2. SPECIFY

It is important to accurately configure your fleet vehicles. This helps to ensure that CWI product performance meets or exceeds your expectations. Your Cummins representative is available to help you make informed decisions on mission critical items.

Cummins Westport engines are available from many OEMs for a wide range of applications. Generally, we recommend the following:

  • ISB6.7 G for applications up to 33,000 lbs.
  • ISL G / ISL G Near Zero for vehicles up to 66,000 lb. GVW
  • ISX12 G for applications up to 80,000 lb. GVW and over 60,000 miles per year

The ISB6.7 G, ISL G and ISL G Near Zero engines are available with automatic transmissions, and the ISX12 G is available with manual, automanual and automatic transmissions.

When specifying your vehicles, consider things like duty cycle, desired cruising speed, grade, time on soft surfaces, etc. To provide guidance on gearing recommendations and/or calculations for a specified engine type, application and load, Cummins offers a free online tool called PowerSpec. Our representatives are trained to help you make the right selection. Click here for PowerSpec help.

Natural gas is uniquely different from diesel or gasoline, primarily because it is lighter than air. Vehicle fuel storage systems can be compressed (CNG) or liquefied (LNG) natural gas. There are several videos on this subject in the CWI Natural Gas Academy.

Many customers maintain “return to base” fleets where home base fueling is an option; others are on dedicated routes where public fueling is available. When specifying your fuel system, consider your fueling strategy:

  • Is yours a return to base operation?
  • Do you run a fleet of regional trucks that use public fueling?
  • What is the range required between fueling, including reserve capacity?
  • How is your fuel system configured?

Range and fuel system requirements can be found in the CWI Payback Calculator.  

Fuel systems must be designed to meet engine pressure requirements at the fuel connection to engine: 70 – 150 psi (ISB6.7 G), 75-150 psi (ISL G), and 65-150 psi (ISX12 G).

Pipeline natural gas fuel quality can vary on a regional and seasonal basis. LNG fuel quality may change if it is held in storage for extended periods of time. Consult your fuel provider on a regular basis to ensure that natural gas fuel quality, in particular, the methane number, meets engine requirements.  Cummins Westport natural gas engines have a fuel specification where the minimum Methane Number (MN) is 75. Customers can check the fuel quality in their area using the CWI Fuel Quality Calculator on the website.

With every CWI natural gas engine, Cummins provides a comprehensive Base Warranty. We also offer our customers a range of Extended Warranty Coverage options providing peace of mind for up to five years.

Please contact your OEM or local Cummins sales representation for details and pricing. If you would like us to follow up with you directly, please click here.