Tire Size Guidance for SmartWay Verification
The following explains tire sizes and load ranges for new tire verification testing and why specific sizes may be indicated on the verified list.
When testing rolling resistance for SmartWay verification, test tire sizes 295/75R22.5 or 275/80R22.5 and load range G can qualify additional tire sizes and load ratings. If a manufacturer tests either of these options, the verified list will not specify a tire size, and the scope of verification covers the model tire in each of the sizes and load ranges in "Table 1. Common Heavy-duty Tractor-Trailer Tire Sizes and Load Ranges."
Table 1. Common Heavy-duty Tractor-Trailer Tire Sizes and Load Ranges
| Tire Size | Load Range |
|---|---|
| 295/75R22.5 | G |
| 295/75R22.5 | H |
| 275/80R22.5 | G |
| 275/80R22.5 | H |
| 11R22.5 | G |
| 11R22.5 | H |
| 285/75R24.5 | G |
| 285/75R24.5 | H |
| 275/80R24.5 | G |
| 275/80R24.5 | H |
| 11R24.5 | G |
| 11R24.5 | H |
If a manufacturer tests a size other than 295/75R22.5 or 275/80R22.5, and load range G, the verification scope is limited to the size tested. In these cases, the tire model is listed with a size and load range restriction, and verification is only for the specific size(s) and load range(s) indicated.
Tire manufacturers may also have specific tire designs for certain tractor or trailer features such as the drive axle or tag axle on 6x2 tractors. To accommodate these technologies, EPA may also include additional descriptions on the verified list. Some additional tire sizes and load ratings, other than those shown in Table 1 above, may also be verified for tractor-trailer applications such as drop deck trailers or car carriers. In these cases, the tire size will be specified. Please consult with your tire manufacturer regarding the best fuel saving tires for your tractor-trailer needs.
Tire models listed with a limited scope or restrictions are verified only for application(s) indicated. Table 2 illustrates examples of different verification scope, and explanations are provided below.
Table 2. Examples of Tire Verification Scope
| Brand Name | Technology Type | Axle Position | Tire Model(s) |
|---|---|---|---|
| XYZ | Tire | Steer | STE, SDD |
| XYZ | Tire | Drive | SDD, ABC (tag on 6X2 size 255/70R22.5 load range H only) |
| XYZ | Tire | Trailer | ABC, ABC (size 255/70R22.5 load range H only) |
For the steer axle position, the tire models STE and SDD are each verified for the sizes and load ratings in Table 1 above.
For the drive axle position, the SDD tire is also verified for each of the sizes and load ratings in Table 1. The ABC tire model is only verified for the tag axle and tire size 255/70R22.5 load range H. In this case, manufacturer XYZ may have specified use on the tag axle.
For the trailer axle position, ABC tire model is verified for all tire sizes and load ratings in Table 1 above, and it is also approved for size 255/70R22.5 load range H.