Tips on checking tire pressure

Tips for checking truck tire pressure

tires-wheels-column

Every tire manufacturer is constantly preaching the importance of maintaining proper tire inflation when it comes to maximizing tire treadwear, increasing casing retreadability, improving fuel economy and lowering cost per mile. Visibly inspecting tires and checking tire pressures are recommended on a regular basis. “Regular” for some fleets may mean every day, once a week or monthly; for others, it might mean only during a PM. Application also plays a role. Fleets that see off-road service and pickup and delivery city service, for example, should be checking tire pressures most frequently.

Recommended tire pressure is based on the worst-case load the tire will see under real world conditions. Once you know that load, a load/inflation table will advise what is the recommended cold tire inflation pressure.

Cold inflation is based on room temperature of 68° F and do not include any inflation pressure build-up due to vehicle operation. Never adjust tire pressure based checking a hot tire just coming off the highway. A hot tire may see an increase of up to 15% from the cold inflation pressure. It can take several hours for a tire to cool back down and reach ambient pressure.

During the pre-trip inspection process, tires should be at the top of the list for drivers. Some drivers use their boot to kick the tires to check for proper pressure, others use a baseball bat and a few drivers use a stick or a dial pressure gauge. During the major trucking trade shows and exhibitions, some of the tire companies and retread associations will have multiple inflated tires on display with a contest for truckers to identify the tire pressures from low to high based on using the old reliable baseball bat. In reality, the only information the baseball bat will tell the driver is if the tire is completely flat. It is only by pure luck that a trucker will identify the correct tire pressures using a baseball bat.

Looking for more insight on tires and wheels? Click here to read through Al Cohn’s archive of columns.

Regardless of manufacturer, a stick tire pressure gauge is only accurate to plus or minus (+/-) 3 PSI brand new out of the box. This means that a tire with 100 actual PSI could measure 97 PSI with Gauge A and 103 PSI with Gauge B. Dropping a stick gauge from steering wheel height onto the hard concrete surface can cause the plastic piece with the PSI numbers to regress to +/- 5 PSI with only one drop. Stick gauges need to be verified for accuracy with a master gauge on a frequent basis. If the gauge is inaccurate, it is time to toss it. Some gauges are adjustable by turning the set screw at the bottom of the stick gauge.

Checking with technicians in a shop with 10 stick gauges, you will see quite a range of pressure readings unless they are calibrating their gauges with a master gauge or air gauge checking station (see below).

Why are stick gauges so inaccurate?

When you look inside a passenger or truck tire stick gauge it is all the same: A plastic or metal stick with numbers and a spring are the two major components. The spring stiffness coefficient varies from gauge to gauge leading to a large variation in results. Depending on how the plastic stick lines up inside the spring during manufacture will also play a large role in the final measured PSI value.

Dial gauges are a step up from the stick gauge. There is still a wide range of results from the various type of dial gauges available in the market, and they are typically not adjustable. There is also a significant price increase associated with these dial gauges. When purchasing a dial gauge, check with the manufacturer to determine the accuracy. If there is no mention of accuracy on the gauge packaging, then it may be wise to simply purchase a stick gauge.

Accuracy of dial gauges are available in four grades: A, B, C and D. Grade A is the best with an accuracy of +/- 1 % in the middle half of the scale. Grade B is +/- 2 %, Grade C is +/- 3% and Grade D drops to +/- 5%.

Maintaining proper tire inflation continues to be the secret to reducing costs and optimizing your tire program.

You May Also Like

United Natural Foods to deploy eCascadia and VNR Electric trucks

UNFI will combine these trucks with refrigerated trailers cooled by Carrier’s all-electric Vector eCool TRU.

United-Natural-Foods-1400

United Natural Foods, Inc. announced that it is deploying two battery-electric trucks and five regenerative electric refrigerated trailer systems. UNFI is deploying the trucks and trailers in the Sacramento and Gilroy, California markets, just in time for the peak holiday selling season.

UNFI worked with Penske Truck Leasing to secure two Class 8 electric trucks: a Freightliner eCascadia and a Volvo VNR Electric. UNFI will combine these trucks with refrigerated trailers cooled by Carrier’s all-electric Vector eCool transport refrigeration unit (TRU).

Freightliner M2, SD Plus Series launch updates its medium-duty truck offering

Freightliner introduced the new Plus Series–enhanced versions of its M2 and SD models, including the M2 106 Plus, M2 112 Plus, 108SD Plus, and 114SD Plus. The enhanced models provide a major update to the interior and electrical systems of the M2 and SD models. The OEM noted that the Plus Series is designed to

Freightliner-MD-SD-Plus-Series-1400
Truck cruise control technology that looks at the road ahead

If you’ve ever visited the Northeast region of the country, you’ve most likely encountered intimidating terrain. The winding roads. The steep hills. The intricate routes that challenge any seasoned driver, and, most recently, advanced cruise control systems that aim to improve fuel efficiency and driver comfort.   Related Articles – Four ways A.I. can help cut

Four ways A.I. can help cut diesel fuel costs

The fluctuation of fuel prices has made it more challenging to operate day-to-day. Drivers get paid by the mile, and, when fuel costs go up, margins shrink, impacting how fleets profit and pay their employees. Intelligent technology can lessen the impact of high prices by improving overall fuel efficiency. Related Articles – New ways to

AI-trucking-generic-1400
Peterbilt GM Jason Skoog charts today’s truck support, tomorrow’s truck solutions

Peterbilt made headlines recently when it became the first major North American OEM to open orders for an electric truck, the Peterbilt 220EV. In this exclusive interview, Peterbilt General Manager and PACCAR Vice President Jason Skoog details the technology investments that are keeping fleets productive during this year’s trying pandemic and laying the groundwork for

Peterbilt General Manager PACCAR Technology Electric Truck

Other Posts

Daimler Truck delivers Freightliner eCascadias to Reyes Coca-Cola Bottling

The 20 Freightliner eCascadias are expected to result in the reduced use of 40,000 gallons of diesel fuel per year. 

Daimler-Trucks-Coke
Nicholas Trucking on cutting costs and emissions

Early success with propane-powered trucks has the fleet planning to replace more diesel trucks.

nicholas-propane-truck2-1400
Kenworth ADAS adds new features for T680

Adaptive Cruise Control Stop and Auto Go and Highway Departure Braking to Zero features are now available.

Kenworth-Donates-T680
Truck driving safety requires attention

It’s hard to focus on safety when you’re focused on shifting. Episode two of the Fuel Efficiency Faceoff shows why.

EPS-2-faceoff2-1400