Understanding sedan-specific solar sizing
Why EVs sometimes flip the usual city/highway pattern
Gas vehicles are typically more efficient at highway speeds, where the engine runs closer to its optimal RPM range, but many EVs show the opposite pattern. Regenerative braking recovers a meaningful share of kinetic energy during city stop-and-go driving, while sustained highway speeds increase aerodynamic drag substantially with no equivalent recovery mechanism, which is why many efficient sedans post better kWh-per-100-mile figures, tracked on fueleconomy.gov, in the city than on the highway.
Why sedans show this effect more clearly than other vehicle classes
Sedans, especially the most aerodynamically optimized models, tend to show one of the largest gaps between city and highway efficiency of any EV class, since their low drag coefficient makes city-driving regenerative braking benefits especially pronounced relative to highway drag losses. Trucks and SUVs, with less optimized aerodynamics overall, sometimes show a smaller relative gap between the two driving conditions.
When blending matters versus when the combined rating is fine
If your driving is reasonably balanced between city and highway, similar to the EPA test cycle's own mix, the combined rating already accounts for that blend reasonably well. Blending the two figures yourself becomes more valuable specifically when your actual driving pattern is unusually skewed toward one condition or the other, like an all-highway long commute or an entirely urban stop-and-go routine. Once you have a panel count, the roof space vs output estimator checks whether your roof can actually fit it.
Estimating your city/highway split without guessing
A rough gut-feel estimate is fine to start, but your vehicle's trip computer or a phone mileage-tracking app can usually give a more precise split over a couple of representative weeks. If most of your daily driving is on surface streets with a short highway stretch to work, that might be closer to an 80/20 city-to-highway split rather than the 50/50 many drivers assume by default.
Taking this result further
Compare this result against the electric SUV calculator or electric truck calculator using the same mileage if you're weighing different vehicle classes, or move on to the EV charger sizing calculator to plan your electrical setup. If you charge at night, a battery matters more than panel count. The battery storage size calculator in our Battery & Storage section can help you size one for overnight charging.