# Strategies for Reducing Automobile Fuel Consumption
## 3 Vehicle Design and Technology
### Improved Fuel Economy of Vehicles by Reducing Friction Losses
The general objective is to engineer lubricants that extend the components' longevity, while concurrently optimizing engine performance. During _cold starts_ and brief journeys of an ICE, engine oil may not achieve sufficient operating temperatures, hindering the lubrication of systems and subsystems. Persistent low oil temperatures can generate problems such as the accumulation of fuel, combustion residuals, and water. Concurrently, the sedimentation of engine oil additives at the sumb base, due to moisture contamination, can potentially neutralize the oil's corrosion inhibitors, thereby risking the engine's integrity against corrosive elements. Specifically in gasoline-fueled vehicles, fuel filtration into the oil can substantially reduce its viscosity, diverging from anticipated values at given temperatures. In such driving conditions, the oil's natural thickening at decreased temperatures is somewhat counterbalanced by reduced viscosity from fuel incorporation during a cold start of the engine [47]. During this period, it is crucial to focus on increasing the rate of heating of the cylinder liner. This helps to improve combustion, resulting in reduced emissions. Moreover, a faster warming of the cylinder liner reduces friction levels against the piston ring, leading to improved fuel efficiency. In addition to this, it is advisable to enhance the rate of lubricant heating to minimize losses. In _nanotribological research_, several pressing requirements have been delineated. These include (a) the design of nanostructured materials with higher strength and hardness and with self-repairing capabilities and safety features; (b) the incorporation of carbon and ceramic structural materials, with strength values superior to that of steel (by as much as ten times); (c) the evolution of polymer components that not only possess three times the strength of currently used materials but also have melting temperatures surpassing 100 \({}^{\circ}\)C; (d) the quest for multifunctional materials for mitigating friction, wear, and corrosion; (e) the exploration of nanoparticles' incorporation to reinforce aluminum alloys against wear; (f) the application of _nanocoatings_ on metallic substrates to achieve higher hardness values and reduce friction; (g) the innovative utilization of nanoparticle-reinforced materials, as potential replacements for metallic elements in vehicular contexts; and (h) the development of predictive models and simulations leveraging multi-scale computations to produce materials (bulk and surface) with superior tribological attributes. Such advancements are aligned with a future where materials exhibit enhanced performance and longevity, especially in industries such as automotive engineering, harmonizing with sustainability objectives. While tribology plays a significant role in increasing the efficiency of road vehicles (and other industries), it has, until recently, remained somewhat sidelined in climate change discourses [43]. According to the BP Energy Outlook 2019 [1], the total primary energy supply (TPES) required was quantified at 584 exajoules (EJ). Leveraging proficient tribological strategies could have caused a medium- to long-term CO\({}_{2}\) emission reduction of 6% to 11% in 2019, translating to global savings of 35-64 EJ. Importantly, forecasts predict an increase in TPES to 961 EJ by 2050 [48; 49; 50]. Given such increasing energy demands, refining tribological technologies and strategies becomes crucial.