The Diesel Emission Quantifier should not be used for the calculation of any emission reductions to be incorporated in a State Implementation Plan (SIP) or conformity determination, and certain other technical applications. Please do not continue using the Quantifier until you have read the important usage information.

Complete Quantifier User's Guide (PDF, 42 pages, 152K, About PDF)

Step by step instructions for using the Quantifier

The following steps can be printed out and used to help guide you through each step in completing the Diesel Emissions Quantifier.

1) Figure 1 below shows the Start screen of the Quantifier. We recommend that you register for an account. Registering for an account is not required to use the Quantifier, but an account allows you to save up to three scenarios to work on at a later time, and allows you to produce a summary report. If you do not wish to create an account, you can skip ahead to step 4.

Figure 1: Quantifier Start Page

2) To register for an account on the Start screen, click on the Create a Password link. You will then see the form below.

Figure 2: Registering For an Account

3) Items marked with a red asterisk (*) are required to be completed before the account registration form can be submitted. Once this form is submitted, your account has been created and you will be redirected to the Start screen where you can select a scenario: quantifying emissions or preparing data for the EPA. Additionally, a state must be selected. If a project spans across multiple states, select the state that will receive the majority of the benefits.

Once you create and save scenarios, those saved scenarios will appear as new scenario options after you log in. You will also be presented with the contact information that the Quantifier has on file for your account, and you have the opportunity to add new information or correct any errors. Once you have reviewed your personal information, select a saved scenario and the state will be selected for you. You can then click on the Continue >> button to continue to the fleet entry screen.

Figure 3: Logged In

4) On the fleet entry screen, enter data about your fleet of vehicles and select what technology or technologies will be applied to each group of vehicles. As you select options on the fleet entry screen, the Quantifier will prompt you for any additional information that it needs to perform calculations and alter options available on the rest of the fleet entry form. For example, if you select highway for the type of vehicle, you will see School Bus as a possible sector of vehicle. However, if you select nonroad as the type of vehicle, you will not see School Bus as an option under sector. For more information about how emissions are quantified and how various technologies affect a vehicle, check out the User guide. The exact steps are as follows:

a) Select the type of vehicle - highway or nonroad.

b) Select the sector.

c) Select the type of vehicle.

d) Enter the number of vehicles in the fleet.

e) Select the engine model year for the vehicles in that fleet. If your fleet is made up of a mix of ages, you can select an average. However, the Quantifier will produce more precise results if you enter these vehicles as separate groups with the correct engine model year specified.

f) Select the retrofit year - the year in which the reduction technology will be installed.

g) Select the fuel type used by the vehicle group.

h) Enter the amount of fuel used by the entire fleet.

i) Enter any other information the Quantifier requests.

i) For on-highway vehicles, this will include the average number of miles driven per vehicle per year, and the number of hours each vehicle spends idling during the year.

ii) For nonroad vehicles, select the horsepower rating for the engine, or the nearest value if that engine's horsepwer is not an available option. Vehicle types that track the hours of usage will request a usage rate, which is the number of hours that the engine is run during a year.

j) If you would like the Quantifier to calculate the total cost effectiveness for the retrofit project, select "click here to enter funding information" and enter the funding amounts from each source of funding. If you do not wish to calculate this value, you can ignore this link.

k) Click on the save button to complete entering information for this vehicle group. You will now see this vehicle group listed at the bottom of the fleet entry page, under Current Vehicles and Applied Technologies. As you add vehicle groups, they will appear in this last section.

5) Apply emissions reduction technologies to this vehicle group. Available technology options will be limited to technologies that can be applied to the current vehicle group. Similar to entering a vehicle group, as you select a technology type and technology, options will vary and additional fields may appear. For example, if you select an idling control technology, you will be prompted for the number of hours that idling control will be in effect.

a) Select the technology type.

b) Select the actual technology. The percent reduction for each type of technology will be filled in by the Quantifier, based on US EPA and California Air Resources Board testing, and other pervious testing. The list of technologies is not comprehensive - the percent reduction fields can be edited to reflect technologies that are not found in the Quantifier.

c) Enter the number of vehicles to which you would like this technology applied.

As technologies are applied to a vehicle group, the Quantifier divides the vehicle group into subgroups with each subgroup have a unique combination of technologies. For example, a fleet of 400 buses is one vehicle group. If 200 buses have a diesel particular filter installed, two groups are created, one group of 200 buses with a filter installed and another group with no technology installed. These subgroups will be reflected in the section at the bottom of the page, Current Vehicles and Applied Technologies. Additional technologies can be applied to these subgroups.

Considering the example with 400 buses, if you attempt to install an idling control technology on this group of vehicles, you will see a box to enter the number of buses with the filter to install the control on, and the number of buses with no technology to install the control on. If idling controls were not compatible with diesel particulate filters, only an input box for buses that have no technology would be shown.

Figure 4: Mixing Technology

d) If you would like the Quantifier to calculate capital cost effectiveness, enter the unit cost and installation cost for each technology, otherwise, enter a zero. (0)

e) Click on the Save button.

f) Continue adding as many technologies as you need to.

6) Repeat steps four and five until all of your vehicle groups and emissions technologies have been entered.

7) If you have logged in, you may want to save your scenario by entering a name for the scenario and clicking Save Scenario. When you log in to the Quantifier in the future, this name will appear as a scenario that you can load.

Fig: Saving Scenarios

8) If you have not logged in, you will see a Log In link where the Save Scenario button appears in this example. If you would like to save your scenario, you simply need to click the Log In link, and then click the Create a Password link to register for an account. Once you have completed the registration form, you will be directed back to the welcome page. Select the scenario quantifying emissions and select the appropriate state, and when you click Continue >> your current scenario will appear under Current Vehicles and Applied Technologies. You can then save your scenario.

9) Once your fleet entry is completed, you can click the Quantify Emissions button. This takes you to the results page, where the Quantifier calculates the baseline emissions for your fleet, the baseline emissions for the vehicles retrofitted, and the amount reduced by the technologies specified.

Checklist of Needed Inputs:

Type of Vehicle
Fleet Count
Model Year
Retrofit Year
Current Fuel Type
Fuel Volume- gal/year for entire fleet
Vehicle Miles Traveled- miles/vehicle/year (On highway Only)
Hours spent idling-hours/vehicle/year (On highway Only)
Horsepower (Nonroad Only)
Usage Rate- hours/year (Nonroad Only)
Funding Amount (optional)
Technology Applied
New Model Year (if replacing engine/vehicle)
Idling Hours Reduced (if idling reduction is used)
Count of retrofitted vehicles
Cost of Technology (optional)
Installation Cost (optional)