What Wheel Offset and Tire Size is Right For Your Ram Truck?

Wheel offset refers to how far a wheel sticks out from the hub of your truck. and we like to use offset rather than backspace to describe wheels as it's related to the width of the wheel unlike backspace. This means offset gives a more complete picture of how a wheel will sit on your truck.

To put it simply, the more positive the offset, the more flush or tucked in a wheel will sit. The more negative the offset, the wider a wheel will sit. Stock wheels are about +45 on RAM trucks for reference. 

Wheel specs have a huge role in looks, but keep in mind they also plays a critical role in tire fitment and how much trimming you need to clear a particular size tire. The bigger the tire and the less lift you have, the more important it is to have the correct specs on your wheels.

The photos above show the two different offset specs offered in the Foundation Wheels 395 HD. The grey truck on the left is running the 18x9 395 HD wheel in 0 offset, and the truck on the right is running the 18x9 395 HD wheel in +19 offset. It's also worth noting that the truck on the left is running a 13.5" wide tire, while the truck on the right is running a 12.5" wide tire. That tire width also plays a role in how wide the full package sits. 

Offset and tire width can work together to achieve the look you're after. For reference, stock wheels are about +45 offset, which makes them extremely tucked into the truck. In order to fit 35s, 37s, or 38s, you need to run a wheel that's approximately 0 offset to +27 offset, with 0 and +19 being the two sweet spot specs.

You can then use tire size to fine tune looks. For example if the +19 spec with 37/12.5s shown above looks too tucked in but the 0 with 37/13.5s looks too wide, you can use a +19 offset with a 37/13.5 or vice versa. 

Now that we have offsets figured out and you know how you want your truck to look, it's time to discuss trimming. We want to preface by saying that the following information is all in reference to trucks that have a level or 3-4" lift. If you are stock height on any Ram, we recommend nothing larger than a 35" tire unless you have a 2014+ Power Wagon or 2023+ Ram Rebel trim truck. 

You may notice that we didn't recommend and we don't offer any wheels in a negative offset. The reason for that is anything past about 0 offset on a 9" wide wheel on the Ram platform severely limits tire size as it requires trimming that just isn't acceptable for most. 

If you want a zero trimming setup, stick with a 37/12.5 on a +19 offset wheel. Like the silver truck shown in this article, that will sit nice and flush with no trimming needed.

If you are okay trimming the plastic fender liner, then you can go with a 37/13.5 tire on a +19 offset wheel or a 37/12.5 tire on a 0 offset wheel. 

If you are okay trimming the pinch weld on the cab and plastic fender liner, then you can run a 37/13.5 tire on either a 0 offset or +19 offset wheel. 

If you really want to push the limits, then you can do a 38/13.5 tire on a 0 offset wheel as shown, but you will need to trim the pinch weld, fender liner and do a tie back on the fender liner with zip ties for clearance. 

The following videos show give this information in more detail, plus who doesn't like moving pictures?

These photos show a nice side by side comparison between two trucks. The silver truck is on a 18x9 +19 offset Foundation 395 HD wheel with 37/12.5/18 Toyo AT3 tires and the Grey truck is on 18x9 0 offset Foundation 395 HD wheels with 38/13.5/18 tires. This is the difference between little to no trimming, and more involved trimming. 

Ultimately this decision comes down to the look you want to achieve and how you feel about trimming. Keep in mind we'd not talking about taking a sawzall to the fender here, but we also get that not everyone wants to trim their nice truck. 

If you want a flush fitment with the fender and no trimming, go with a +19 offset wheel and 12.5" wide tire. If you want to be a little wider and are okay trimming some fender liner plastic and maybe a little of the pinch weld, go with the 0 spec and a 12.5" wide tire. If you want the most aggressive look and you're okay trimming to make it happen then go with 0 offset and a 13.5" wide tire. 

Still lost? Don't feel bad! Shoot us an email and we'd be happy to help.