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Tires are generally a dull subject for limousine operators until one goes flat or blows out during a fleet run. Then, you start paying attention. Here’s a guide to running the right tires so they don’t become too interesting of a topic.
A Significant Investment
The average price of a quality tire for a limousine or sedan runs between $120 and $165 each. Every vehicle in your fleet may go through several sets of tires in the life of the vehicle. Tires should be replaced with quality versions that have a proper rating capacity for the load to be carried as well as the right kind of tire for highway traveling. Operators who experience snow in the winter may need to have two complete sets of tires to provide service during the winter months. Tire replacement on minicoaches and buses are a big expense. You need to know how to select and maintain the proper tires for your vehicles.
Budgeting & Saving
For the small- to medium-size operator, a complete tire replacement could easily become a financial burden if you don’t plan and budget for it. An easy way to budget for tires is to calculate the complete cost of tire replacement on a particular vehicle and divide that amount by the life expectancy of the tire. For example, if a tire is expected to last 60,000 miles and the tire costs $150, then it costs .0025 per mile to operate. If you put 1,500 miles on your vehicle in a month, the operating cost is $3.75 for the month. It would take you 40 months to wear the tires out if you average 1,500 miles per month. Considering you have four tires on most vehicles, your total operational cost for tires is $15. That is the amount you should set aside each month into a tire replacement fund for each vehicle.
Modern Tire Dealer Bob Ulrich says independent dealers will offer a much wider variety of tire brands and models.
When buying new tires, you will always have most of the money. Bob Ulrich, an editor with Modern Tire Dealer magazine, recommends you compare a 40,000 mile tire for $X.XX vs. an 80,000 mile tire for $X.XX and do the math because it might be cheaper to buy the tire with the shorter life span if it costs less to run per mile. (See chart on how to determine per mile cost).
When To Replace
Although you may expect 80,000 miles, many factors contribute to tire wear, such as road temperature, driving patterns, tire inflation, load factors and road condition. Nothing lasts forever. Monthly tread inspections can reveal the need for replacement. In most states, tires are legally worn out when their tread depth reaches 1/16 inch (or 2/32 inch as found on standardized tread-depth gauges).
While the old penny stuck upside down is probably your grandfather’s method, Consumer Reports Magazine says for a better indicator of tread wear, place a quarter upside down in a tire groove. The distance from the coin’s rim to George Washington’s hairline is about 1/8 inch. If you see all of his head in any one groove where a tread-wear indicator appears, consider shopping for new tires.
To start shopping, obtain the numbers of the tire from your sidewall.
What The Numbers Mean
For the lay person, all the numbers on the side of a tire can be confusing. We’ll break it down for you in this chart:
Understanding Tire Codes
Example P215/65R 15 95H M+S
P........... Passenger Car
215.........Width in millimeters from inside to outside edge
65...........Aspect ratio of height to width
15...........The diameter in inches of the wheel intended to fit
95...........Load Index is 1,521 lbs. or 6,084 lbs on four tires*
H..............Speed rating is 130 MPH**
M+S.........Mud and Snow
*Source: www.discounttire.com/dtcs/infoLoadIndex.dos **Source: www.tirerack.com
The recommended size of the tire can be found in the glove box, doorjamb or fuel filler door on most vehicles. However, vehicles converted may require a larger tire to accommodate additional weight. Ask your coachbuilder to confirm the placard on the car is accurate.
Size is expressed in the number, P235/70R16 95 H. The “P” denotes the tire is intended for a passenger car. With most limo buses and large vans, you would buy a tire designated LT for Light Truck. The number 235 is the width in millimeters, while 70 is the ratio of sidewall height to cross-section width (70%). R means radial-ply construction and 16 is the wheel diameter in inches.