Investigating the Effect of Gearbobx Preconditioning on Vehicle Efficiency

This document explores the effect of automatic transmission fluid (ATF) preconditioning on vehicle fuel efficiency through detailed multi-domain vehicle and powertrain simulations developed in Dymola using Modelica.

The study uses a high-fidelity rear-wheel-drive passenger vehicle model with a six-speed automatic transmission, dynamic torque converter, thermal gearbox model, and predictive lubricant behaviour to analyse energy losses across different drive cycles and oil temperatures. By simulating standard NEDC and ARTEMIS drive cycles under varying ATF preheating conditions, the research demonstrates how reducing lubricant viscosity through gearbox preconditioning can improve drivetrain efficiency, reduce fuel consumption, and enhance vehicle performance, particularly in urban driving conditions and cold-start scenarios.