Thatโs a great observation, and it actually reflects what traffic engineers describe with terms like car-following theory, headway management, and the fundamental diagram of traffic flow. When cars follow too closely, small speed changes turn into waves of braking and accelerating that spread backward through traffic, a phenomenon called capacity drop. This doesnโt just hurt fuel economy but also makes congestion worse overall.
Put simply, leaving more space between you and the car ahead lets you drive more smoothly without constantly hitting the brakes or throttle. That saves fuel because your engine isnโt working overtime to keep adjusting. It also helps everyone else on the road by preventing the chain reaction of stop-and-go driving. Your anecdote about using adaptive cruise control on its widest setting is a perfect example of headway management working as intended. Itโs not just better for your MPG but for the whole flow of traffic.
Iโm not a traffic engineer, just a massive nerd who finds obscure topics like this one fascinating and research-worthy.