New Mexico Combination Vehicles CDL Practice Test
Below are 25 exam-style questions for the New Mexico Combination Vehicles CDL knowledge test, modeled on the FMCSA-aligned content used by the New Mexico Motor Vehicle Division. Try to answer each question on your own before reading the answer key directly under it. The questions and answer choices are shuffled deterministically per state and endorsement, so the order will stay the same on repeat visits — that lets you genuinely measure your improvement.
- A The fifth wheel breaks
- B The trailer brakes lock up
- C The tractor brakes lock up
- D A wheel bearing fails
- A Brake adjustment levers
- B Manual transmission shifters
- C Electrical connectors
- D Coupling devices for connecting tractor air lines to the trailer
- A Stopping distances increase and the trailer can swing
- B Steering becomes easier
- C Stopping distances are normal
- D No effect on safety
- A Air leakage in the supply line, low pressure, or a brake-balance issue
- B Cargo placement
- C Driver fatigue
- D Engine wear
- A They take more skill to back, couple, and uncouple
- B All of the above
- C They are heavier and longer
- D They have a higher rollover risk
- A Listening to the brake light
- B Pressing the pedal once at startup
- C Asking a mechanic
- D Performing the seven-step air-brake check before each trip
- A Stops only with parking brake
- B Stops faster than when loaded
- C May actually take longer to stop because brakes are designed for the loaded weight
- D Stops in the same distance
- A Air for the brakes
- B Hydraulic fluid
- C Fuel
- D Electrical power for trailer lights and ABS
- A Cargo placement
- B Lane positioning at intersections
- C The fuel mileage
- D The trailer following the same path as the tractor in a straight line
- A The parking brake
- B The tractor service brakes only
- C The trailer service brakes only
- D Both tractor and trailer brakes simultaneously
- A Cuts, abrasions, and worn seals
- B Loose lug nuts only
- C Engine oil leaks
- D Cargo placement
- A All of the above
- B Off-tracking on right turns
- C Trailer sway in crosswinds
- D Reduced visibility along the trailer
- A Driving off the road
- B Loss of traction
- C The trailer wheels follow a tighter arc than the tractor wheels in a turn
- D Sliding sideways
- A Released and visible after coupling
- B Locked and the safety latch in place after coupling
- C Removed before driving
- D Tied with rope
- A One second per 10 feet of vehicle length below 40 mph, plus one extra second above 40 mph
- B A vehicle length
- C Two car lengths
- D No specific rule
- A Stay in the right lane and swing the front of the tractor wide enough to clear the curb without inviting cars to pass on the right
- B Use the shoulder
- C Turn from the left lane
- D Stop traffic by signaling left
- A Carries electrical power
- B Sends air pressure to apply trailer service brakes
- C Drains the trailer reservoir
- D Sends supply air to the trailer reservoirs
- A Tug the trailer with the trailer parking brakes set
- B Look at the locking jaws only
- C Honk the horn
- D Listen for a click
- A Back at full speed
- B Have the dispatcher in the cab
- C Use only mirrors
- D GOAL — Get Out And Look — and walk around the trailer first
- A No specific order is required
- B Pull tractor away first, then disconnect lines
- C Lower landing gear, disconnect lines, release fifth wheel, pull tractor away
- D Release fifth wheel first, then connect lines
- A Connect the lines back to the tractor
- B Disable the trailer parking brake
- C Check that the trailer is stable on its landing gear
- D Move the tractor far away immediately without checking
- A Driving too fast for conditions and/or too closely
- B Engine failure
- C Cargo movement
- D Worn out tires
- A The horn will sound
- B You will notice immediately because trailer brakes will not work properly
- C Nothing will happen
- D The trailer brakes will be locked on
- A Pulling, sticking, or unusual feel as you apply the brakes
- B Engine knocking
- C Steering wander only
- D Smoke from the cab
- A Apply trailer brakes momentarily
- B Test the trailer brakes
- C Both for parking and to prevent jackknife
- D Hold the vehicle when parking
Study tips for the New Mexico Combination Vehicles exam
The Combination Vehicles portion of the New Mexico CDL exam is graded out of the bank of questions the New Mexico Motor Vehicle Division draws from each year. While the exact bank is not published, every question is sourced from the Combination Vehicles chapter of the New Mexico CDL handbook, which itself is derived from the FMCSA Model Commercial Driver's License Manual. That means studying our practice tests, reading the corresponding handbook chapter, and re-reading the parts you got wrong is genuinely the most efficient route to a first-time pass.
Most successful applicants follow a simple cycle: take the practice test cold, write down every question you missed, open the matching chapter of the official New Mexico handbook, re-read the section that contains the right answer, then re-take the practice test 24 to 48 hours later. The 24-hour delay matters — sleep is when your brain commits new information to long-term memory, and CDL knowledge questions reward that kind of consolidated learning rather than cramming.
Pay particular attention to questions that include qualifier words like always, never, only, primary, or most. CDL test writers love to flip the right answer with a single qualifier. When two answer choices look almost identical, pay attention to the verb (is it must, should, or may?) and to any numbers (14 days, 100 air miles, 8 hours, 70/8 split). On endorsement tests in particular, watch for trick framing where a true statement about a different endorsement is offered as the "correct" answer to a question that is actually about Combination Vehicles.
Test-day logistics matter too. Bring photo ID, your Social Security card or birth certificate, your medical examiner's certificate (DOT card), and proof of state residency if you haven't already submitted those documents. The New Mexico Motor Vehicle Division will not let you sit for the knowledge exam without your documentation, and most offices charge an additional fee for re-attempts. Arrive early — the wait at most CDL testing offices runs 30 to 60 minutes — and silence your phone before the exam begins.
Finally, keep your General Knowledge fundamentals sharp even when you're focused on the Combination Vehicles exam. Many states administer multiple knowledge tests in a single sitting, and questions on weight definitions (GVWR, GCWR, GAWR), stopping distance, and the pre-trip inspection routine show up across endorsements. If you're unsure on the basics, sit a fresh New Mexico General Knowledge practice test before scheduling the real exam.
Next steps
Missed more than four questions? Re-read the Combination Vehicles study guide and the matching chapter in the official New Mexico CDL handbook. Then come back and re-take the test. Once you can score 22 of 25 or higher on three runs in a row, you're in good shape to schedule the real exam at your local New Mexico Motor Vehicle Division office.
Already comfortable with this endorsement? Drill another: NM General Knowledge · NM Air Brakes · NM Hazardous Materials · NM Passenger · NM School Bus · NM Tank Vehicle · NM Doubles / Triples
New to the CDL process in New Mexico? Read How to apply for a CDL in New Mexico for the document checklist and step-by-step timeline.