Here is The Pelican, a practical solar powered and also digital tire pressure gauge you can carry along and use with no restrictions and no headaches related to space, weight and so on.
The producer of this new gadget is Power Plus and they have designed it to fit your needs at any time; they have even added a light for night usage.
Only then (in the dark) will you consume batteries; in the rest of the time, the sun will take care of its functioning. You can have the pressure of your tires displayed in bars, psi, kg/cm² or even kPa is you wish, but generally, its pressure range is from 0,15 bars to 10 bars.
The main advantage of keeping a right balance of pressure in your tires is the consistent amount of gas you can save; plus, the good traction of your tires will be guaranteed. As a result of that, the engine of your car will function at its maximum capacity. The orange LED light on your Power Plus Pelican will illuminate the tire, while the LCD has the same color as backlight.
Another thing you can check by using the device is how much wear you still have on your tires.