400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760 Web: www.sae.orgSAE TECHNICAL PAPER SERIES 2004-01-0649 The New "7G-TRONIC" of Mercedes-Benz: Innovative Transmission Technology for Better Driving Performance, Comfort and Fuel Economy Juergen Greiner, Christoph Doerr, Harald Nauerz and Michael Graeve DaimlerChrysler Corporation Reprinted From: Transmission & Driveline Symposium 2004 (SP-1817) 2004 SAE World Congress Detroit, Michigan March 8-11, 2004Downloaded from SAE International by Univ of California Berkeley, Friday, July 27, 2018All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise,without the prior written permission of SAE. For permission and licensing requests contact: SAE Permissions 400 Commonwealth DriveWarrendale, PA 15096-0001-USAEmail: permissions@sae.orgFax: 724-772-4891Tel: 724-772-4028 For multiple print copies contact: SAE Customer ServiceTel: 877-606-7323 (inside USA and Canada)Tel: 724-776-4970 (outside USA)Fax: 724-776-1615Email: Customer Service@sae.org ISBN 0-7680-1319-4Copyright © 2004 SAE International Positions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE. The author is solely responsible for the content of the paper. A process is available by which discussions will be printed with the pap er if it is publishe d in SAE Transactions. Persons wishing to submit papers to be considered for presentation or publication by SAE should send themanuscript or a 300 word abstract of a proposed manuscript to: Secretary, Engineering Meetings Board, SAE. Printed in USADownloaded from SAE International by Univ of California Berkeley, Friday, July 27, 20182004-01-0649 The New "7G-TRONIC" of Mercedes-Benz: Innovative Transmission Technology for Better Driving Performance, Comfort and Fuel Economy Juergen Greiner, Christoph Doerr, Harald Nauerz and Michael Graeve DaimlerChrysler Corporation Copyright © 2004 SAE International ABSTRACT In September 2003, the Mercedes Car Group set another milestone by introducing the fifth generation of automatic transmissions developed and manufactured in-house since 1960. The world's first 7-speed automatic transmission 7G-TRONIC is featured in the Mercedes-Benz S, SL, CL and E-Classes with V8 gasoline engines. Deduced from the demands of the requirement specifications, the 5-speed automatic transmission was decisively improved; the result is a clear increase in spontaneity, agility, fuel economy, and driving comfort for the customer. And because of the harmony between the vehicle and its powertrain, excellent results in the areas of performance, reduced emissions, comfort, and acoustics are obtained. 1. INTRODUCTION The increasing demands on the powertrain are generated by the desire for differentiation from the competition in terms of comfort, performance, spontaneity, respectively agility, the agreements made by the ACEA to reduce Corporate Average Fuel Economy (CAFE) and governmental regulations. The impact of their demands on the automatic transmission's hardware features results in • Large overall gear ratio spread • Small gear ratio steps • A high degree of powertrain efficiency and • Directly controlled shifting elements. Of course, these features also meet technical goals regarding installation space, weight, quality, and manufacturing costs. The following essential guidelines were laid out by the requirement specifications:1. Lower fuel consumption • NEDC up to approx. 0.2 l per 100 km, during normal driving up to 0.4 l per 100 km 2. Increased comfort • Optimized shifting by direct control • Reduced noise level due to lower engine speed 3. Increased driving fun • Faster response time (by 0.1 s) • Faster downshifting (by 0.1 - 0.2 s) • Direct, multi-step downshifting and more acceleration power • Faster KD