Many truck committee meetings start with the chassis and the drive train. So, what engine do you need?
Most engine manufacturers have three basic engine sizes that are approved for the fire service generally around a 9 liter, a 12 liter, and a 15 liter, plus or minus liter size depending on the engine manufacturer.
For fire apparatus, 99% of the time, Torque is what is important for making your new apparatus perform correctly. Torque gets the truck moving out the door and provides the acceleration needed to obtain road speed.
Horsepower, on the other hand, is what moves the truck faster and keeps the apparatus speed up while driving.
Torque and Horsepower work in conjunction with each other, so as the vehicle is being driven, the engine may be working more in the Torque range under acceleration or breaking, or it may be working more in the Horsepower range to maintain cursing speed, or at times in both ranges.
Why is this important to know?
The larger the engine the more it costs and some of the price differences between engine sizes can be very significant. Do you really need to spend an extra $15,000.00 or more for a larger engine when it is not necessary? How do you know?
Spend time working with your sales representatives as they, in conjunction with the manufacturers they represent, can help you determine the right engine fit for the apparatus you are spec’ing and at the right cost for your budget. They can determine torque and horsepower needs along with acceleration/speed requirements for hill and long grade applications. Utilize each apparatus manufacturer’s vast database of knowledge to help you make the best engine purchasing decision possible.
For fire and rescue apparatus, bigger may not be better, just more costly, for something you may not need.
Scott Zingaro is a Regional Account Manager with Goodman Specialized Vehicles. Contact Scott