Brief review of open issues concerning electric vehicle testing for resolution during “Phase 1b” of the development of the light-duty vehicle emissions GTR (WLTP).

Review of main test procedures and flowchart towards determining pass/fails.

Plan for the Asian validation program to assess the repeatability of the WLTP test procedure as part of its phase 1b development.

Review of the European validation program to assess the repeatability of the test procedure described in the Phase 1a GTR text.

Heinz Stephen presentation on the technical report on the development of the harmonized driving cycle used in the global technical regulation on light-duty vehicle emissions (WLTP).

Heinz Stephen presentation on the technical report on the development of the test procedures used in the global technical regulation on light-duty vehicle emissions (WLTP).

Heinz Stephen proposals for addressing selected technical issues remaining to be resolved through the supplemental phase (“phase 1B”) for the refinement of the global technical regulation on light-duty vehicle emissions.

Progress report on test validation and refinement efforts from the Technical University of Graz (concerning the chassis dynamometer test) and TNO (concerning the road load/coast down test)

Proposal of a test to reflect the CO2 values obtained under “real life temperature conditions”.

Progress report of the WLTP “Additional Pollutants” expert subgroup.

Presentation on the use of “sailing” technologies to reduce CO₂ emissions and raising a question over the ability of the WLTP test cycle to account for the effect of sailing on vehicle emissions and fuel consumption performance. Sailing involves the decoupling of the engine from the drive shaft, enabling hybrid vehicles to cruise (or “sail”) on battery power alone until such time as the engine needs to be restarted to generate electricity and/or resume the torque functions.

Table of items for resolution in phase 1b in the development of the light vehicle emissions and fuel consumption global technical regulation.

Letter raising concerns regarding misinterpretation of the definition of a hybrid electric vehicle and resultant misapplication of approval requirements.

Proposal to refine the selection of reference speeds for the road load curve determination (Open Issues List Item 12: Coast down procedure (Annex 4)).

ACEA proposes to align the GTR text with the HEV definition used in the EC directive 692/2008/EC (Type-approval of motor vehicles with respect to emissions from light passenger and commercial vehicles (Euro 5 and Euro 6)).

Discussion of utility factors used in weighting emissions and fuel consumption. Utility factors are ratios based upon driver statistics and vehicle ranges recorded by off-vehicle charging (OVC) hybrid electric vehicles (HEV) (i.e., plug-in hybrid electric vehicles) in charge-depleting and charge-sustaining modes.

Proposal to maintain regulatory language to ensure that vehicles cannot be mis-fueled with a fuel (diesel, leaded or unleaded gasoline, etc.) other than that for which the vehicle is designed.

Heinz Stephen update on efforts to research and resolve open issues.

Supplemental Test for determination of CO2 emissions under representative regional conditions

Study on applicability of driving index (defined in SAE J2951) to WLTP test cycle.

WLTP drafting committee working document with corrections to the text of GTR No. 15.

Discussion paper on “open issue 13” (and 11) concerning corrections for wind conditions that impact coast down tests and times for road load determination and ultimately the road load settings of the chassis dynamometer. This document summarizes the views of the special ad hoc group formed to consider this issue.

Discussion paper on the use of the torque meter in the WLTP coast-down methods to measure the running resistance as part of the road load determination. This document summarizes the views of the special ad hoc group formed to consider this issue.

Proposal on a family definition for road load determination.

Definition of wind tunnel for road load determination (Open Issues #10 and #18).

Real-time tailpipe ammonia measurements from vehicles tested over the new Worldwide harmonized Light-duty vehicle Test Cycle (WLTC)

WLTP Phase 1b: Generic formula for hydrocarbon density

Initial material for deliberations on road load curve determination.

Progress reports from TUG (chassis dynamometer corrections) and TNO (coast down corrections) covering preliminary results (as of 27.03.2014).

Status report on the evaluation of road load determination (RLD) using a “wind tunnel plus chassis dynamometer” versus “coast-down” methodologies to enable a wind tunnel plus coast-down method in GTR 15 and on comparison of running resistance measured on a chassis dynamometer by ISO 10521-1 methods (stabilized speeds) and by deceleration (short method).

Status report prepared by Heinz Stephen.

Progress report on wind tunnel method, on-board anemometry and wind speed, speed points, torque meter method, default road load parameters, warm up procedure, and road load family concept.

Progress report on wind tunnel method, on-board anemometry and wind speed, torque meter method, default road load parameters, and road load family concept.

Proposal to add a generic formula for the density of total hydrocarbons to GTR No. 15 as part of phase 1b of its development.

Japanese proposals concern generic formulas for hydrocarbon density coefficients under WLTP.

ACEA background information to support a discussion on the flow and number of tests to be conducted under the WLTP procedures.

Electric vehicle lab procedures subgroup recommendations on vehicle emissions measurement in charge-depleting mode.

Proposal to dispense with this criteria in the WLTP test procedure.

Clean copy of the proposal for a “fundamentally amended” version of Annex 2 in GTR No. 15.

Proposal for a “fundamentally amended” version of Annex 2 including track changes and notes.

Initial working items for the phase 2 development of GTR No. 15 going into 2016.

Input for open issue items 10 and 18.

Proposal for modifications to the calculation parameter/coefficients r₀, a₁ and b₁ prepared by the WLTP downscaling issues task force.

Open issue 6 “Use of the gearbox, required data” concerns the following:

• modification of the definition of n_{min_drive} to make it more appropriate for modern engines and to make manipulations more difficult.
• Addition of n_max to section 2 and amendment of required data because the current definition is not appropriate for low powered vehicles.
• Replacement of P_normwot(n_{norm i, j}) in Section 2 (i) by P_wot(n _{i, j}) because there is no need for the normalisation.

Proposal to add requirements, address vehicles with a two-range transmission (low and high), and introduce the possibility to exclude crawler gears from the gear use calculation. The presentation proposed to add a provision: “For vehicles equipped with a two range transmission (low and high), only the range designed to normal on road operation is considered for the gear use determination.”

Proposals to clarify and focus the text on engine speeds and to address requests for an additional safety margin in the full load power curve at certain engine speed sections.

Proposals from the task force assigned to consider these open issues.

ACEA recommendation concerning the calculation of the CO2 value for an individual vehicle by the CO2 interpolation method (No addition of Matlab formulae in the GTR.)

Initial comments concerning the chassis dynamometer calibration, force transducer and dynamometer parasitic loss calibrations, measurement equipment, and force measurement system under GTR No. 15.

Final proposal of the Speed Points (OIL #12, #21) drafting group.

TNO draft report on “Correction algorithms for WLTP chassis dynamometer and coast-down testing”.

Open issue #28: proposal of text for adoption by the WLTP informal group.