The rate at which a vehicle accelerates, normally declared as time taken between two speed points.
eg: 0 to 60mph in 4.8s
If you plot acceleration time, in this case 0-100km/h, versus the weight to power ratio for the car then you get an approximately straight line relationship.
0 to 100km/h time versus weight to power ratio. [red] = front wheel drive, [blue] = rear wheel drive
This now means that for a given maximum power and weight of a vehicle you can calculate the time the car will take to make the 0-100km/h sprint. The above graph shows front and rear wheel drive separately as this has quite an influence on the ability of the car to put the power down onto the road in extreme power to weight ratio cases.