Automatic tire infla tion systems can save tire mai

ntenance costs and improve fuel economy by nearly 1%, saving 100 ga llon s of fu el an d eli minati ng one metric ton of green house

gas e missi

ons pe r year. Properly

inflated ti

res also wear longer and have fewer punctures.


## What is t he chall enge? When not properly

inflated, tires flexmore under load, produci n g heat and inc reasing rolli ng resistance, which wastes fuel. Truck tires inflated ten pounds per squ are inch (psi) below recommended air pressu re levels

can reduce truck fu el economy from 0. 5 p ercent to one p ercent. Heat and stress from improper inflation soften an d deflect tire co mponents,
c ausing faster a nd moreuneven wear, whic h shortens the life of thetire. Under i nflated tires have
more frequ ent pu ncture s, inc reasi ng the r isk of ti re failures that could l ead to costly road service a nd loss of revenue.
Despi te these costs, a recent surve y of combinati on truc ks found that less than half the ti res surveyed
werewithin five percent of the reco mmended inflation pressure. Flee ts may

find i t difficu lt to keep tires properly inflated sin ce truck tires can lose up to 2 psi each month, even if the rim seal an d valve stems a re ti g ht. This i s beca use ai r mole cules can p ermeate thro ugh tires. Temperature a n d load alsoaffect ti re pressure. For th ese re asons, t ir e manufa cturers recommend checking tire pre ssure each w eek and establ ishi ng a ti re mai ntenan ce pro gram.

Even a good tire m ainte nanceprogram may fal l sho rt of its aims. In part, this is bec ause tr ailer tir es have
more impact

on truck fuel economy than tractor tires, yet trail ers areinter

changea ble a nd thu s hard er to monito r. Since the b ulk of the load i s carried in the tra iler, a 10-psi u nder inflation in a trail er tire ma y have nearly twice the impact on truck fuel econom y as the same amount of under inflation in a driv

e tire. Despi te theimp ort ance o f keepi ng trailer tires properly inflated, a fleet may not be ableto insp ect its trail ers regula rly. A trai ler ma y be gone from th e serviceyard for

extended periods of time w hile on the road, at a c ustomer’s faci lity or at d ro p-o ff location waiting for a back haul. A fleet may not even ow n the trail ers it h aul s, bu t pi ck them up from a shippe r or third party. These c ircumstances can place much of the resp onsib ilit

y for ch ecking t ire pr essureonto drivers. However, one industry survey i ndicates only eightpercent of truck

drivers ch ecktire p ressur e wi th a tiregauge before eac h trip

. 

## What is t he solut ion? Au tomatic tire i nflati on (ATI) syste ms moni tor a n d continuallyadjust the level of pressurize d air in ti res, maintaining proper tire i nflation automati cally, e ven while the truck is moving. One A TI system uses the vehicle’s ow n ai r-br

ake compressor

to supply air to all the tires . Anoth er system us es sel f-conta in ed compres sors mounted on each hu b that are pow ered by the ro llin g moti on o f the whe els . Once an ATI system is installed, it should n ot require any special attenti on from th e driv

er.


## Th e re su lts a re in

. . . ATI syste ms c an extend tire life by eight percent o r more. The systems el iminat e the n eed tocheck t ire pressu re manually , saving time a nd la bor while
e nsuring con sistent and p roper tire in flation. Install ing
an ATI system on a truck’s driv e axlesand traile r costsup to$900, but can save over $200 annually in tire maintenance costs. For a t ypical long-haul combination truck , annual f uel savi ng s could reac h 100 gallons, sav ing $170 in fuel costs and eliminati ng one m etr ic ton of greenhous e gas emission s. The costof installing an ATI system in a line-haul truck is generally reco uped in j ust over two yea rs th rough fuel and maintena nce cost sav ings. Truck fleets may realize additiona l savin gs f r om reducing the ri sk of expensiv e tire failure caused by under inflatio n.



## Next st eps Line-haul carri ers that find it too dif ficult or expensive t o monitor tire pressure on a reg ular basis should consider ins tall ing auto matic tire press ure inflation syste ms on drive and trailer tires. ATIs can be readily retrofitted ontoexistin g trucks and trail ers. Interested fleetscan ch eck wi th ATI manufacturers and tru ck and tire d ealer

s for moreinformation. Fle ets may als o con tacttire manufacturers or their state or n ation a l trucking associatio ns for more information a bout the benefits of proper ti re inflation.