If you’ve ever looked at a tire size before, you’ve probably seen a letter at the end that has nothing to do with the tire’s actual size. That letter corresponds to the tire’s “speed rating,” which is the maximum speed that a tire can safely reach and maintain without falling apart.
These speed ratings are required on road tires in the United States, as they give consumers a clear idea of just how fast they can travel while maintaining trust in the tires not to suddenly give out at triple-digit speeds. Each letter represents the maximum speed the tire is good for. For example, if a tire has a “J” speed rating, it can go up to 62 mph safely. A “P” rating means the tire can go up to 93 mph.
For the most part, as you go down the alphabet, the speed rating gets greater. There are some exceptions, though. Here’s the full chart, courtesy of Discount Tire:
Note how the “H” rating is way farther down than it should be, and V, W, and Y are all higher than Z. These changes were made to accommodate the evolving performance arena, catering to vehicles with higher capabilities. From Discount Tire:
While most tire speed ratings increase in max speed the further along the alphabet they are, there are a few notable exceptions to this rule. In this system, tires with a Z rating would be the fastest rated tires out there. At one time, Z-rated tires were thought to be the highest rated tires a vehicle would need.
But the development of faster vehicles brought us two new speed ratings: W and Y-rated tires, both of which are rated for higher speeds than the Z despite their earlier place in the alphabet. These speed ratings provide a more precise indicator of a high-performance tire’s speed over 149MPH.
H is the only other speed rating that doesn’t appear in alphabetical order. A holdover from the early European speed rating system, the tire experts of the time chose not to change the original rating indicated by H.
From the factory, passenger vehicles must have tires that can handle their top speeds. Otherwise, manufacturers would be putting customers in a dangerous situation right off the bat. Ram is recalling a bunch of 2500 models built between 2022 and 2026 over “speed calibrations” that can exceed the factory tire speed rating.
According to Ram, the 2500 has a top speed of 105 mph. The 2500 gets a tire with an “R” speed rating, which means the rubber is good for 106 mph. From the sounds of it, Ram seems to have inadvertently set the top speed for the affected trucks higher than 106 mph, which is where the problem arises.
Thankfully, the issue didn’t rear its head due to a crash or injury—it came up during an internal Stellantis review back in March, which flagged the potential dilemma. A total of 12,736 trucks built between June 2022 and April 2026 are affected.
Instead of replacing the tires with higher-rated rubber, Ram is going to reflash affected trucks’ ECUs to lower the top speed to be within acceptable levels for the existing tires. For the vast majority of 2500 owners, they won’t notice any difference. But if you’re one of the few truckers maxing out their 3/4-ton pickup on country back roads, then you might run into a speed limiter where there wasn’t one before.
This is one of those cases where you might not want the recall done. Who wants a lower top speed put on their truck? If I had one of these 2500s, I’d equip a tire with a higher speed rating instead. This solves the problem and allows me to keep my higher top speed. I can already see the Facebook Marketplace listings. “For Sale: 2024 Ram 2500 In Good Condition—NO RECALL DONE, HIGHER TOP SPEED!!!”
Sadly, some states, like my home state of New York, won’t renew registrations if your car has an open recall. So I’d be out of luck. But if you’re in a part of the country that doesn’t really care whether you have recalls done or not, congrats! Your truck has a higher top speed than advertised. And so long as you keep it away from a Ram dealer, no one should be able to take that away from you.
Top graphic image: Ram
“Instead of replacing the tires with higher-rated rubber, Ram is going to reflash affected trucks’ ECUs to lower the top speed to be within acceptable levels for the existing tires”
I suspect that this is one of the safety updates most owners won’t care about and skip.
Now having said that, even 105mph is way faster than any truck like this should be going.
Also… no love for an X tire speed rating? Given how so many trim levels and vehicle model names rely on ‘X’, you’d think the industry would LOVE to have an X-Rated tire…
I’m noticing that tire rating chart conveniently skips over X. Apparently, there are no “X-Rated” tires, which I’m sure is a source of endless frustration for RAM owners.
This reeks of auditors gonna audit.
Reflash the RAMs, a few mph slower isn’t gonna get Jim-Bob away from the Arkansas State Police. They PIT up to 130 anyways.
Hi have you met your average Ram owner? “Back roads” lets be real, they’re doing that in the right lane on I-95.
This is relevant to trailer tires. So many of the cheap ones are J (62 mph) rated. Like, why are those even allowed for sale?!? Yeah, someone probably has a small trailer pulled by a quad that won’t go past 40 or so. That said, a small trailer going down the freeway at 75 mph hopefully has M (81 mph) rated tires. Or a camper. At least buying M rated tires is some assurance the tire isn’t a China bomb.
Yeah and that is not something they tell you when you buy the trailer or replacement tires. I am honnestly more surprised that I don’t see more trailers on the side of the road with failed tires. It isn’t that uncommon for me to be doing 75 mph in the middle lane while some guy towing his boat/travel trailer/work trailer blows past me.
Turns out this is an issue with every truck manufacturer, but only RAM had to do a recall because of their clientele.
They don’t want a blowout when they’re tailgating a car that’s already going 30 over.
I’m kind of frightened to ask, but what would the stopping distance on a crew cab, well optioned 2500 4×4 going 105? 600 feet not including reaction time?
Assuming the tires hold the road, they should have pretty good stopping distance. The brakes are rated for both towing and max payload. So Billy BadAss in the left lane with his vanity truck COULD stop fast. The question is if he will.
“Sadly, some states, like my home state of New York, won’t renew registrations if your car has an open recall.”
What do people do when there’s a recall but parts aren’t available? I had a car in 2019 with an open recall on the Takata airbag, but parts weren’t available to fix it.
Buddy of mine LS-swapped his Geo Metro and had to search long and hard for 13″ Y-rated tires. The entire exterior remained stock as he wanted this to be true sleeper build.
When I owned a Metro I dreamed of doing something like this, but of course I never did. How did he get the LS in there? Did he modify the suspension and brakes, etc. to handle the power?
Why is the rear tire so narrow in the top shot? It almost looks like one of those compact temporary spares; made me think that the issue was that owners were driving far too fast on their spare tires.
Picture smells like AI…
It smells like the front tire was copied, sliced, and stretched to fit the rear aspect better. (I’ve done similar just to get curriculum out the door on tight timelines. Macaroni & Fuck it)
I agree – same flame pattern. Just a quick chop shop photoshop, no need to ring the AI alarm.
Well, no offense to Brian, but it looks very half-assed either way.
The header image with the flaming tires made me think that if they remade Krull and set it in the modern world, the characters would be riding Fire Rams. Just some random thought. Maybe because I think Krull is ripe for a re-make but I’m sure Hollywood would still cock it up.
Did you tell NY that? I have a co-worker who still hasn’t done his Auto-Park recall on his Ram 1500 and he has renewed his registration a couple times since the recall came out, AFAIK.
So what’s the top speed when there is no letter after the tire size?
Walking speed.
Whatever speed they end up blowing out at, that speed minus 5mph is rating.
Feel free to test and get back to us.
Same principle as the bridge load limit rating, as explained by Calvin’s dad.
Most young males figure out their load limit once they hit puberty.
I know the exact strip you are referencing. Bravo.
To infinity and beyond!
Everything just sounds so dire these days.
This is probably more common than we think on trucks that offer a variety of tire diameters and rear end ratios. A set RPM for fuel cutoff corresponds to quite a variety of actual road speeds even with the same engine and transmission.
The fact that it’s only 12,000 trucks over a four year period; a tiny fraction of the number built, makes me believe the issue is limited to one optional tire size + rear end ratio combination.
The speed limiter is not a rev limiter, it is based on the VSS signal. So as it leaves the factory the computer should know the actual tire size and gear ratio it is equipped with so that the speedo actually reads correctly. Sure once it is out the door someone may change the tire size or gear ratio and not do the proper adjustments in the code to correct that.
This might set the standard for stupidest recall ever.
Also, why bother having a speed limiter in a 3/4 ton truck if you set it to 105 mph? I don’t think many owners would care/notice if you set the limit to 90. If your company’s lawyers are strict/irritating enough to make you issue a recall because they can go 107 and their tires are rated for 106, you may as well give yourself more margin of error.
The speed limiters have always been there because of the tire ratings.
Unless you drive something like a Chevy Aveo, whose top speed is “aerodynamically limited”.
The Chevy Sonic is also aerodynamically limited to roughly 124 MPH.
Yeah, I know it is due to tire ratings.
I’m just saying if you are going to do a speed limiter on a vehicle that is the polar opposite of a sports car, why set it to 105 when you could set it to 90? It is fine if your tire’s maximum speed is 30 mph above your limited speed.
Ask Firestone who gets the blame when it comes to tire failures.
I mean, you’re not wrong and I’m not necessarily arguing with you.
I just can’t understand why they don’t engineer themselves a bit more margin of error. I doubt any customers would choose a competitor’s truck solely because their trucks are limited to 90 instead of 106.
Just set the speed limiter well below the tire’s rated limit. Literally no buyers are going to care.
If they set the limit lower, the bean counters will probably just make them buy lower rated tires that are cheaper.
Fair point.
It just seems so stupid, though, that the bean counters and lawyers make this difficult for no reason.
But if nothing else, isn’t this stupid recall going to cost them some money? It seems like the bean counters are short sighted.
Can confirm.
I worked for Thrifty Rent-A-Car in the late 1990s. We had Chrysler 300Ms.
We got different trims of this car; some with 17″ wheels, and a luxury variant with 18″.
The 18″ cars had a limited top speed of ~127 mph. The cars with 17″ wheels had V-rated rubber for some reason and were good for 140+.
I was 18 and stupid, OK?
If I was an affected owner, this would piss me off in theory, more because I’d need to decide between buying tires with a higher speed rating and dodging a recall for the rest of the time I owned the truck, or just doing the recall and accepting the limit.
Pretty sure I never exceeded 80 in the last truck I owned, but still . . . It’s the principle of it.
Aren’t all trucks already limited to a speed well under what it would actually be capable of going based on gearing and power?
My F250 is limited to 95 mph which in 10th gear can’t be much more than 2,000 rpm (I have no idea – I’m not sure I have ever gone over 80 even briefly). With 475 hp/1050 torques I presume my truck has more than enough power to overcome wind resistance well above the factory 95 mph limit.
If Ford sent me a recall notice saying it needed to lower the limit to 105, I’d throw away that recall notice even faster than I’ve thrown away the previous twenty or so I have received.
It’s disturbing that some states don’t do the basic due diligence to ensure that recalls are complete.
I’ve often found it difficult to get a vehicle in for a recall in a timely fashion.
One on my wife’s Dodge a few years back took almost 2 years to resolve, not through lack of effort on our part.
I don’t blame states for not wanting to track that mess.
Many states don’t even do safety inspections so you could be doing 110 down the freeway in your massive truck with the cords showing through on your tires and it wouldn’t be an issue with the registration.
Yikes, theses are speeds people should not be even close to doing on public roads in 3/4 ton trucks (or any thing else for that matter).
I wouldn’t be sure they “inadvertently” set the top speed to higher than 105. You have to account for tolerance in the speed sensors, tire inflation, yada yada yada. If the tire can handle 105 you should probably set your top speed to 100 or even lower.
Who is going that fast in a 2500 anyway?
The majority of Florida.
Last time I was in Florida, traffic was ridiculously slow everywhere. More like island time than a Grand Prix.
Granted I was a ways away from the Freedom Factory . . .
So true. I had my cruise control set at 79 and people on I-95 south of Jacksonville and along the Space Coast were blowing past me like I was standing still. 99 is fine, 100 means pain.
Waaaaaaaaaaaaaaaayyyy too many YA males.
Driving into work this morning a lifted bro-dozer with a goofy ass giant exhaust tip facing straight down stop at a red lot of an intersection I was driving through (I had the green) and he was going to be turning the same way I was going. I had the thought watch the lifted dude bro will catch up to me when I already go 5-10 over (it is a 55mph highway so I set my cc normally that much over and cruise in the right lane). And wouldn’t you know it a few miles down the road he flys past me going 80+. Was hard to tell in the dark but was either a dodge or fjord 250/2500 (possibly 350/3500)
This sounds like it rates as important as floor mats in a Toyota.
Yo dawg, I heard you like floormats in your Toyota, so I stacked a dozen floormats in your driver’s side footwell for you.