI will be hands down better than the 4.7 in both power, acceleration, capability and fuel economy.
Allpar: And when will we see gas mileage figures on these?
Dave: Later this summer we’ll complete all the EPA test cycles and publish them.
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