In this case study we will focus on the topic of improved fuel consumption and provide some hard evidence to prove how the system can reduce a direct cost.

The vehicle in question, to which the Zone Safe II is fitted, is a Mercedes Econic based, trade waste refuse collection vehicle, operated by one of our municipal customers.

In this instance the system has been employed to stop the ‘Park Brake’ from being released once the driver has left the cab and then to stop the engine thirty seconds after the driver/operator has left the detection fields at the rear of vehicle/cab. The thirty second delay has been implemented at the request of the customer, to allow the completion of the hydraulic compaction cycle. The engine will then automatically restart when the driver/operator approaches within 4-5m of the rear of the vehicle or renters the vehicle cab.

The vehicle is a ‘single manned operation’ and collects trade waste from mainly high street, retail establishments and schools. The collection process involves short periods of driving between the collection points. When a collection point is reached, the driver will exit the vehicle, walk a short distance to collect the waste bin and then return to the vehicle to process it.

In most cases the driver will not leave the vehicle unattended for long periods and more often than not it will still be within his/her line of sight.

Therefore, in this case study, the instances where the system actually intervenes and stops the engine are relatively infrequent and

the increase in fuel economy is relatively small in percentage terms, but the following calculations illustrating the actual savings in monetary terms are quite thought provoking.

The facts and figures

• Average monthly mileage covered by the vehicle = 1,250 miles
• Fuel economy prior to the installation of the Zone Safe II system = 4.0 MPG
• Bulk fuel (diesel) price paid by customer
  = £1.00 per litre
• Therefore 1,250 miles @ 4.0 mpg = 312.5 gallons used
• 312.5 gallons x 4.5 (litres per gallon)
  = 1,406.25 litres used
• The average cost to fuel the vehicle per month = £1,406.25
• Fuel economy post the installation of the Zone Safe II system = 4.2MPG

This equates to a saving of 5% in fuel economy.

Therefore a 5% fuel saving would equate to a monetary saving of £70.31 per month, per vehicle on this basis.

If we look at the cost saving over a 50 working week year average, the total saving is £811.27 per vehicle.

We have used the above example rather that one where fuel efficiency gains are much larger, to illustrate that even a small percentage gain can represent considerable saving when put into context.