Engineers will be so successful at improving the internal-combustion (IC) engine that global oil use will decline even as the number of vehicles in the global car fleet increases by 80% from 2010 to 2035. That is one of the surprises in a new Ricardo study, the key findings of which were announced Nov. 7. "Demand for oil may well peak before 2020 and then fall back to levels significantly below 2010 demand by 2035," the report says. In this way the study challenges the idea that "peak oil" will be a supply-side phenomenon (peak oil is the point in time when the maximum rate of global petroleum extraction is reached; opinions differ as to when that point in time is). The study notes that improvements to the IC engine will have a bigger impact on oil demand than vehicle-electrification technologies and that government policy is having a greater impact than is generally acknowledged in terms of those improvements. Biofuels and natural gas also figure into the equation. The study foresees oil demand peaking at 4% above 2010 levels. By 2035, demand is expected to be 3% less than 2010 levels, and with greater use of biofuels the decline could be greater than 10%. Also by 2035, transportation's share of global energy demand could fall below 25%, compared to 33% today.