WattSave compares EV and gas energy costs in real time — while you drive. Not estimates based on averages. Your actual route, your actual speed, your actual terrain.
Get it on Google PlayA quick look at what WattSave does while you're on the road
Everyone says EVs are cheaper.
But by how much? On your actual routes?
The generic "EVs save you X per year" stat doesn't account for how you actually drive. A hilly commute, heavy traffic, highway speeds — these all shift the numbers significantly. WattSave does the calculation in real time, using your actual movement data, so you get an honest comparison instead of a marketing average.
Four things that actually move the needle on EV vs gas comparisons
Side-by-side EV and gas cost updates as you drive. Not post-trip estimates — live numbers based on your current speed and acceleration.
Elevation changes, stop-and-go patterns, and speed variation all factor in. The app adjusts continuously so the numbers reflect your real driving conditions.
Configure parameters for different EVs and gas vehicles. Useful if you're comparing a specific EV you're considering against your current car.
Enter your local electricity and fuel prices so the dollar figures are accurate for where you live — not some national average that doesn't apply to you.
Three types of drivers who get real value from this data
You've seen the EV ads. Now you want actual numbers for your own commute, your own driving style, your own electricity rate. WattSave gives you that data without requiring you to buy an EV first.
If you drive a predictable route regularly, you can build up a clear picture of what an EV would actually cost you — not across a national average fleet, but on your specific path to work and back.
Running real trip data on your actual routes is a much stronger argument for (or against) fleet electrification than any vendor estimate. WattSave gives you the numbers to have that conversation grounded in reality.
Straight answers about how the app works
WattSave uses your device's GPS and accelerometer to track speed, acceleration, and elevation changes in real time. It applies physics-based energy models — accounting for rolling resistance, aerodynamic drag, and regenerative braking — against the vehicle parameters you configure, then multiplies by your local electricity price.
The result is an estimate grounded in how energy actually moves in an EV, not a simple average consumption figure.
Yes — that's actually the main use case. You drive your current gas car with WattSave running, and it simultaneously calculates what the same trip would have cost in an EV. You see the real-time comparison without needing to own or borrow an electric vehicle.
WattSave uses configurable vehicle profiles rather than a fixed database. You set the key parameters (battery capacity, efficiency rating, engine specs) for the vehicles you want to compare. This means it works for virtually any EV or gas vehicle — you're not limited to a predefined list.
Yes. WattSave is free to download and use on Android. No subscription, no paywalled core features.
Free on Android. No account required. Just open the app, start driving, and watch the numbers.
Get it on Google Play