Before describing the steps in spec'ing, we need to put a few aspects of the process in perspective.
BA = Bumper to Axle
BBC = Bumper to Back of Cab
BL = Body Length
CA = Cab to Axle
CB = Cab to Body
CE = Cab to End of Frame
FH = Frame Height
LA = Load to Axle
OAL = Overall Length
WB = Wheelbase Actually, understanding the dimensions is relatively simple. It's the lack of technical knowledge that limits the novice, such as the relationship of horsepower to desired road speed or axle ratio or torque. Leave these calculations to the professional. Your job is to gather information by asking the right questions and communicate what you have learned to the vendor you have chosen to partner with. In fact, that partner should be acting as a consultant, walking you through the process and working on your behalf. Identifying a good one is critical and probably one of the most important choices you will have to make. Five-Step Approach To Spec'ing Trucks
Understand the application requirements
This along with the operating parameters is at the heart of the matter. You must have a clear understanding of what this vehicle is expected to do and how.
Gather information from the field. Talk to the drivers or technicians and ask questions. If need be, schedule site visits to see firsthand what use the truck is being put to and to confirm what is really needed as opposed to what an operator may want.
Will the GVWR (gross vehicle weight rating) satisfy the payload requirements? If towing a trailer, is the GCWR (gross combined weight rating) adequate?
It is surprising how many fleets don't actually know what their payload needs are. If necessary, have a fully loaded unit weighed. Ideally, you should add a reserve capacity of approximately 20 percent to the maximum payload.
What are its dimensions? Will it be loaded on pallets? Can it be stacked, and if so, how high?
What is the nature of the product carried? Is refrigeration required? Is it palletized boxes or loose sand? This will dictate the truck/body combination you will need.
Will it be loaded at a dock? What is the height? Will a forklift be used? If so, what door opening height is needed? Will a liftgate be required? Will a side door be needed for off-loading? What type? Step 2:
Understanding the operating parameters
This is the "how" portion of the heart of the matter and equally important.
Will it be operated fully loaded or with a diminishing load?
Where will the unit be utilized? Will it be in mountains or extreme weather?
There are multiple factors under this heading including: desired cruising speed, desired startability, desired high gear gradeability and cruising speed and vehicle configuration. This is one of those areas where you can leverage off the experience and knowledge of your chassis provider to help make decisions as to what vehicle configuration best suits your needs.
Review maintenance records of an existing truck in the same application. Are they reasonable or can you identify problems? Most vehicles suffering repeat or related failures are under spec'ed. Again, talk to the drivers. Step 3
Select the chassis
Knowledge gained of application requirements and operational parameters can now be used to choose an appropriate chassis. Below are listed some of the key considerations. This is another area where you will need to work closely with your chassis provider.
GAWR is important because the certified GVWR is determined by the lowest rating of the load carrying components which include the frame, springs/suspension, axles and tires. Contrary to what most novice buyers believe, that's usually tires.
Is there a shop in the area to handle repair or warranty work? It makes little sense to purchase a brand name with no support in the area in which the vehicle is operated.
Besides the DOT regulations you must be aware of state and local statutes. Be sure to check if any have chnaged since your last truck was purchased. Listed here are some of those most frequently encountered.
Determine if the cargo you are handling falls under one of the rules governing hazardous material. If so, make sure you are conforming to the law. Step 4:
Select the powertrain
The powertrain consists of the engine, transmission, driveline, rear axle, wheels and tires.
Again, refer to the application requirements and operating parameters. They will drive the choice of components. This is another area where your chassis provider will be indispensable. Some considerations are:
Will the unit be operated in the mountains or at extreme temperatures?
Includes desired cruising speed, startability, high gear gradeability and cruising speed. Speed ranks right behind payload in importance when spec'ing trucks. It affects horsepower requirements, guides engine and transmission selection, is a factor in axle ratio selection and the basis for many other powertrain specifications such as engine rpm and engine governors.
Will the vehicle be operated on highway surfaces or off-road sites?
Will it be operated in stop and go city traffic or open highways? Step 5:
Select the body
We're back to the pillars of truck spec'ing - application requirements and operating parameters and the last step in the process. You will need to work closely with your chassis provider and/or body company to be sure the end product meets your needs. Below are just some of the considerations.
What is your cargo? Obviously the type, volume and weight of the product drive the body. Are there refrigeration requirements?
Are you loading at a dock? If so, what is the height? Are there specific rear and/or side door requirements? Will you be using a fork lift? Is a liftgate or ramp needed?
How will you secure the load? Common Mistakes to Avoid
Using what you have learned about the fundamentals of truck spec'ing in managing the process should help you avoid some of the most common errors. But just in case, here is alist of frequently made mistakes, the consequences associated with them and a strategy to avoid the problem.
1. Not understanding the application and/or upfit
This is the basis of most common errors. It will result in vehicles not optimally configured for the job; ultimately resulting in higher costs. As outlined previously, do the background work and talk to your people in the field. Consult with providers.
This is the most commonly made error. It is frequently a result of avoiding the 26,000-lb. CDL requirement or not considering additional equipment needs. It will increase maintenance costs and downtime while decreasing efficiency. It also increases your liability risk.
Know your application requirements - especially payload.
This does nothing but increase your capital cost.
4. Buying vehicles under 26,000 lb. GVWR but with air brakes/Driver does not have endorsement
Be aware of federal and state regulations. Avoid dealers who just want to sell you what they have in stock, rather than what you really need.
5. Chassis misapplied -- on-/off-road applications
Using a chassis for off-road use not properly spec'ed may cause warranty, liability or mechanical problems. Know your operating parameters. Consult with your providers.
6. Not understanding your finance options
This can result in higher capital costs or cash flow than necessary. Research applicable purchase/fleet rebates and incentives. This can save you thousands of dollars, and is well worth the time invested. Research the various lease options (open, closed, TRAC, buy-backs). Consult with your providers.
7. Ordering "the same truck as the last one"
Relying only on past specs puts you in jeopardy when things change. Consult with your field people. Verify that applicable local/federal regulations have not changed. Consult with your providers.
8. Lack of planning resulting in buying what is available rather than what you want or need
Not planning ahead can cost you a premium. Understand lead times for vehicle chassis and body building. Consult with your providers. Concentrate on the Critical Elements
While all of the information presented here can be helpful at some time, it's unlikely you will remember everything covered. So concentrate on the most critical elements.
Know your application requirements and operating parameters -- especially maximum payload. Talk to your drivers and technicians to understand desired performance criteria -- especially speed.
Research provider options and settle on one willing to act as consultant and willing to leverage on their knowledge and experience. Doing these things should allow you to manage the process. Editor's note: Wayne J. Reynolds is manager, corporate fleet trucks for LeasePlan USA, a subsidiary of ABN AMRO Lease Holding.