It is more like car length than seconds when following another car. You should be at least 2 car lengths from the other car.
You double your distance in the rain. the seconds method is only a practices guide for beginners.
You should be 2-3 seconds behind a given point that the vehicle in front just passed. At 65 mph, that is 95 feet per second, so multiply by 2 or 3 and you should be 190-280 feet behind
Allow a minimum of 3 seconds of braking distance at 55 MPH, add an extra second for each 5 MPH increase in speed.
The rule of thumb is: Prefered is Four seconds, Minimum 2 seconds. If you are texting: Prefered 4 Hours Minimum 2 hours
You should always remain a safe distance when you are behind another vehicle. The recommended amount of space that you should leave is one and half car lengths.
At minimum 3 seconds. If the road conditions are adverse, it should be 5 seconds or more.
They say to be about 3 seconds behind the person infront of you. So the faster you move the further back you should be.