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Pierce Impel vs Velocity Custom Chassis

Pierce Manufacturing asked firefighters to help configure the ideal fire truck for both safety and efficiency, from the broadest concepts to the smallest details. The final list of firefighter specifications helped Pierce create its strongest and most innovative custom chassis — Impel® and Velocity®.

The Impel and Velocity chassis are the industry’s most heavy-duty fire chassis, featuring 13-⅜ inch frame rails. A heavy-duty fire apparatus is ideal when a large engine and increased horsepower is required; in environments with hills and steep inclines, and where added strength and durability is required.

With many similarities, the Impel and Velocity chassis can offer your department rugged durability, horsepower, and strength. Get to know the similarities and differences of the Impel and Velocity heavy-duty chassis below.

What are the Similarities?

1. Heavy-Duty Chassis Design

Perhaps the most striking similarity that sets the Impel and Velocity apart from every other chassis on the market is the frame construction. The chassis sits on 13-⅜ inch frame rails, the largest, strongest, and stiffest in the industry. As a result, Impel and Velocity transmit less stress to the vehicle body.

The key advantages of heavy-duty frame rails are:

  • Reduced apparatus wear and tear
  • Enhanced apparatus longevity
  • A smoother ride quality

Pierce Velocity and Impel Frame Rails

2. Large Interior Cab

Pierce has used every inch of space in the 100-inch wide cab to ensure firefighters have optimal leg, head, shoulder, and hip room. In fact, the chassis can hold up to 10 occupants.

Interior of Cab for Velocity and Impel Custom Chassis Carry 10 Personnel

3. Designed for Increased Visibility

The Impel and Velocity chassis offer exceptional visibility with the following design features:

  • A panoramic windshield offers a large single-piece bonded windshield and daylight windows for increased visibility. With no outside curves of the glass, there is minimal distortion in the corners, so the driver can clearly see the road, traffic, and pedestrians.
  • A three-blade wiper system improves visibility in inclement weather.
  • Pierce’s One-Eleven Mirrors offer excellent visibility around the vehicle. The mirrors are positioned to minimize the required body and head movements of the driver and to improve overall visibility.

Velocity Impel Chassis three blade wiper system coverage panoramic windshield

4. Maintenance

The Impel and Velocity chassis offer fire departments both ease of maintenance and low cost of ownership. The custom chassis features a Fast Access Service Tilt (FAST) hood, which is an innovative one-piece, full-width, lift-up hood that makes routine maintenance of fluid levels and wipers quick and easy. Engine and transmission checks are done through the engine tunnel right inside the cab, so you no longer have to tilt the cab to perform routine maintenance.

Heavy duty Chassis Velocity and Impel One piece full width lift-up hood

5. Wide Cab Doors and Handles

Generously sized door handles and forward cab doors are added ergonomic features in these custom chassis.

  • Extra-large interior and exterior door handles can be easily gripped by gloved hands.
  • Wide cab doors make vehicle exit and entry safe and quick for firefighters.

Velocity and Impel Custom Chassis Large exterior door handles

What Are the Differences?

The main differences between the Impel and Velocity concern the body configurations available on each custom chassis and the available engine size and horsepower. Velocity can support much heavier body configurations and larger aerial products, including the Ascendant® class of aerial products. Impel is available with single axle Ascendant products.





Cummins L9 

Detroit Diesel DD13, Cummins X15, X12 or L9 

Engine HP 370 – 450 hp  370 – 600 hp 
Transmission Allison EVS 3000 Allison EVS 3000, 4000 or 4500 
Alternator 270 – 430 amp 270 - 430 amp
Front GAWR (max) 23,000 lb  24,000 lb
Rear GAWR (max) 54,000 lb   60,000 lb
Cab Length

60”, 70”, 84” 

60”, 70”, 84” or 104” inch split-tilt

Cab Width 100" 100"
Body Configurations
  • Aerials
    • Single axle 75' aluminum ladder
    • Single / tandem axle 75' heavy-duty ladders
    • Tandem axle 105' heavy-duty ladder
    • Single / tandem axle 107' Ascendant® ladders
    • Single / tandem axle 110' Ascendant platforms
    • Sky-Boom water tower
  • Single / tandem axle pumpers
  • Single / tandem axle rescues
  • Single / tandem axle tankers
  • Aerials
    • Single axle 75' aluminum ladder
    • Single / tandem axle 75' heavy-duty ladders
    • Tandem axle 100' aluminum ladder
    • Tandem axle 100' heavy-duty ladder
    • Tandem axle 105' heavy-duty ladder
    • Single / tandem axle 107' Ascendant ladders
    • Tandem axle 100' aluminum platform
    • Tandem axle 100' heavy-duty platform
    • 100' Ascendant tower
    • Single / tandem axle 110' Ascendant platforms
    • 107' Ascendant tiller
    • Sky-boom water tower
  • Single / tandem axle pumpers
  • Single / tandem axle rescues
  • Single / tandem axle tankers

If your department is seeking a heavy-duty apparatus with the ability to power through tough conditions, the Impel or Velocity may be the right choice for you. With a very similar chassis, each has the flexibility to meet the unique needs of your department.

Download the Impel and Velocity custom chassis brochures for more information.

We want your input, which custom chassis do you prefer?

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Topics: Products

About Pierce Manufacturing
Pierce Manufacturing Inc., an Oshkosh Corporation [NYSE: OSK] company, is the leading North American manufacturer of custom fire apparatus, including custom and commercial pumpers, aerials, rescue trucks, wildland trucks, minipumpers, elliptical tankers, and homeland security apparatus. In addition, Pierce designs its own foam systems and was the first company to introduce frontal airbags and the Side Roll Protection system to fire apparatus. Pierce markets its products through the industry’s largest and most comprehensive dealer and service network. The company enjoys a nationwide web of dealerships with over 600 certified and factory trained Service Brigade technicians and over 50 service centers. Visit to learn more about Pierce.

About Oshkosh Corporation
Founded in 1917, Oshkosh Corporation is 100 years strong and continues to make a difference in people’s lives. Oshkosh brings together a unique set of integrated capabilities and diverse end markets that, when combined with the Company’s MOVE strategy and positive long-term outlook, illustrate why Oshkosh is a different integrated global industrial.  The Company is a leader in designing, manufacturing and servicing a broad range of access equipment, commercial, fire & emergency, military and specialty vehicles and vehicle bodies under the brands of Oshkosh®, JLG®, Pierce®, McNeilus®, Jerr-Dan®, Frontline™, CON-E-CO®, London® and IMT®.

Today, Oshkosh Corporation is a Fortune 500 Company with manufacturing operations on four continents. Its products are recognized around the world for quality, durability and innovation, and can be found in more than 150 countries around the globe.  As a different integrated global industrial, Oshkosh is committed to making a difference for team members, customers, shareholders, communities and the environment. For more information, please visit

®, TM All brand names referred to in this news release are trademarks of Oshkosh Corporation or its subsidiary companies.

Forward-Looking Statements
This press release contains statements that the Company believes to be “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. All statements other than statements of historical fact, including, without limitation, statements regarding the Company’s future financial position, business strategy, targets, projected sales, costs, earnings, capital expenditures, debt levels and cash flows, and plans and objectives of management for future operations, are forward-looking statements. When used in this press release, words such as “may,” “will,” “expect,” “intend,” “estimate,” “anticipate,” “believe,” “should,” “project” or “plan” or the negative thereof or variations thereon or similar terminology are generally intended to identify forward-looking statements. These forward-looking statements are not guarantees of future performance and are subject to risks, uncertainties, assumptions and other factors, some of which are beyond the Company’s control, which could cause actual results to differ materially from those expressed or implied by such forward-looking statements.

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