No change there, one might argue. Navistar's approach to EPA 10 has consisted - so far - of a combination of sweeping statements and the instruction of learned friends in almost equal measure. Contained within the Today's Trucking report, however, are some seemingly concrete claims, which, in turn, provide a means of comparison between Navistar's current position and that now held by the other two OEM's most recently flirting with in-cylinder alone treatments - namely MAN and Scania.

Participating on the conference call were Jack Allen, President of Navistar's NA Truck Group, Jim Hebe, EVP NA Sales and Ramin Younessi, GVP of Product Development and Business Strategy. Obviously, Helmut Endres, previously a key player in NAV's 2010 strategy was not present, as he is no longer in the employ of Warrenville. Those who keep a close eye on such matters will remember that Karl-Viktor Schaller, previously MAN's tech boss left the German OEM just prior to its announcement of a technological volte-face a couple of months ago.

What did we learn? Younessi was in Colorado, where he is involved currently in a manufacturer's test program. Nothing strange here, but we could have expected - quite reasonably - to have obtained some insight into real world - namely trucks placed with actual truck operators - trials. Bearing in mind that we are less than five months away from the onset of the EPA 10 regulations, it would be reasonable to assume that NAV's testing program is now in its final stages; namely real trucks working for real truck operators. And some actual guidance as to how they might be performing under such conditions would be useful; MACK has, after all, been offering similar guidance for some months now.

Let's put that to one side, and consider the technology. It is, says Younessi, "a lot of little tweaks". Allen is similarly self-effacing: "What we're really doing is an evolutionary change, (he) said, "the derivative of an existing technology."

According to Today's Trucking, the changes are thus:

Changes include advancements in fuel injection, with the "next generation" fuel injection systems delivering fuel to the combustion chamber multiple times per cycle at higher pressures.

Air-intake management is improved with the use of dual turbochargers. And Younessi says the two-stage cooler should reduce the number of DPF regeneration events but couldn't quantify the extent of those reductions.

We're both underwhelmed and surprised by this. Both MAN and Scania have now said that Euro V (2.0 NOx) is as far as EGR can go, and, as European, and, particularly, UK readers will be only too well aware, both OEMs grabbed a very marked advantage through Euro IV and V with this process. For either to have given up, when all that was required were a number of little tweaks seems to us to be something of a rum do. And yet little tweaks have taken NAV to 0.5 NOx. Odd.

As too are the claims to fuel injection and turbochargers. Here. From the SOE, is detail of MAN's Euro V EGR engine - which will not get above 440 bhp. It speaks of dual turbo-charging. Whilst here is information about Scania's XPI injection system (a joint venture with Cummins) - which provides for the same phased high pressure fuel delivery that NAV appears to be speaking of, and at rates of up to 2400 bar. Has Navistar got beyond 2400 bar? If so, this can hardly be described as a little tweak, and not just in terms of technological advancement. In January last year, Automotive World carried a report citing Martin Bull, technical director at Corus Engineering Steels, who opined that 3300 bar injection pressures would be along for Euro VI (de facto EPA 10) but at an up to five-fold increase in cost. Are we to assume that NAV's 2010 engine will contain such technology? If we are, then the $8000 price hike becomes rather easier to understand. If not, then Eight Large seems like a lot of coin for a new combustion bowl.

We remain very suspicious of all of this. Quite how Navistar has taken a MAN engine and done to it that what MAN itself has said - some years ago (see below for an exert from MAN's pre IAA 2006 briefing) - was impossible is a neat trick. But that it has done so using - apparently - existing components, existing technology and but a few little tweaks seems utterly bizarre.

Navistar's apparent modesty during its conference call can only be described as peculiar - and, for that matter, a refreshing change of course - if everything is, indeed, on the level. Leaving aside the issue of EPA credits, it would appear to have achieved Euro VI (0.5 NOx) without much effort. This is quite a spectacular breakthrough for a company that has reverse engineered an existing product, draws on little by way of a track record in HD engine design and manufacture, and yet has, seemingly, achieved the impossible. There must be a number of people in both Munich and Södertälje who would love to know its secret.

MAN Pre IAA Press Briefing September 2006:

The underlying EGR technology is good for Euro 5 and beyond

Not only today but in future too customers will be able to put full trust in EGR. Several years ago MAN was the first European commercial-vehicle manufacturer to choose cooled exhaust-gas recirculation (EGR) as the cornerstone of its engine strategy. Even back then this solution enabled MAN to comply with the Euro 3 limits without incurring any increase in consumption, as many customers can confirm. A further development of EGR technology is therefore the basis for MAN solutions aimed at compliance with forthcoming exhaust-gas standards such as EEV (Enhanced Environmentally friendly Vehicle), Euro 5, Euro 6 or the US limits under the EPA 2007 and EPA 2010 regulations.

The new D20/D26 Common Rail engines have been specially developed for compliance with future emission limits. In cooperation with the US company Navistar International Corporation the D20/D26 CR is as planned being subjected to further development with a view to satisfying the strict US EPA 07 standards and the somewhat less strict Euro 5 standard on EGR basis without any additive. At the IAA Commercial Vehicles this so-called ITEC engine for the US market will be exhibited on the MAN stand. The advantages of EGR-based solutions are obvious: no additive, no dependence on an infrastructure that is just being created, no effect on space or weight in the vehicle, a maintenance-free concept and robust and economical engines.

MAN is excellently equipped even for the EPA 2010 standard, which has already been fixed by law, and the Euro 6 standard currently being planned, which is to be expected to come into force in 2012. Many experts in this field think that given the current state of the art no commercial-vehicle manufacturer will be able to reasonably comply with the Euro 6 limits without a system for reducing emissions inside the engine such as exhaust-gas recirculation. They will therefore be forced to develop systems and components like this too. With Euro 6, however, use of SCR technology alone without EGR will reach the limits inherent in the concept.