Do You Know What's Good For Your Truck and What's Not?

Manufacturers engineer vehicles with their standard features only. The braking system, transmission, suspension, axles and so on are all calibrated to handle only a small variance in the size and weight of the tire-and-wheel assembly. Opting for large wheels can throw this balance out of whack and cause vibrations or decrease these systems' effectiveness.

A truck's bed is designed to create a separated bubble, which is a bubble of air within the bed that deflects faster-moving air up and over the tailgate. Lowering the tailgate eliminates this bubble, thus creating aerodynamic drag and reducing fuel economy.

The octane rating is nothing more than the fuel's ability to resist preignition in the combustion chamber, which can result in engine knocking. Generally, manufacturers engineer mainstream pickup trucks to run on regular or mid-grade gasoline -- you can find this recommendation on the fuel cap and in the owner's manual. Running higher-octane fuel will not enhance performance or efficiency.

Truck manufacturers must consider safe driving conditions when towing, which is why they issue payload and towing capacities. Exceeding these weights can overload the braking system, suspension or chassis, causing failure or unsafe on-road operation.

Tire pressures are calculated based on the vehicle and its specifications. Failure to inflate the tires to the exact specifications listed on the tire-information placard in the door frame cause a rough ride, poor fuel economy, uneven tire wear or even a blowout.

Tires play a big role in the overall payload and towing capacities of your truck. Changing to P-rated tires, which are only rated to haul passengers, can significantly decrease these capabilities. LT-rated tires also generally have deeper tread to better handle off-road driving.

There is a common misconception that you cannot switch between synthetic and conventional oil, but this is nothing more than a myth. Both are from the same natural petroleum source, but synthetic oil goes through additional processing to enhance its ability to flow and lubricate. You can even mix them without issue.

There have been numerous studies on these magic fuel-economy boosters, and every test shows they either do nothing or actually decrease horsepower and fuel economy. Some tests showed up to 20 percent decreases in power and economy.

The Tow/Haul button will make small electrical changes via the truck's computer system to make it hold gears longer and stay out of its overdrive gear. This helps the engine better manage the heavy load without becoming bogged down. While this can make towing a more enjoyable experience, it has no direct impact on your vehicle's longevity.

The engine can use its own resistance to slow the vehicle down without ever touching the brakes with just a quick downshift. When it comes time to bring the truck to a full stop, slow brake pedal pulses gives the brakes a split second to cool down before applying full friction again. Cool brakes wear slower than hot brakes.

Dish soap works wonders for getting off stuck-on food and grease, but it uses abrasive qualities to clean your plates. This abrasive liquid can act as a fine sandpaper on your truck's paint over time and make it look dull. It also removes the protective wax coating you spend hours applying every few months.

As it hardens, mud turns to dirt, which has a sand-like consistency. Over time, its abrasiveness can wear down moving components or even contaminate the lubricants and greases that keep things moving freely. A comprehensive undercarriage cleaning will help avoid these issues.

Switching your truck's part-time four-wheel drive on and locking the hubs forces all four wheels to spin at the same time. On soft ground, the small variations in wheel angle and tire diameter are forgiven by the flexibility of the ground. Dry pavement does not provide this forgiveness, and even the slightest variation in tire pressure or wheel angle can cause the driveline to bind and result in major damage.

Trucks often have components cars do not, including transfer cases, serviceable differentials, grease points and more. All these items require additional maintenance a car does not need.

While the upgraded suspension may make the truck feel more stable at capacity, there are many other factors that affect towing and payload capacities. These include frame strength, tires and wheels, engine and transmission, and even the brakes. Though you may upgrade one component, your truck is only as strong as the next weakest component.

Torque is the most important powertrain number to consider when towing. This is the engine's ability to move a heavy load from a complete stop. Horsepower is great for top speed, but unless you're drag racing with a trailer, it is not nearly as important as the ability to get that load moving.

While water may work in a pinch when you're out on the trail and have nothing else, you must use the precise mixture of coolant and water the manufacturer recommends in normal operation. The coolant not only helps prevent freezing, but it also acts as a lubricant for all the moving parts within the cooling system. Each manufacturer has its own recommendations for types of coolant, so check out the owner's manual to find out the type your truck uses.

The term "tune-up" is a subjective term that has many meanings. A tune-up usually means replacing the spark plugs and ignition wires, which is a maintenance item that rarely fixes any running issues. It's best to allow a technician the opportunity to diagnose any running issues before simply requesting a tune-up.

The 3,000-mile oil-change interval is a myth pushed by the quick-lube industry. In modern pickup trucks, manufacturers recommend various intervals depending on driving conditions, the powertrain options you select and towing frequency. Sure, it will not hurt your truck if you change the oil early, but you are wasting money.

Maintenance time is the perfect moment to dig into all those wearable components to make sure they are in good condition. Though you may not notice anything different when driving, many of these components offer little or no warning before failing. The last thing you want is a belt or hose failing out on the trail or while towing a camper across the country.

While it doesn't work all the time, a gentle rocking motion and the side-to-side movement often gives the truck enough traction to pull out of the mud. Make sure you engage four-wheel drive and lock the hubs first. If this doesn't work, you may need to call a friend.

While four-wheel drive is great for getting your truck moving in snow and ice, winter tires play a big role in keeping it on the road and safe. They not only have the microgrooves and studs to help keep traction while driving -- something four-wheel drive does not help with -- they also have special construction to keep the rubber softer in chilly conditions.

Tires have a large number of variations, including size, tread patterns, traction ratings, speed ratings and even rubber compounds. Mixing up tires on the same axle (front or rear) can result in more drag or a different rotation speed between two sides of the axle. This uneven drag or rotation speed can cause long-term strain on the powertrain, chassis or tires, resulting in potential damage years down the road. Always at least match the tires on each axle.

Lug nut torque is an oft-debated topic, but there is no gray area in the science behind it. Manufacturers have precise torque ratings for the truck's lug nuts for a reason. Too tight, and you can stretch the threads, causing the wheel bolt to snap while driving. Too loose, and the lug nut could fly off, sending your wheel rolling down the highway without you.

You should rotate your tires every other oil change to help them wear as evenly as possible. While the tires are off, this is the perfect time to check out the brake-pad thickness and look for any unusual rotor wear. Do not wait for the brakes to start squealing or grinding, as this is a sign of potential damage that's already been done.

While the brake pads are the component most DIYers know how to replace, the rotors and calipers are equally important. Putting new pads on worn-out rotors or a sticking caliper can cause the new pads to wear out prematurely. These issues can also decrease braking performance.

In today's pickup truck engines, manufacturers go so far as engineering them down to the type of oil they require. Putting in the wrong oil weight will likely not cause any damage, but it can reduce fuel economy or power. Take the extra time to find out the exact weight and type of oil you need by checking the owner's manual.

Experts recommend keeping the heaviest items close to the cab. This not only prevents the heavy items from shifting forward when braking, but it also puts the load near the center point between the front and rear axles. This prevents the rear end from sagging and reducing the front wheels' contact with the road.

The heaviest items should always go in the trailer first and be as close to the trailer hitch as possible. This not only puts the load on the hitch, which prevents the trailer from uncoupling from the truck when driving, but it also keeps the heavy items from shifting and falling on you when you open the trailer.

The rubber grease reservoir should feel full, but not overflowing or seeping. If you overfill the reservoir and it seeps, wipe away the excess grease and seat the rubber reservoir back in place so dirt and debris cannot get in.

A truck that squeaks and squawks as you go over bumps and turn the wheels has serious front-end problems. These components likely have no grease in them and are rubbing themselves into oblivion. Eventually, these parts will fail completely, potentially causing you to lose control of your truck .

Spray-in bed liners bond to the truck's bed, giving it a semi-permanent lining that protects it from damage and doesn't allow water to get under it. Drop-in bed liners tend to rip and allow water to sit under them, which can cause serious rusting issues .

While wet mud isn't a big deal, dried mud can cause serious problems. Once mud dries, it takes on an abrasive consistency like concrete, and driving around with it on your truck can cause scratching and scuffing on your nice paint job. It's best to wash it off while it's still moist to prevent any issues.

While most trucks have some water-fording abilities -- the ability to travel through certain depths of standing water without causing damage -- manufacturers do not always publish these ratings. The safest bet is to always stay in water no deeper than the axles to avoid allowing water into the exhaust or onto sensitive electronic components.

Leak-stop chemicals have a well-earned bad rap of not working and causing more problems than good, but they have improved greatly over the years. Dumping a bottle of leak-stop in your radiator may fix the issue and save you big bucks, but you may also shell out cash for a bottle that does nothing for you because your leak was too severe. Regardless, they are perfectly safe to use -- just keep your expectations reasonable.