• Rivian’s second-gen R1S and R1T have a new pedal box design incompatible with first-gen all-weather floor mats.
  • The Rivian-sold mats for the Gen 1 can cause the Gen 2’s accelerator to get stuck, leading to unintended acceleration.
  • The automaker is likely developing new all-weather mats for the second-gen vehicles.

Rivian’s updated R1S and R1T have a host of new features that add to what many customers already love. At the same time, several of the changes are somewhat subtle and one of them is the pedal box. One customer found that out the hard way after installing rubber floor mats meant only for the first-gen R1 vehicles.

The mats in question are the “All Weather” mats sold by Rivian directly. They come as a set of four mats including one for each of the front seats and then one for each of the subsequent rows. Notably, Rivian points out online that they’re “Compatible with Gen1 vehicles only.”

Read: VW Throws Rivian A $5 Billion Lifeline, But Can They Stay Afloat?

According to one member of RivianForums, that’s because the accelerator can become stuck on the mat in the second-gen R1 series.

“We quickly got on the highway after delivery and… well… I floored the accelerator… as one does with a very powerful vehicle,” they wrote on of the forum. “The accelerator got stuck behind the mat and the car quickly accelerated unintentionally,” they say.

The member went as far as to photograph and explain the issue as well. “The Gen2 has a small bump on the floor right in front of the accelerator. The mat was correctly installed but it’s not of the right size for the Gen2. The carpet mat is smaller to avoid the bump on the floor,” they continued.

Photos ChapULine/Rivianforums

Pictures show just how different the stock carpeted mat is from the rubber one.

They’re different by several inches and it’s easy to see why the pedal might get stuck. It’s likely that Rivian is in the process of creating a second-gen R1 all-weather mat. What’s unclear at this point is what exactly changed in the pedal box that ended the chance of all-weather-mat cross-compatibility.

We’ve reached out to Rivian for comment on that and will update this piece if we hear back.

 Rivian R1 Gen 2 Owners Warned Against Using Gen 1 Floormats Or Risk Stuck Accelerator
The second-gen 2025 Rivian R1S