When it’s time to select the best tire make/model as well as retreads that work best for your fleet, there are many questions which need to be answered.
Every fleet is faced with different issues when making this determination based upon their specific operation. Most fleets have vehicles which run under various service vocations, which of course will require specific tires depending on wheel position.
Let’s address the various considerations:
· Initial tire buying price
· Retreadability of the tire casing
· Fuel economy
· Removal miles
· Susceptibility to developing irregular and uneven wear
· Tire traction
It is only logical that a low purchase price would make the choice easy for a fleet manager and their finance person. However, fleets should understand their full cost of ownership in terms of total cost/mile including retreads; and that the purchase price is only part of the cost equation. Historically, even though all tires are black and round, they are not created equal. Tread depth, compounds, steel wire gauge and tread design will significantly affect fuel economy, mileage, traction and retreadability.
The lowest priced tire may only achieve one retread per casing compared to the higher priced tires which will get two or three retreads. Fleet fuel economy could be improved as much as 3% with the more expensive tire designs. Tracking cost/mile over multiple retreads takes some serious effort. It is not simple. The cost calculation should include the initial purchase price, cost of each retread, casing credit, scrap disposal fees, mounting & dismounting charges, tire repair charges and any rebates offered from your tire suppliers.
Tracking miles of the original casing and each retread also becomes challenging. Branding every tire with a unique tire identification number is essential to this process. It is a lot for a fleet to record odometers when a tire is installed or comes out of service. If a tire is repaired and then reapplied on another wheel position, a new set of complexities enter the equation. Unless a trailer is equipped with a hubometer or an ABS that tracks mileage, determining mileages of trailer tires is almost impossible.
Many fleets simply estimate trailer tire miles based on the installation and take-off dates. Tracking vehicle fuel economy is always very difficult. 95% of the time, tractors are NOT married to trailers. With many fleets running a 3:1 trailer-to-tractor ratio and various tractor models/specifications, the results become complicated.
In addition, a misaligned trailer will have a serious negative impact on vehicle fuel economy. Underinflated tires will play a major role in vehicle fuel economy as well as the specific tire make/ model that’s chosen and its tread depth, design and compounds. Some tires are less susceptible to developing irregular wear. When tires develop irregular wear conditions such as shoulder cupping, heel/toe wear and depressed ribs, they will be bouncing as they roll down the highway. The result is fuel economy drops and tire removal miles are dramatically reduced.Tire traction can be an issue when tires are worn close to the minimum DOT limits of 4/32” for steer and 2/32” for drive and trailer tires. Traction is always the best with new rubber. The fleet manager must
take these variables into consideration when making the ultimate decision on what is the best overall tire combination to be running in their fleet. It is always recommended to work with your local tire professional in making tire decision choices.
Q&A PSI ANSWERS YOUR QUESTIONS
Q. What should my drivers be checking in their morning walk around when it comes to tires?
A. Checking tire pressures with a calibrated tire gauge (not a baseball bat), looking for any sidewall cuts/tears, identifying tires with irregular wear and inspecting tread for punctures are all important.