Four tests a year. What will it cost you?

Compare a credentialed tester with a CARB-certified device, using your truck's real Clean Truck Check deadlines.

What's changing

Today, most diesel trucks over 14,000 lbs need a Clean Truck Check test twice a year.
Starting October 1, 2027, trucks with full on-board diagnostics (OBD) move to four tests a year. That covers most diesel trucks with 2013 or newer engines.
The quarterly deadlines start January 1, 2028. You can send a test up to 90 days early, so the first quarterly tests start in October 2027.
Trucks entering California from other states must follow the same rules.

How your deadlines are set

Your deadlines are tied to your DMV registration expiration date.
Each deadline falls on the same day of the month as your registration date. If a month is shorter, the deadline is the last day of that month.
You can submit a passing test up to 90 days before each deadline. That's 90 days, not 3 months.

Credentialed tester

A CARB-credentialed tester runs the test for every deadline. Most charge $125 to $150 a visit. Four deadlines a year means four visits.

CARB-certified device

A small device plugs into the truck's OBD port. It tests the truck on its own and sends the results to CARB. You pay once a year, no matter how many tests.

Run your own numbers

This calculator starts from today's date and your registration date. It counts the tests your truck will actually need over the years you pick. Then it compares paying a tester for each test with the cost of a device.

DMV registration expiration date

Use the date on your registration card. Any year works. Out-of-state or exempt plates: enter one of your deadlines from CTC-VIS instead.

Number of trucks

Tester price per visit

Most testers charge $125 to $150.

Device with setup (first year)

Includes the device, setup and the first year of service. $1 to $600.

Annual plan (year 2 and after)

Yearly cost to keep the device testing. $1 to $600.

Other device vendors charge different amounts. Change these two prices to compare any vendor.

Years to compare

Your results

With a tester

With a device

Year by year

Year	Tests	Tester	Device

See your test deadlines

Deadline	Window opens	Schedule

The fine print

Not included: shipping, sales tax, repairs, and CARB's yearly compliance fee, which you pay either way.
A device works only on trucks with full OBD, and it stays with one truck (one VIN). Older trucks still need a tester.
If a test fails, a tester may need to come back. A device simply tests again after repairs. Retests are not counted here.
Deadlines and rules can change. Always check your official deadlines in CARB's CTC-VIS.