Adjustment of truck data summary

NTM has added Euro 6 (VI) truck data in NTMCalc. In this amendment NTM also made a general update to the new HBEFA 3.2 ( http://www.hbefa.net/Tools/EN/MainSite.asp ) from the previous HBEFA 3.1. There has also been a minor general change in fuel consumption estimates. The updates are described in more detail below.

Update on Euro 5 (V) trucks (including both EGR- and SCR-equipped trucks)
Euro 5 emission factors in NTMCalc 3.0 were previously taken from HBEFA 3.1. These emission factors were based on measured emissions of a few SCR-equipped Euro 5 trucks. Regarding EGR equipped trucks there were no emission tests available and hence these emission factors were based on prognosis and not on emission measurements.

Amendment

In HBEFA version 3.2 also the emission factors for EGR equipped trucks are based on emission measurements. Further there have been some more measurements on SCR equipped trucks and also some improvements in the modelling of emission factors for these trucks.

The emission factors of NOx, PM, CO, HC and CH4 have been changed in NTMCalc 3.0 due to the update from HBEFA 3.1 to HBEFA 3.2. The relative change may for some few specific configurations of road type and gradient differ as much as +200% or more (for CO, HC, CH4 and PM). But since the emission factors are low in absolute terms the changes does not lead to any major differences in emission factor levels. Thus the changes are considered as insignificant. Regarding NOx the difference after the update is greater for Euro 5 – EGR than Euro 5 – SCR because the forecast of NOx from SCR equipped vehicles showed up to be better than those of EGR equipped vehicles.

Our judgement is that the new emission factors reflect emissions in real traffic better since they are based on more emission measurements than the previous emission factors. More details about the updated emission factors in HBEFA 3.2 can be read in this report.

Updates on Euro 1 (I) to Euro 5 (V) trucks
In addition to the updates mentioned above, there have been minor updates of fuel consumption (i.e. energy use) for all vehicles. This impacts fuel consumption as well as CO2 and SO2 emissions. The impact is considered to be ±1%, i.e. neglectable.