SirMouthsALot
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Vehicle: 2022 Gen 1 R1T Quad Motor - Large Pack
Tire: Cooper Discoverer AT3 XLT 275/65/R20 (LT)
I replaced my OEM Pirelli ATs with the Cooper Discoverer AT3 XLTs a couple of months ago. The Pirellis had 18,000 miles and had started to get pretty noisy. The fronts were down to 6/32 and I wanted new tires for the winter. My use case is 80% highway and 20% city streets, with the occasional trips on forest service roads and a jeep trail every once in a while. I waited until the Coopers had 3,000+ miles on them to post this. The short version: They're both better and worse than the OEM Pirellis, depending on what you're looking for.
Installation: Like many ATs, these tires do not balance well and I've got a little steering wheel shimmy at 60+ MPH. I got them road-force balanced and we couldn't get any tires below 20 lbs. One was at 50 lbs and I am working to get it replaced under warranty. Wish me luck.
Ride/Handling: I was surprised that the vehicle's ride improved over bumps, despite running the tires at 62 PSI cold. I'd say the ride is about 10-15 percent softer than the Pirellis at this pressure. At 50 PSI, the ride is even softer. However, turn-in and steering response is predictably worse - these tires are heavy and don't let you forget it. My truck now feels like a truck. It is still more capable in the corners than any other pickup, but gone is the unreal feeling of "how does this feel like a sports car" on canyon roads. At highway speeds, the increased rotational inertia is very noticeable. Initiating an abrupt lane-change is uncomfortable and can border on dangerous depending on the suspension settings. The tread squirm when the tires were new was just silly, but it has gotten much better now that they have vulcanized.
Traction: The dry traction is about equal to the OEM tires, but take this with a grain of salt as I'm only measuring this with a butt dyno. Straight-line acceleration and braking is about equal, as is lateral traction. My initial feedback on wet traction and hydroplaning is that it seems to be a little worse than the Pirellis, but I will come back and update this post in a couple weeks as the PNW cycles into the wet season and I have some more time on wet roads.
Noise: Quieter than the Pirellis, but not by much. Above 65 MPH, while these tires aren't silent, the noise blends into the background well and is unobtrusive. Between 45 and 60, however, there is some annoying tread growl on different surfaces. I am now considering putting Dynamat in my wheel wells, but that's a separate thread.
Efficiency: At 62 PSI cold, my lifetime efficiency for the Coopers is currently at 2.06 (within 4-5% of the Pirellis). This is with 90% highway driving at 70-75 MPH, at temperatures between 65-75 F.
Off-Road: Not a lot of data here, but no complaints. Handled gravel roads just fine. Did well on some moderate jeep trails with no punctures or loss of traction.
Looks: Very chunky sidewalls in person that compliment the 20" ATs nicely. I'm a fan.
Overall, I was a little disappointed with this purchase. I was hoping to get a tire that could match the OEM Pirelli ATs on wet traction and efficiency while improving noise and treadwear performance. Instead, vehicle dynamics took a significant hit, for a marginal improvement in noise and ride comfort. I'll probably keep them through the winter and move to the the OEM Goodyear tire if/when Rivian lets us change wheel/tire size ourselves.
Tire: Cooper Discoverer AT3 XLT 275/65/R20 (LT)
I replaced my OEM Pirelli ATs with the Cooper Discoverer AT3 XLTs a couple of months ago. The Pirellis had 18,000 miles and had started to get pretty noisy. The fronts were down to 6/32 and I wanted new tires for the winter. My use case is 80% highway and 20% city streets, with the occasional trips on forest service roads and a jeep trail every once in a while. I waited until the Coopers had 3,000+ miles on them to post this. The short version: They're both better and worse than the OEM Pirellis, depending on what you're looking for.
Installation: Like many ATs, these tires do not balance well and I've got a little steering wheel shimmy at 60+ MPH. I got them road-force balanced and we couldn't get any tires below 20 lbs. One was at 50 lbs and I am working to get it replaced under warranty. Wish me luck.
Ride/Handling: I was surprised that the vehicle's ride improved over bumps, despite running the tires at 62 PSI cold. I'd say the ride is about 10-15 percent softer than the Pirellis at this pressure. At 50 PSI, the ride is even softer. However, turn-in and steering response is predictably worse - these tires are heavy and don't let you forget it. My truck now feels like a truck. It is still more capable in the corners than any other pickup, but gone is the unreal feeling of "how does this feel like a sports car" on canyon roads. At highway speeds, the increased rotational inertia is very noticeable. Initiating an abrupt lane-change is uncomfortable and can border on dangerous depending on the suspension settings. The tread squirm when the tires were new was just silly, but it has gotten much better now that they have vulcanized.
Traction: The dry traction is about equal to the OEM tires, but take this with a grain of salt as I'm only measuring this with a butt dyno. Straight-line acceleration and braking is about equal, as is lateral traction. My initial feedback on wet traction and hydroplaning is that it seems to be a little worse than the Pirellis, but I will come back and update this post in a couple weeks as the PNW cycles into the wet season and I have some more time on wet roads.
Noise: Quieter than the Pirellis, but not by much. Above 65 MPH, while these tires aren't silent, the noise blends into the background well and is unobtrusive. Between 45 and 60, however, there is some annoying tread growl on different surfaces. I am now considering putting Dynamat in my wheel wells, but that's a separate thread.
Efficiency: At 62 PSI cold, my lifetime efficiency for the Coopers is currently at 2.06 (within 4-5% of the Pirellis). This is with 90% highway driving at 70-75 MPH, at temperatures between 65-75 F.
Off-Road: Not a lot of data here, but no complaints. Handled gravel roads just fine. Did well on some moderate jeep trails with no punctures or loss of traction.
Looks: Very chunky sidewalls in person that compliment the 20" ATs nicely. I'm a fan.
Overall, I was a little disappointed with this purchase. I was hoping to get a tire that could match the OEM Pirelli ATs on wet traction and efficiency while improving noise and treadwear performance. Instead, vehicle dynamics took a significant hit, for a marginal improvement in noise and ride comfort. I'll probably keep them through the winter and move to the the OEM Goodyear tire if/when Rivian lets us change wheel/tire size ourselves.
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