Driving

How we built this number

Nothing above is a headline figure we were handed. It is derived, step by step, from a stated consumption assumption and a stated efficiency, both of which are published with their sources. If you disagree with an input, you can see exactly which one to argue with.

The arithmetic

1. 10535 miles/yr driven
2. / 25.6 mpg fleet average = 412 gallons/yr of gasoline
3. / 3.3 miles per kWh = 3192 kWh/yr of electricity

Fuel used today

412 gallons

Cost of that fuel

$2,279

Electricity instead

3,192 kWh

Cost on E-ELEC

$986

Annual difference

$1,293

The consumption assumption

Assumes one car driven 10,535 miles a year — the California average — replacing a vehicle that achieves the in-use fleet average of 25.6 mpg rather than a new-car sticker figure, and charged at home. No age is assumed for the car, because none is needed: 25.6 mpg is what the fleet on the road actually achieves across every vintage in it, which is a measured figure and a better answer than a vintage we would have had to guess. Public fast charging costs considerably more than home charging and is not modelled here.

The rates we priced it at

Both sides of this comparison are priced at published rates, effective 2026-06-01: a PG&E residential fuel rate on the old equipment, and PG&E's E-ELEC electricity rate on the new. The exact figures, what they include, where they came from and when they were last checked are all on the methodology page. Rates move, and when they do, every number on this site moves with them.

The time-of-use caveat

E-ELEC is a time-of-use rate, not a flat price. Assumes overnight home charging on off-peak hours. This is the single easiest load to shift — nearly every EV and home charger can be scheduled — but it does have to be scheduled, and charging during the 4-9pm peak costs substantially more.

This matters more than most people expect. The same appliance on the same rate plan can cost substantially more or less depending purely on the hour it runs, which is why we state the assumption rather than quietly averaging it away.

Why it costs less to run

A gasoline engine throws away most of the energy in a gallon of fuel as heat; an electric motor puts nearly all of it into moving the car. Charged at home overnight, the same journey costs a fraction of what it costs on gasoline. The saving here is larger than either home upgrade for most households, simply because driving is where most people burn the most fuel.

What it is like to live with

For a household with a driveway or garage, the meaningful change is that fuelling stops being an errand — the car charges overnight and starts every morning full. Without off-street parking that maths changes substantially, and public charging is expensive enough to erode much of the saving. That is a real limitation in San Francisco, and one we would rather tell you about up front.

What it changes beyond the bill

Tailpipe emissions are concentrated exactly where people live and walk, and are linked to respiratory and cardiovascular harm in the neighbourhoods they pass through. An EV moves that emission off the street entirely, and onto a grid that keeps getting cleaner.