UN R85 Supplement 10 (00 series) · UNECE Regulation No. 85 (ECE R85) — Uniform provisions concerning the approval of internal combustion engines or electric drive trains intended for the propulsion of motor vehicles of categories M and N with regard to the measurement of the net power and the maximum 30 minutes power of electric drive trains.
UN R85 — Supplement 10 to the 00 series of amendments
Supplement 9 → 10
- What changed
- Power at each speed may be measured at a set charge air cooler outlet temperature if the manufacturer requests and the type approval authority agrees.
- The set temperature is Toutlet, bench, N = Toutlet, vehicle, N - (Tamb – 298), with temperatures in K.
- Why
- The current method to measure the net power of charge-air-cooled engines is not suitable for high power charge air-cooled engines.
- While the test waits for the constant test condition, the charge air cooler outlet temperature rises, and the net power cannot be measured correctly.
- The alternative method is well recognized in SAE J1349.
Q1What changed6 changes
Alternative charge air cooler outlet temperature for the measurement of power (Annex 5, Table 1, footnote 9)
Under footnote 9, the manufacturer may now request an alternative for the measurement of power (at each speed). With the agreement of the type approval authority, the charge air cooler outlet temperature for this measurement may be set by a formula. The formula is Toutlet, bench, N = Toutlet, vehicle, N - (Tamb – 298). Toutlet, bench, N is the set temperature at engine speed N during the bench test. Toutlet, vehicle, N is the measured temperature at engine speed N during a test of the complete vehicle. Tamb is the ambient temperature during the complete vehicle test, and all three temperatures are in K.
Q2Why it changed
- Proposed by
- Expert from the International Organization of Motor Vehicle Manufacturers (OICA)
- Working party
- GRPE, 79th session (May 2019)
Reasons
The current method to measure the net power of charge-air-cooled engines is not suitable for high power charge air-cooled engines. While the test waits for the constant test condition, the charge air cooler outlet temperature rises, and the net power cannot be measured correctly.
Sources (2)
“The current test method for measuring charge-air-cooled engines net power is not suitable for high power charge air-cooled engines.”
“While waiting for the constant test condition (ref. Annex 5, 3.4.), the charge air cooler outlet temperature rises and the net power cannot be measured correctly.”
To solve this problem, OICA proposed an alternative test method. The method sets the bench charge air cooler outlet temperature to the temperature observed in the vehicle test, corrected to the reference temperature. This alternative method is well recognized in SAE J1349.
Sources (2)
“To solve this problem, OICA proposes an alternative test method to “set the charge air cooler outlet temperature during bench test to temperature which was observed by vehicle test and corrected to the reference temperature”
“This alternative method is well recognized in SAE J1349.”
Document trail
- 2019-03ProposalECE/TRANS/WP.29/GRPE/2019/11Proposal by the expert from OICA
- —RevisedGRPE-79-27-Rev.1New proposal that GRPE supported, as reproduced in Annex V of the session report
- —Working party adoptsECE/TRANS/WP.29/GRPE/79Session report, para. 34: GRPE requested the secretariat to submit Annex V to WP.29 and AC.1
- 2019-08Sent to WP.29ECE/TRANS/WP.29/2019/112Text that GRPE sent to WP.29 and AC.1
- 2019-11WP.29 adoptsECE/TRANS/WP.29/1149Adopted at the 179th session (session report, para. 116)
- 2020-05-29In forceC.N.217.2020.TREATIES-XI.B.16.85UN depositary notification
Q3Who is affected
Vehicle manufacturer
- If you want to use this alternative, request it and get the agreement of the type approval authority.
Component supplier
- No direct action for this role.
Technical service / Approval authority
- Be ready for manufacturer requests to measure power with the charge air cooler outlet temperature set by the new formula.
- When this alternative is used, check that Toutlet, vehicle, N and Tamb come from the complete vehicle test.
See every change side by side
RegVault customers compare every version of UN regulations, read the consolidated text and download the PDF.
ⓘ This report gives advice only. It is not legal or type-approval advice.