A problem with deathmobile

Can anyone tell my why my current deathmobile is unable to keep the speed while driving (I have to modulate its speed by increasing or decreasing it each turn)? The car is missing green digits that usually display next to the blue ones, pic related. Sorry for the blurry description, I don’t really know how to explain my issue any better.![car_speed|690x387]

Explanatory pic:

Did you uncheck “Cruise Control” in the control options?
This can happend by an unintentional button press.
Cruise control lets the vehicle stay on the speed you accelerate to. Otherwise you have to accelerate all the time because you basically let the car roll out otherwise.

Or, if your deathmobile runs on solar power, maybe the batteries are low, so they repeatedly run our of fuel and only get power everytime the panels generate some. But then you would get the message “The vehicle is too heavy for its engines” because they don’t generate enough power.

Edit.: Just checked the picture: it is cruise control.

Otherwise you would have a green number next to your speed, that shows the desired speed value.

The wiki entry

Thank you! Probably I have accidentally turned it off, that really solved my problem mate. I’m pretty new to the game and every few hours I learn something new.