--- title: Diesel Truck Smog Check Questions in Nevada | Xpress Smog url: https://xpresssmogcenter.com/faq/diesel-trucks/ business: Xpress Smog Check Center (Located inside Xpress Oil & Lube Center) locations: Reno Northwest: 6100 Mae Anne Ave, Reno, NV 89523, (775) 787-1000, Mon-Fri 8 am-5 pm, Sat 8 am-4 pm, Sun closed; Reno South: 4993 Longley Ln, Reno, NV 89502, (775) 828-6996, Mon-Fri 8 am-5 pm, Sat 8 am-3 pm, Sun closed type: Nevada smog check (vehicle emissions inspection), drive in, no appointment --- Located inside Xpress Oil & Lube Center - Smog check at two Reno locations - Oil change in the same visit - No appointment needed [Xpress Oil & Lube](https://xpressoilandlube.com/) - [Home](https://xpresssmogcenter.com/) - [Questions and answers](https://xpresssmogcenter.com/faq/) - Diesel truck questions # Diesel truck questions Under DMV rules a diesel based in urban Washoe needs a yearly test when its manufacturer's gross vehicle weight rating is 14,000 pounds or less. Call the service center before you bring a diesel, so the staff can tell you what to expect. 4.7 stars from 550 Google reviews of the two Reno Xpress Oil & Lube Centers Diesel rules depend on weight and on where the truck is based. This page explains the DMV's rules and sends you to the phone before you make the trip. ### Do diesels need a smog check in Reno? Yes, when they meet all of the DMV's criteria: a GVWR of 14,000 pounds or less, based in the urban areas of Clark or Washoe, and model year 1968 or newer. New vehicles are exempt for the first three registrations and tested at the fourth. ### What is in a light-duty diesel test? The DMV describes a comprehensive inspection with a dynamometer test, an opacity test measuring exhaust density and a visual inspection of emission components. ### Which weight does the DMV use? The manufacturer's gross vehicle weight rating. The DMV says it may differ from the declared weight used for registration fees, so check your renewal notice to see whether a smog check is required. ### What about a diesel over 14,000 pounds? Those are not required to take the annual smog check but are subject to statewide roadside enforcement, based on the DMV. Sworn officers use the SAE J1667 snap acceleration test for exhaust opacity at traffic stops, highway check sites and weigh stations. ### Does the roadside rule cover trucks from other states? Yes. The DMV says the standards apply to all vehicles traveling in Nevada, including those registered in other states. ### Can I get my diesel tested at your Reno locations? Please call the service center before you bring a diesel. Reno Northwest is at (775) 787-1000 and Reno South is at (775) 828-6996. The staff will tell you what to expect for your truck. ### How long is a diesel test result good for? The DMV says 90 days for most tests and 180 days when the vehicle was purchased from a Nevada dealer. ### Is a diesel pickup treated like a gas pickup? Not the same way. Gasoline vehicles get a tailpipe or OBD inspection depending on model year, while light-duty diesels get the dynamometer, opacity and visual test described above. ### What if I am unsure whether my diesel needs a test? The DMV says to contact its emission lab. In Reno that is (775) 684-3580, at 9155 Double Diamond Pkwy. For heavy-duty diesel questions the DMV lists (775) 684-3562. ### Where can I read more about diesel testing? See the [diesel smog check page](https://xpresssmogcenter.com/smog-check/diesel-smog-check/) and the [diesel opacity and dynamometer guide](https://xpresssmogcenter.com/guides/diesel-opacity-and-dyno/). ### Does a diesel pickup that tows a trailer count the trailer? The DMV rule uses the vehicle's own manufacturer's GVWR. Look at the sticker on the driver's door jamb and compare it with 14,000 pounds. ### What if my renewal notice does not list a test? Follow the notice. The DMV says to check your renewal notice to see if a smog check is required, since the weight rating on file decides it. ## Before you drive the truck over Have your GVWR and model year handy, plus your renewal notice. A short phone call to the service center saves a trip, and it lets the staff answer questions about your particular truck. If your diesel is over 14,000 pounds, the annual test does not apply under the DMV rules, but the roadside opacity standards do, and they apply statewide. ## Why the dynamometer and opacity steps exist A light-duty diesel is checked differently from a gas car because its pollution looks different. The DMV measures exhaust density with the opacity test, and the dynamometer lets the truck run under load during the test. The visual inspection looks over the emission components. Because the equipment and the vehicle size matter, the safest move is a phone call before you drive in. Ask the service center at (775) 787-1000 or (775) 828-6996 about your specific truck. ### Sources - [dmv.nv.gov/emission_diesel.htm](https://dmv.nv.gov/emission_diesel.htm) (Nevada DMV diesel testing and enforcement; read 10/19/26) - [dmv.nv.gov/emission.htm](https://dmv.nv.gov/emission.htm) (Nevada DMV Emission Control Program; read 10/19/26) ## More questions by topic [Who needs a smog check in Nevada](https://xpresssmogcenter.com/faq/who-needs-a-smog-check/)[Where in Washoe County a test is required](https://xpresssmogcenter.com/faq/smog-check-areas-washoe/)[The renewal notice and the smog line on it](https://xpresssmogcenter.com/faq/renewal-notice/)[Your result and the DMV link](https://xpresssmogcenter.com/faq/certificate-and-dmv-link/)[How long a passing test is good for](https://xpresssmogcenter.com/faq/90-day-rule/)[Renewing your registration with the smog check](https://xpresssmogcenter.com/faq/renewing-at-the-station/)[What a smog check costs](https://xpresssmogcenter.com/faq/price-and-fees/)[Driving in without an appointment](https://xpresssmogcenter.com/faq/drive-in-no-appointment/)[Hours and the quiet times to come in](https://xpresssmogcenter.com/faq/hours-and-busy-times/)[Which service center to use](https://xpresssmogcenter.com/faq/which-service-center/)[An oil change in the same visit](https://xpresssmogcenter.com/faq/oil-change-same-visit/)[Check engine light questions](https://xpresssmogcenter.com/faq/check-engine-light-questions/)[After a failed test](https://xpresssmogcenter.com/faq/failed-test-questions/)[Smog waiver questions](https://xpresssmogcenter.com/faq/waiver-questions/)[Not ready and rejected results](https://xpresssmogcenter.com/faq/not-ready-questions/)[After a battery change or a repair](https://xpresssmogcenter.com/faq/battery-and-recent-repairs/)[Gas caps and small fixes before a test](https://xpresssmogcenter.com/faq/gas-cap-and-quick-fixes/)[Insurance trackers and OBD port devices](https://xpresssmogcenter.com/faq/obd-port-devices/)[New vehicles and the first three registrations](https://xpresssmogcenter.com/faq/new-vehicles/)[Hybrid and electric vehicle questions](https://xpresssmogcenter.com/faq/hybrids-and-evs/)[Diesel truck questions](https://xpresssmogcenter.com/faq/diesel-trucks/)[Motorhomes and heavier gas trucks](https://xpresssmogcenter.com/faq/motorhomes-and-heavy-trucks/)[Classic car and Old Timer plate questions](https://xpresssmogcenter.com/faq/classic-cars/)[Motorcycles and other exempt vehicles](https://xpresssmogcenter.com/faq/motorcycles-and-exempt/)[Moving to Reno or Sparks](https://xpresssmogcenter.com/faq/moving-to-reno/)[Leaving Nevada or living away part of the year](https://xpresssmogcenter.com/faq/leaving-nevada/)[Military members and students](https://xpresssmogcenter.com/faq/military-and-students/)[Private party sales](https://xpresssmogcenter.com/faq/private-party-sales/)[Buying from a Nevada dealer](https://xpresssmogcenter.com/faq/dealer-sales/)[Smoking vehicles and visible exhaust](https://xpresssmogcenter.com/faq/smoking-vehicles/)[Engine swaps and modified vehicles](https://xpresssmogcenter.com/faq/engine-swaps-and-modifications/)[Registered outside the Washoe testing area](https://xpresssmogcenter.com/faq/registered-outside-the-testing-area/) ### Your location: Reno South - Call [(775) 828-6996](tel:+17758286996) Mon-Fri 8 am-5 pm, Sat 8 am-3 pm, Sun closed - Address 4993 Longley Ln, Reno, NV 89502 [Directions](https://www.google.com/maps/dir/?api=1&destination=4993+Longley+Ln%2C+Reno%2C+NV+89502&destination_place_id=ChIJc5xNCcI_mYARXjHn3y79iJw) ### Related - [Diesel smog check rules](https://xpresssmogcenter.com/smog-check/diesel-smog-check/) - [Light-duty diesel testing: dynamometer and opacity](https://xpresssmogcenter.com/guides/diesel-opacity-and-dyno/) - [Motorhomes and heavier gas trucks](https://xpresssmogcenter.com/faq/motorhomes-and-heavy-trucks/) - [Reno Northwest smog check](https://xpresssmogcenter.com/locations/reno-mae-anne/) - [Reno South smog check](https://xpresssmogcenter.com/locations/reno-longley/) Located inside Xpress Oil & Lube Center Both smog check locations sit inside an Xpress Oil & Lube Center, the locally owned Reno drive-in that has served this town since 1983. Drive in, no appointment; get your oil changed in the same visit. [About us](https://xpresssmogcenter.com/about/)