wide-base tires: pros & cons
Recently, more employers have begun using wide-base tires (sometimes referred to as “super singles”, which is actually a trademarked name of Goodyear Tire & Rubber Co.) on their trailers instead of conventional duals. So what are the predominate advantages and disadvantages?
- Weight savings: Duals add up to 1,300 lbs over depending on whether you are replacing both the drive and trailer tires and whether you are using them with aluminum wheels in place of steel. This may allow extra payload in the trailer.
- Fuel economy: Reduced rolling resistance of one wheel versus two (10-15% less contact area). By most estimations, the fuel economy increases from 1% to 4%.
- Environmental: Related to the above, since tire rolling resistance accounts for nearly 10% to 15% of truck energy use (the Federal EPA averages 13%), this means less energy use (fuel), and with thousands (or millions) of trucks out there on the roads, a greener industry.
- Improved, softer ride: Less side-shimmy because the tire is so wide the vehicle is not susceptible to the normal road rutting or water drain grooving on the road surfaces. This means better control in these instances.
- Maintenance: again- one tire verses two to mount.
- Dual tire/wheel matching: Eliminates these concerns.
- Improved brake cooling: An obvious safety issue.
- Road Contact: A safety issue. Contrary to popular belief, wide base tires do not provide more road surface contact than duel standard tire configurations. A conventional trailer tire size is 11R22.5 and the most common wide base tire size is 445/50R22.5. One 445/50R22.5 is NOT double two 11R22.5 tires. So using (2) 11R22.5 tires gives an overall tire footprint of 124 sq inches. Using one 445/50R22.5 has a footprint of 111 sq inches (10% less contact area).
- Higher sensitivity to overload: Due to the reduced tire-surface contact area, the wide base tire is doing more “work” than two duals. Any under-inflation would be a more critical issue.
- Heat: Again, if not properly inflated, would generate more heat. Running even 10% under inflation will lead to premature tire removal because of irregular wear and tire durability issues.
- Traction: Due to the shortened lateral contact length of the wide base verses the double tire configuration, there may be less traction due to the physics of a lengthened lateral ‘lever’.
- Wear pattern: More sensitive to wear. Under-inflated wide-base tires will lead to fast centerline wear and overinflation will result in fast shoulder wear.
- No limp-home capability: Although not recommended to limp “home”, obviously limping out of danger is a major advantage. Duals offer this ability.
- Weight: Wide based are obviously individually heavier, adding a burden to maintenance staff (and increasing the possibility of injury and maybe requiring assistance from another maintenance technician).
So, to go “wide-base” or not? As wide-base tire quality and technology improve, we will see more use simply because the advantages (though perhaps fewer in number) are greater. “Green” advantages (decreased energy use) are too important to our earth not to use them. The question may be more an issue of “when” rather than “if”.