How to Read City and Highway Range on the 2025 Zero S/SR/SR-F/SR-S

The least intuitive line in the 2025 Zero S/SR/SR-F/SR-S North America owner's manual is not a performance claim, it is a definition. Range values labeled "Combined" are based on a calculation that assumes a duty cycle of 50% City / 50% Highway. That is the one figure in the table nobody actually rode: the City and Highway procedures are both run on a single charge to report a measured range, while Combined is arithmetic performed on the other two. Read the spec sheet again with that in mind and the ranking of the three numbers flips.

For a US buyer or a fleet planner working from that page, the practical split is simple: plan stop-and-go work around the City figure, gate any sustained highway leg on the Highway figure, and treat Combined as the answer to a question about a route that is exactly half and half, which almost nobody drives. What follows is mechanics rather than opinion: how each number is generated, how to weight the two measured ones by your own mile split, and where that weighting goes wrong.

Why the Combined Number Is the Weakest of the Three

A fixed split is a statement about a route, not a property of the motorcycle. Because the split is fixed, the figure answers exactly one question, what this bike would do on a trip that is half stop-and-go and half cruise, and a route with any other mix gets estimated with somebody else's proportions. The same manual notes that the same motorcycle often yields different ranges from one full recharge to the next, so there is no single true range to converge on; there is a spread, and each test standard carves a fixed point out of it.

Errors from using Combined do not average out, they lean. Imagine an 80/20 urban route: the even weighting drags in highway consumption the rider never incurs, so the figure understates the day; on a 20/80 freeway commute it overstates it, and overstating is the expensive direction because that is the one that strands a rider. There is a filter before any of this applies. Range values in the manual are measured using different standards according to the country the motorcycle is sold in, so a number copied off a non-US listing may not be the same test at all; confirm which standard produced the figure before comparing it to your route.

What the City Range Test Actually Recreates

The City test is specified to determine riding during stop-and-go operation typically found in urban areas, and that definition matters more than the number it produces. Speed, acceleration, number of starts and stops, ambient air temperature and changes in elevation are all named in the manual as factors that affect range, and the City procedure is the one that deliberately builds starts and stops in. Because the test is defined around repeated launches, the City figure prices in the acceleration events a downtown route actually contains instead of smoothing them away at a constant cruise.

Why a stop-and-go figure usually reads higher than a steady-speed figure on the same pack comes down to where the energy goes. At low average speed aerodynamic drag is small, so most of the draw goes into accelerating mass and into rolling resistance, and part of the kinetic energy from each launch is recovered during deceleration instead of being burned off entirely. A steady 70 mph cruise has almost no stops to recover from and pays a drag bill on every mile. Which means the City number is honest only if your urban legs carry roughly the stop density the test assumes; a wide arterial with synchronized lights sits closer to a highway leg than to the test's model of downtown.

Why the Highway Figure Moves More Than the Speed

The Highway procedure uses two separate constant speeds, 55 mph and 70 mph, to simulate highway riding, and both procedures are run on a single charge to report the measured values. Two fixed speeds rather than a ramp is the detail that decides how you use the number: nobody can scale it to 62 mph by interpolation and expect better than a guess.

Drag force on a motorcycle rises with the square of speed, the power needed to hold a speed rises with the cube, and the energy consumed per mile, which is the quantity range is actually made of, rises with the square. Because that relationship is quadratic, a small increase in cruise speed costs a disproportionate share of the pack, and the penalty grows faster than the speedometer does. A 45 mph suburban run should therefore beat the published Highway figure, since the figure is anchored at 55 and 70, while a long 75 mph interstate leg does worse than it. Treat the Highway number as a gate rather than a forecast: it tells you whether your cruise speed sits inside the tested envelope, and it turns optimistic the moment your real speed is above the upper test speed.

Start by Splitting Your Route Into Two Buckets

Write the route down leg by leg before touching a calculator. Mark each leg as stop-and-go urban or sustained highway cruise using the manual's own definitions of those two tests rather than gut feel about what feels like highway. A two-lane road with a light every mile is stop-and-go for this purpose even outside city limits, and a freeway crawl at 20 mph is not a highway cruise and should not be bucketed as one.

Total the miles in each bucket and convert them to shares of the trip. As a hypothetical, take a 30-mile commute where 18 miles are stop-and-go surface streets and 12 miles are sustained freeway; that is 60% City and 40% Highway. Those shares are an assumption about a route, not a measurement of a motorcycle, and the arithmetic is identical for a five-bike fleet route and for one commuter.

Then Weight the Figures and Check the Result

The weighting method is not invented here. Combined is exactly this arithmetic run with the fixed halves replaced by your shares, so keep them as fractions that sum to one, multiply the City figure by the city share and the Highway figure by the highway share, then add. On the hypothetical 60/40 route, three fifths of the City number plus two fifths of the Highway number is the blended estimate.

Treat that result as an upper bound whenever the route is highway-heavy, because the weighting assumes energy per mile stays constant inside each bucket. Speed and acceleration are continuous variables rather than two settings, so a leg averaging 75 mph sits above the top test speed and consumes more per mile than the Highway figure implies. On a route that is mostly 45 mph the same arithmetic runs the other way and the estimate is conservative, which is the harmless direction to be wrong in.

Where Your Weighted Number Will Still Be Wrong

Here's the catch: the blend is only as stable as the route it was built from. Of the range factors the manual names, every one except ambient air temperature moves with how the rider uses the bike. A blended number computed from your splits holds while you keep riding those splits; change your launch habits, add a passenger, or start taking the hillier way home and the same arithmetic now describes a route you no longer ride.

Cold ambient temperature and climbing both push consumption up without changing the mile split at all, which means the blended figure is a fair-weather number until you adjust it qualitatively; a winter commute on the same route should be planned against a lower figure than the summer one. And yes, you will feel that before any spreadsheet catches it, because the February commute is not the July commute even when the odometer says the miles are identical.

Confirm the Estimate on the First Weeks of Riding

The manual suggests riding conservatively when you first get the motorcycle, to get to know the bike and the commute, and that suggestion doubles as a calibration instruction. The more conservatively you ride, the better range you can expect, so a conservative opening week establishes a baseline that separates route effects from throttle effects; ride hard from day one and a shortfall tells you nothing about whether your splits were wrong.

Repeat the same route, note the range at each recharge, and compare that variation against the weighted prediction rather than against any single trip. If real consumption lands inside your comfortable margin across a week of the same route, the splits were right. If it lands outside on every repetition, the split was wrong, not the spec sheet, usually because a leg bucketed as stop-and-go is really a steady 50 mph run or a freeway leg is running well above 70.

Today's job is short: pull two weeks of your own route, total the miles in each of the two buckets, weight the City and Highway figures by those shares, then ride conservatively for the first week and compare what the bike consumes against the number you wrote down. A prediction you can check in seven days beats a spec-sheet figure you cannot check at all.