Rivian R1T & R1S Off-Road Tire Pressure: The Complete Guide

8 min read

Airing Down Is the Best Upgrade You Haven't Made

If you take your Rivian off pavement and you're still running highway pressure, you're leaving most of your capability on the table. Airing down is the single easiest thing you can do to change how an R1T or R1S handles dirt: a bigger contact patch, a softer ride, more traction, and less pounding through the whole truck. Every off-roader does it, on every kind of rig.

The only real question is how much. On a Rivian, the answer comes down to three things: the terrain you're on, how loaded the truck is, and, most of all, the tire you're running. A factory Euro-metric tire and a heavy-duty aftermarket LT are two different animals when the pressure drops. Get the tire part right and the rest falls into place.

This guide comes from people who actually wheel these trucks, including in the Bay Area Rivian Club community, not from a spec sheet.

Why a Rivian Airs Down Differently Than the Truck Next to It

Two things set a Rivian apart from most of the rigs at the trailhead: what it weighs and what it rolls on.

The weight. A Rivian R1T runs roughly 6,870 to 7,148 pounds at the curb, and the R1S sits close behind at 6,671 to 6,920. Both share a GVWR of 8,532 pounds, EPA Class 2b, the same class as a Ford F-250. That's a lot of mass on four contact patches, and it doesn't go away when you leave the pavement. More truck means more load on each tire, which is the first reason you can't just copy the pressures a lighter Jeep or Tacoma runs.

The tires. Every OEM Rivian tire is Euro-metric, not P-metric. There's no "P" on the sidewall. They all carry Load Index 116 and the ELECT and RIV markings that say they were specified for this truck. And the factory load math is tighter than people expect:

• Rear GAWR is 4,960 pounds, or 2,480 pounds per rear tire.
• Load Index 116 is rated for 2,756 pounds.
• Run that through the FMVSS de-rating factor for a multi-purpose vehicle (divide by 1.1) and you're at 2,505 pounds of usable capacity per tire.

That's a 25-pound margin. Not 25 percent, 25 pounds. Drop the pressure on that tire and its capacity drops with it, which is exactly why the factory tire can only come down so far. It's already carrying most of what it can. For the full construction story behind Load Index and de-rating, the SL vs LT tires guide covers it end to end.

Which OEM tire came on your Rivian

Every factory tire is Euro-metric, Load Index 116, marked ELECT and RIV. What changed between generations is the brand and tread. Gen 1 shipped exclusively on Pirelli; Gen 2 broadened the lineup.

One note if you wheel often: the 22-inch tires give you barely five inches of sidewall to work with, so there's very little air to give before you're risking the wheel and sidewall. The 20-inch setup has far more room to air down.

The Tire Decides How Low You Go

This is the part that matters most, and it's where a lot of online advice falls apart, because it hands you a number without asking what's mounted on your truck.

OEM Euro-metric tires air down less. Rivian says 31 PSI or higher on the OEM 20-inch setup. In the field, CJ has had good results at 28 PSI for slow trail driving and technical obstacles. Twenty PSI is not a travel pressure. It is a short move for a stuck truck, a slow extraction, or extra flotation in soft sand. Once the truck is moving, air back up before continuing.

A heavy-duty LT tire airs down more, comfortably. Swap to an E-rated LT and the story changes. An LT tire in this class carries a Load Index around 126, rated near 3,750 pounds with no de-rating penalty, on an 80 PSI (sometimes 65psi) structure. That stiffer, stronger sidewall is built to carry load at lower pressure. It's the added stiffness that lets the tire do well with less air, so on an LT swap you can settle into the low-to-mid 20s for technical terrain and stay there all day.

Same truck, same trail, two different tires, two different pressures. That isn't a rule somebody made up online. It's the construction of the tire. If you're weighing the swap, the tire upgrade calculator shows what changes in real terms.

One bit of background worth knowing: a Rivian runs a short sidewall on a big 20-inch wheel, so there's less margin to keep the bead seated once you get really low. Chasing single-digit numbers is a job for beadlock wheels, not something to improvise on the trail.

Pressure by Terrain

Start higher and work down as the ground gets softer or more technical. These are working ranges, not hard numbers, and where you land inside them depends on your tire and your load.

The OEM column stays higher because the factory tire is carrying a heavy truck. Use 28 PSI only for slow trail work. Treat 20 PSI as a temporary extraction setting, then air back up once the truck is moving. The LT column can run lower because its construction carries the load differently. Two adjustments ride on top of the table:

• Maxed out for a multi-day camping trip: add some air to your normal off-road pressures. More weight means you need more PSI in your tires for the same control and stability. An R1S with a full third row and cargo, or an R1T loaded down in the bed, is the usual way you get there.
• Back up to speed, air back up. The low-speed heat exemption is the whole reason 18 to 28 PSI survives off-road. Above about 30 mph the tire builds real heat those low numbers can't handle, so get back near highway pressure before you pick up the pace.

The PSI cheat sheet has the quick-reference version if you'd rather not do the math at the trailhead.

Highway PSI and the Range Question After an LT Swap

Two numbers that surprise new Rivian owners: the door and the pump.

The door jamb calls for 48 PSI front and rear on-road and notes 31 PSI for off-road use on the OEM 20-inch wheels. The 28 PSI field setting above is for slow trail work. Twenty PSI is only for a brief extraction or a stuck-truck sand maneuver, followed by airing back up. The compact spare, for what it's worth, wants 61 PSI.

After an LT swap, the math says an E-rated LT wants roughly 38 PSI for highway load support. In practice, most owners run higher, in the 50 to 60 PSI range, to protect range and even out tread wear. CJ runs 55 PSI on his 285/65R20 Goodyear Duratracs, slightly larger than the OEM 275/65R20. It's a trade between ride, wear, and range, and most owners settle in the mid-50s.

Which brings up the range hit, because it's bigger than the internet tells you. The commonly cited figure for a chunkier LT tire is a 3 to 7 percent range reduction. Real Rivian owner experience puts it closer to 7 to 10 percent, which is 20 to 30 miles off a roughly 300-mile rated pack. That's not a reason to skip the swap if you actually wheel the truck. It's a reason to go in with the real number.

Airing Down and Back Up on a Rivian

Airing down all four is the easy part. Airing back up a 7,000-pound truck's worth of tires is where a Rivian throws its one real curveball: amp draw.

A high-output portable compressor like the MORRflate TenSix pulls 50 to 70 amps running and around 90 amps at peak. That's more than most EV 12V systems want to hand over, so the plug-into-the-12V-socket approach that works fine on a gas truck often isn't the move on a Rivian. The common workaround is an AC compressor run off the truck's bed outlet; CJ uses a 120V AC unit that way for exactly this reason. The full compressor guide walks through matching output to this weight class.

One Rivian-specific note: to use the truck's built-in factory compressor with a MORRflate manifold (AirHub or Stubby) and hose kit, you'll need the MORRflate MFRX adapter. It's a fitting adapter for Rivian's non-standard compressor port, not a length extension, and you can skip it if you run a portable compressor. A MORRflate manifold (AirHub or Stubby) paired with a four-tire hose kit lets you air all four back up at once, which on a truck this heavy is worth the setup.

Frequently Asked Questions

How low should I air down my Rivian?

It depends on the tire. On the factory Euro-metric tires, stay in the mid-to-upper 20s for general trail use and only dip into the low 20s briefly to get through something soft, then air back up. On an E-rated LT swap, the low-to-mid 20s is a comfortable all-day working range for technical terrain. Match the pressure to the terrain, add a little when you're loaded, and air back up before you get back to speed.

Why do OEM and LT tires need different pressures?

Construction. The factory Euro-metric tire is a passenger-build tire carrying a heavy truck, so it gives up load capacity as pressure drops and can't live at low pressure. An E-rated LT has a stiffer, stronger sidewall built to carry the same load at lower pressure, so it airs down further and stays there comfortably. Same truck, different tire, different pressure.

Do I need to add air when I'm loaded for a trip?

Yes. A Rivian packed for a multi-day trip carries more weight over the tires, and more weight wants a few more PSI for the same control and stability. Bump your normal off-road pressures up a little when you're maxed out, and drop back down when you unload.

Do I really need to air back up before highway speed?

Yes, every time. Low off-road pressure is safe because you're going slow. Above about 30 mph the tire builds heat those low numbers can't handle, so air back up before you get back on the road.

Does this apply to other EVs like a Lightning or Hummer EV?

The general idea carries: heavy rig, mind your tire construction. The specific pressures don't. Curb weight, OEM tire spec, and wheel size all differ, so don't copy Rivian numbers onto a different truck.

Air down for the terrain, mind your tire, add a little when you're loaded, and air back up before the pavement. That's the whole game. Less air. More trail. See you out there.

Everything we run and why: /gear-i-use.