Diesel Smog Test
Las Vegas. One Location. Done Right.

What a Diesel Smog Test Is

A diesel smog test checks how clean your diesel engine burns fuel. But it works nothing like the gasoline smog check most people are familiar with. There is no OBD-II port to scan, no computer readout of engine codes. Instead, your vehicle goes on a dynamometer at the E Sahara corporate hut, and a certified diesel technician runs what is called a Snap Acceleration Test.

During the test, the technician rapidly accelerates the engine under controlled conditions while a device called an opacity meter reads the exhaust. That meter measures how much light gets blocked by the smoke coming out of the tailpipe. If your exhaust blocks too much light, the vehicle fails. If it passes, you get a valid Nevada emissions certificate.

The official test procedure is called SAE J1667. It is the standard Nevada uses for diesel emissions, and it requires specialized equipment that most smog shops do not have. That is why diesel testing is limited to certified stations with a D rating and a dynamometer.

Which Diesel Vehicles Need Testing

Not every diesel vehicle needs a smog test. Nevada requires diesel emissions testing for vehicles that meet all of these conditions:

• Diesel-powered engine. Gasoline vehicles go through a completely different test process at any of the 32 Smog Busters locations.
• Gross vehicle weight rating (GVWR) of 14,000 lbs or less. This covers most diesel pickups like the Ford F-250, Ram 2500/3500, Chevy Silverado 2500/3500, and Mercedes Sprinter vans. Vehicles over 14,000 lbs GVWR are exempt from station testing, though they are still subject to roadside enforcement.
• Registered in Clark County or Washoe County. If your vehicle is registered in a rural Nevada county, it is exempt from emissions testing.
• Model year 1968 or newer. Vehicles older than model year 1968 are exempt.

How the Diesel Smog Test Works

Here is what happens when you pull into the E Sahara location for a diesel smog test:

• Check-in. A technician verifies your registration and vehicle information. The vehicle must be present for the test.
• Dynamometer setup. Your diesel pickup or Sprinter van is positioned on the dynamometer. This is a roller system that lets the drive wheels spin while the vehicle stays in place.
• Warm-up. The engine needs to be at operating temperature. If you drove to us, it is probably already warmed up. If not, the tech will idle it until it reaches the right range.
• Snap Acceleration Test. The technician rapidly opens the throttle from idle to full throttle under load. This is repeated several times. The opacity meter reads the exhaust during each snap.
• Opacity reading. The meter calculates the average opacity across the test snaps. Nevada sets a maximum opacity percentage. If your average is below that threshold, you pass.
• Results. You get your pass or fail result on the spot. A passing result is valid for 90 days, or 180 days if the vehicle was purchased from a Nevada dealer.

The entire process typically takes 15 to 30 minutes depending on the vehicle and whether it needs warm-up time.

What to Bring

Have these ready before you head to E Sahara:

• Your diesel vehicle. The vehicle must be physically present for the test. Unlike some DMV paperwork, a diesel smog test cannot be done without the vehicle on the dynamometer.
• Current Nevada registration. This confirms the vehicle is registered in Clark or Washoe County and shows whether the smog is due.
• Photo ID. Nevada driver’s license or state ID.
• Payment. Call us for current diesel smog test pricing.

Diesel vs Gasoline Smog Testing

Diesel owners sometimes wonder why they cannot just go to any smog shop. The reason is that diesel and gasoline emissions testing are completely different procedures that require different equipment, different certifications, and different training.

• Gasoline test: Uses an OBD-II scanner to read the vehicle’s onboard computer. Checks engine codes, monitors, and readiness. Available at all 32 Smog Busters locations. Takes about 10 minutes.
• Diesel test: Uses a dynamometer and opacity meter. No computer scan. Physical measurement of exhaust smoke density under load. Only available at E Sahara. Takes 15 to 30 minutes.
• Gasoline certification: 1G (inspection) or 2G (inspection + repair). Most smog shops hold at least a 1G.
• Diesel certification: D rating. Requires specialized training and equipment. Very few stations in the valley hold this rating.

Bottom line: if your vehicle runs on diesel, you need a station with a D rating and a dynamometer. The E Sahara location has both.

Getting to E Sahara From Across the Valley

The E Sahara corporate location is centrally located at 2711 E Sahara Ave, Las Vegas NV 89104, near the intersection of Sahara and Eastern.

From Summerlin: Take Sahara Ave east across the valley. It is a straight shot, about 20 to 25 minutes depending on traffic.

From Henderson: Take the 215 to the 515/US-95 north, exit at Sahara Ave and head east. About 20 minutes.

From Spring Valley: Head east on Flamingo or Tropicana to the Strip area, then north on Eastern to Sahara. About 15 minutes.

From North Las Vegas: Take Las Vegas Blvd south or the 95 south to Sahara Ave, then head east. About 15 to 20 minutes.

Walk in any day during business hours. Monday through Friday 8am to 6pm, Saturday 8am to 4pm. No appointment needed, but appointments save $10.*

*$10 appointment discount applies to full service fees. $10 analyzer renewals not included.

Get directions on Google Maps.