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A 'wide' tyre spreads the weight across (perpendicular to) the direction of travel.
A 'narrow' type, still has some width, but tends to spread the weight more fore/aft (in the direction of) the direction of travel.
There's a 'cross-over' point where the AREA (width×length) of the tyre's 'contact patch' with the road surface reaches a minimum value: That's good for LRR but bad for braking.
Overall, a physically wide tyre presents a larger AREA of resistance than does a narrow tyre; so aerodynamically, a narrow type is better than a wide tyre of equal diameter.
Considering BOTH aero- and pavement (frictional) losses, the narrower tyre presents a smaller aerodynamic and frictional loss than does an overly wide (ala' drag racing slicks) tyre; but, without moving upward to a larger diameter wheel to regain equality in the total fore/aft contact area, the risk of reduced braking ability becomes a problem.
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