Typically, fuel economy and maximum mileage are prime considerations when purchasing rubber. But when it comes to spec'ing for city fleets another set of criteria applies to ensure you get the best re...
Typically, fuel economy and maximum mileage are prime considerations when purchasing rubber. But when it comes to spec’ing for city fleets another set of criteria applies to ensure you get the best return for your tire dollar.
Consideration should be given to the type of work the vehicle is doing. A power unit delivering to construction sites might need more traction and a stronger casing than one doing P&D work. A truck transporting produce will probably see more highway miles and be subject to less scruffing than one banging around back alleys.
It’s also worth mentioning that most of Canada is snow country (unless you’re running Vancouver to California). During the winter months, a drive tire with an open shoulder design and blocks on the shoulder and throughout the tread pattern can provide more aggressive traction in rain, mud and snow.
Urban trucks operate in a completely different environment from those running up and down the highway. They’re constantly turning, reversing and rubbing against curbs. Heavy haulers like cement mixers work around rebar and rubble, while sanitation vehicles crawl along back alleys and wade through debris-strewn lots.
For the above reasons, tires intended for city work are constructed differently from those meant for linehaul or even regional use. The tread depth is deeper and extends further across the shoulder. The sidewall ribs are reinforced, and the rubber compounds used in the manufacturing process are stronger and more durable.
Urban tires wear out quicker than linehaul models and that’s mostly the result of repetitive turning. According to Al Cohn, technical director of the Goodyear Tire and Rubber Co., tires in urban applications get about 12,000 kms per 1/32″ of tread wear, as compared to approximately 29,000 kms per 1/32″ for linehaul use.
“Grocery fleets, soft drink vehicles, and pick up and delivery trucks tend to scrub their treads off,” says Cohn. “You’ve got to consider your worst case scenario, and then make the decision. Fleets think they’re the experts, but the secret of success is to work with your tire professional.”
There’s probably no solid way to know how a tire will respond to your specific operating conditions without testing it in the field. But since city trucks come home every night it should be easy to keep track of how many kilometers you’re getting per 1/32″ of rubber simply by measuring the tread depth every couple of months.
Selecting the perfect tire for your application might come down to a trade-off between tread patterns. Steering tire or trailer tires, for instance, have ribs that run circumferentially around the tire that can be either fairly straight or zigzagged. The straighter grooves are more fuel efficient and better for linehaul, while the zigzag pattern bites better on wet city streets.
“It’s probably a good solid business decision to run five trucks with one kind of tire and five with a different set. By vehicle number you can tell how the tires are doing,” says Cohn.
Goodyear, like the other large manufacturers offers a wide variety of profiles and models available for most trucking vocations. Cohn suggests G149 RSA might work well on a city tractor’s steering axle. For the drive tandems he recommends either G167 or G164 RTD.
“The GI67 gets excellent traction while the G164 gets better mileage without compromising much on traction,” he says.
Derek Varley, fleet manager of Mackie Moving Systems in Oshawa, Ont., runs Bridgestones and Michelins on hundreds of power units and trailers. His fleet is equipped for two applications – linehaul and regional. Regional, in this case, includes P&D, pup trailers and four-axle trailers.
“There’s a lot more scrubbing on the tires, especially on the four-axle trailers with nine foot spreads. Only the first two axles lift and that forward axle just drags. You need stronger sidewalls and that sort of thing,” he explains.
So instead of Bridgestone R195 linehaul tires on the steers and trailers, Varley goes with R250 regional tires on his pups, B-trains and lift axles.
Brian Rennie , director of sales engineering for Bridgestone Firestone Canada thinks you could have a situation where a vehicle is subjected to both linehaul and city conditions in the same shift, when a lot of twisting and turning occurs at both ends of the run.
“In some cases, our R260 regional steer tire could prove to be more economical than a linehaul tire,” he says.
“The R260 actually incorporates an equalizer rib that prevents the spread of irregular wear, and this gives it somewhat broader range capability than the R250,” adds Rennie.
According to Ralph Beaveridge, marketing manager for Michelin Canada, a reputable tire dealer can also be a great help in spec’ing traction tires. “It’s important to establish a customer’s needs,” he says. What size vehicle, what type of load, how many times an hour do you stop, how many times do you turn? How important is traction vs. mileage? If you can cut 1% in fuel savings, that’s huge savings for a fleet.”
Beaveridge suggests the XDS drive tire with its roust on-off road casing might be perfect for an urban heavy vehicle like a dump truck, but less economical for a fleet specializing in LTL and city P&D.
“For those carriers delivering to the Costcos and Wal-Marts, the XDE M/S drive tire is designed to be a versatile drive tire with an open shoulder that gets excellent mileage and traction,” he says.
For a multi-position tire, Beaveridge likes Michelin’s XZE, a type of hybrid that is at home on the steering axle or any trailer position.
Not to be outdone, Yokohama also supplies a full line of regional and urban tires in 19.5, 22.5 and 24.5 wheel sizes. According to Greg Cressman, Yokohama technical services director, “generally these are hardier tires with stronger sidewalls with less delicate tread patterns that resist cutting and stone drilling (when a tire picks up a stone that works its way down to the base rubber and causes a puncture).”
Cressman is particularly enthusiastic about the RY617 steering tire that bridges the zone between long haul and regional work. ‘It’s basically a premium product that’s snuck in as a core product,” he says.
Retreading is certainly something to look at when buying new skins. Truck owners can save 50% by retreading their used casings, according to Harvey Brodsky, managing director of the Tire Retread Information Bureau.
“If you tried to sell a single life tire to a large fleet they would just laugh at you,” says Brodsky. “All the tires made by reputable manufacturers are designed for multiple lives.”
Literally hundreds of tread patterns are available for retreaded tires specific to urban trucking. Again, it’s important to work with your tire dealer to assure your tires have multiple and hassle-free lifetimes.
“The quicker you wear out a tire, the more times you can retread it,” says Greg Filer of Bandag Canada.
New tire shoppers should also consider the durability of the casing, he says.
And this goes for light duty trucks as well. “Manufacturers like Michelin and Bridgestone are finally building tires for 16″ and 19″ wheels that are fully retreadable,” adds Filer.
Regardless of what tire you buy, a good tire maintenance program is essential to economical tire life. Choosing the right tire might be the second most important part of your program – maintaining the correct inflation level is probably the first, according to most tire experts.
“I can’t stress the importance of a good tire maintenance program enough,” says Filer. “If fleets carry out a good air-up and tire rotation program they can definitely save money.”
Harry Rudolfs writes about motor carrier issues from both a hands-on and analytical perspective. An award winning journalist, he combines years of experience in the motor carrier industry with a writing background which includes work for the Ottawa Citizen, Toronto Life and CBC Radio.