Know-how
Most trips end early for a reason that was visible in the driveway. This is what to look at, and what the numbers on your own door mean.
Preparing a vehicle is not a shopping list. It is an inspection, an arithmetic problem and a shakedown, and the three of them together prevent most of what strands people.
Every figure here comes from the National Highway Traffic Safety Administration or from the federal standards that put the labels on your vehicle. Where a figure is specific to your vehicle, this guide tells you where to read it rather than inventing one.
Underinflation is, in NHTSA's words, the leading cause of tire failure, and the correct pressure is not written on the tire. It is on the Tire and Loading Information label on the driver's door edge or pillar, and in the owner's manual. The number moulded into the sidewall is the maximum the tire can hold, not what your vehicle wants.
Check every tire including the spare at least once a month and before a long trip, cold, meaning the vehicle has stood at least three hours. A tire pressure monitoring system is not a substitute: NHTSA points out that it only warns when a tire is significantly underinflated, by which time you have been driving on it.
Then look at them properly. Tread should be at least 2/32 of an inch; the built-in wear indicators tell you when it is not, and so does a penny with Lincoln's head upside down. Check both sidewalls for cuts, cracks, bulges, scrapes and punctures. Uneven wear across the tread means rotation or alignment is due.
Age matters even when tread does not. You cannot see tire ageing, and some vehicle and tire makers recommend replacement at six to ten years regardless of wear. The last four digits of the DOT code on the sidewall give the week and year it was made. Look on both sides, because the code may be on only one. And check the spare: NHTSA notes spares are especially prone to ageing because they seldom get replaced.
Do not skipA spare that has never been checked is the commonest bad surprise on a remote road. Read its pressure, its age and its condition before the trip, not on the day you need it.
Two federal labels carry everything you need. The certification label, on the driver's door pillar or door edge, gives the Gross Vehicle Weight Rating and a Gross Axle Weight Rating for each axle. The tire and loading placard on the B-pillar gives the combined weight of occupants and cargo you must never exceed, the seating capacity, the recommended cold tire pressures and the tire size.
The definitions are worth knowing exactly. GVWR is "the value specified by the manufacturer as the loaded weight of a single vehicle". A GAWR is the load-carrying capacity of one axle, measured at the tire-ground interface. And the standard requires the GVWR to be at least the unloaded weight, plus the rated cargo load, plus 150 pounds for every designated seating position.
The arithmetic the federal rule puts in every owner's manual is the one to do before a trip: read the combined occupant and cargo figure on the placard, subtract the weight of the people who will ride, and what is left is your available capacity for cargo and luggage. If you will tow, some of the trailer's load transfers to the vehicle and comes out of the same number.
Nobody guesses their loaded weight correctly, and the difference between opinion and fact is a public scale. Oregon's Department of Transportation notes that its scale decks are operational around the clock for public use, and that a private or public scale will usually provide a certified weight receipt for a fee. It even lists "just started operating and want to ensure they don't overload their vehicles" as a reason the public uses them.
Weigh the vehicle loaded the way it will actually travel: water full, fuel full, people in it. If you can, weigh each axle, because a build that is within GVWR can still be over its rear axle rating, which is where the drama lives.
What to do if you are over is not complicated, only unwelcome: take things out. Overloading affects handling, stopping and tires, which is why the federal rule requires owner's manuals to say so.
NHTSA publishes essentially the same list for summer and winter trips, and it takes half an hour.
System by system
NHTSA's own kit list for a road trip is a sound base: a phone and charger, a first aid kit including a tourniquet, a flashlight, flares and a white flag, jumper cables, a tire pressure gauge, a jack and a ground mat, work gloves and a change of clothes, basic tools and duct tape, water and paper towels, non-perishable food, medicines, extra washer fluid, maps, and emergency blankets.
For winter it adds a shovel, a broom and an ice scraper, an abrasive such as sand or cat litter, and blankets. Keep the fuel tank close to full whenever possible, which matters more the further you are from a pump.
Our recovery and trail repair guides cover the overland additions: traction boards, a proper shovel, rated recovery points, a tire plug kit and a compressor, and the spares that fit your vehicle.
Vibration is what a washboard road does to a build, and it finds every fastener nobody torqued. At the end of the first day on dirt, walk round with a torch: rack bolts, skid plates, drawer and fridge mounts, battery hold-downs, spare tire carrier, anything you or a shop fitted recently.
Look underneath as well. Check that nothing is hanging, that no wire has rubbed through against a bracket, and that no fluid is where it should not be. Five minutes then is worth an evening later.
The last step of preparation is a night out close to home, with the vehicle loaded exactly as it will travel and the meal cooked on the stove you will use. Nothing else finds the forgotten adaptor, the drawer that will not open with the fridge in place, or the bed that is two inches too short.
Then fix what the night showed before the real trip. A shakedown you do not act on is just a night out.
Anything on the brakes, the steering, the suspension or the charging system that you are not confident in belongs with a mechanic before a long trip, not after. Overland mechanics, 4x4 shops, tire shops and suspension specialists in the directory do this work, and a pre-trip inspection is a normal thing to book.
Ask for two things in writing: what they found, and what they recommend doing next. Then you are choosing, rather than hoping.
On the Tire and Loading Information label on the driver's door edge or B-pillar, and in the owner's manual. NHTSA is explicit that the correct pressure is the vehicle maker's figure, not the number moulded into the tire, which is the maximum the tire can hold.
When the tread reaches 2/32 of an inch, when there is damage or irregular wear, or on age: some vehicle and tire makers recommend replacement at six to ten years regardless of tread. The last four digits of the DOT code give the week and year of manufacture.
Gross Vehicle Weight Rating: the loaded weight of the vehicle specified by its manufacturer. The federal standard requires it to be at least the unloaded weight plus the rated cargo load plus 150 pounds for each designated seating position. Each axle also has its own rating.
Read the placard line that says the combined weight of occupants and cargo should never exceed a given figure, subtract the weight of the people riding, and the rest is your cargo capacity. Towing takes some of that too.
At a public scale, including state highway scales in some states, or at a truck stop that has one. A private or public scale will usually give a certified weight receipt for a fee. Weigh it loaded as it will travel, and by axle if you can.
Reviewed September 19, 2026. Conditions, closures and rules change; check with the managing agency before you travel.