Falken Azens RT-615K+ vs Firestone Firehawk Indy 500 tires

If you were to go back 40 years ago and take a look at the kind of tires that were available for performance cars and muscle cars, you’d see a big difference in what you’d find then vs the kind of performance tires that are around now. The truth is, performance tires back then weren’t a whole lot different from ordinary all-season or Grand Touring radials when it came to design, construction, features and engineering.

That’s all changed, though, with the latest generation of performance tires like the Falken Azenis RT-615K+ and Firestone Firehawk Indy 500. With H (130 mph) and W (168 mph) speed ratings and tread patterns, rubber formulations and internal construction that are made for full-throttle performance, the Falken and the Firestone are both excellent choices for sports sedans, muscle cars and sports cars.

As we make our way through this head-to-head matchup of the Falken Azenis RT-615K+ and the Firestone Firehawk Indy 500, you’ll see us make frequent reference to the SimpleScore rankings for these tires. If you’re not familiar with SimpleScore, that’s the proprietary system that the SimpleTire team developed to assign a numerical score for the categories of traction, handling and longevity for any given tire, as well as the overall average SimpleScore. We look at specs, user reviews and other data points and then distill those into a 1-10 number value, giving you a handy at-a-glance idea of what a tire is all about. For the Falken and the Firestone, the SimpleScore ratings break down this way:

Firestone Firehawk Indy 500

• Traction: 8.5
• Handling: 8.7
• Longevity: 7.6
• Overall average SimpleScore: 8.2

Falken Azenis RT-615K+

• Traction: 8.5
• Handling: 8.8
• Longevity: 7.2
• Overall average SimpleScore: 8.1

Of course, as convenient as SimpleScore is for a quick summation of a tire’s performance, it’s also a 30,000 foot view that leaves out a lot of the important details. So to break this information down farther and do some actual compare-and-contrast work, let’s go in for a closer look:

Falken Azenis RT-615K+ tires

The Azenis RT-615K+ is an update of the competition-proven RT-615, and incorporates several enhancements. Falken designed the Azenis RT-615K+ with a soft, sticky tread formulation that’s designed to stick to the pavement like glue for unbeatable grip on the track or the street. Internal construction details of the Azenis RT-615K+ include a polyester casing with high-tensile steel belt package and a nylon reinforcement cap ply. That ensures that the Azenis RT-615K+ has the rigidity across its tread face to resist the deformation and tread squirm that goes along with fighting the inertia of hard cornering.

The Azenis RT-615K+ is designed with an asymmetric tread pattern that features zigzag grooves toward the center, a solid center rib that ensures constant contact with the road and massive sport side shoulder blocks that deliver excellent lateral traction for cornering. The notches toward the shoulder and zigzag grooves also help channel water away from the Falken’s contact patch for excellent resistance to hydroplaning on wet pavement.

NOTE: the Falken Azenis RT-615K+ is designed for warmer weather – its competition tread formulation will stiffen up and lose traction in colder weather. Falken advises that this tire can also experience cracking along the tread and sidewall in colder temperatures, which would also negate the tire’s warranty. The Falken Azenis RT-615K+ shouldn’t be used if temperatures are below 40-45 degrees F.

Firestone Firehawk Indy 500 tires

While they’re both race-bred tires that benefit a great deal from their manufacturers’ experience in motorsports, there are a few key differences between the Firestone Firehawk Indy 500 and the Falken Azenis RT-615K+. The silica-rich tread compound of the Firehawk Indy 500 is designed for excellent wet-weather traction, with tests showing braking distances that are as much as 20% shorter than the competition on wet pavement (which we’ll touch on a bit later).

The wide shoulder blocks of the Firehawk Indy 500 are designed to improve cornering and steering response on dry pavement. The center circumferential groove incorporates Firestone’s Pulse Groove Technology for enhanced water evacuation and resistance to hydroplaning, along with two additional circumferential grooves. Internal construction details of the Firehawk Indy 500 include a high-turnup polyester casing (2 ply for some tire sizes) with high-tensile steel belt package and spiral-wound nylon reinforcement layer. Like the Falken, the tread formulation of the Firestone is designed only for warmer weather; these tires shouldn’t be used if temperatures are below 40-45 degrees F.

Falken Azenis RT-615K+ vs Firestone Firehawk Indy 500 tires on traction

With identical SimpleScore ratings of 8.5 in the traction category, the Falken and the Firestone are obviously pretty closely matched. It’s also pretty obvious that both tires have some limitations, since they’re definitely not all-season tires and aren’t suitable for colder weather. The Firestone and the Falken are both tires that are designed around the torque, weight, horsepower, braking, handling and overall driving dynamics of powerful sports sedans and sports cars. That means that if you want to get a little wheelspin on dry pavement or drift your way around turns, both tires can deliver in a controllable and secure sort of fashion. Grip on dry or wet pavement is consistent and predictable with both tires, so our call is:

ADVANTAGE: Tie

Falken Azenis RT-615K+ vs Firestone Firehawk Indy 500 tires on handling

This one’s another pretty tough call, since the Falken comes in with a SimpleScore of 8.8 vs 8.7 for the Firestone. Both tires are sharp, crisp and responsive when it comes to handling and cornering, owing largely to their reinforced shoulder design, asymmetric tread pattern and reinforced, rigid construction that reduces tread squirm and deformation.

Real-world reviews, though, mention that the cornering ability of the Firestone can be a little slack, with a tendency toward understeer. Those kinds of handling properties can be the result of a sidewall that’s a little squishier and less rigid, despite the Firestone’s high-turnup casing construction. Both tires are very capable, but our nod goes to:

ADVANTAGE: Falken Azenis RT-615K+

Falken Azenis RT-615K+ vs Firestone Firehawk Indy 500 tires on longevity

Before we go any further talking about longevity, we need to point out that neither the Firestone or the Falken come from the factory with a manufacturer’s treadwear warranty. That’s not uncommon on summer-only performance tires; these aren’t the kind of tires that most drivers would pick for long trips in the family minivan or daily-driver duties picking up the kids and running to the store.

SimpleScores in the longevity category are 7.6 for the Firestone and 7.2 for the Falken. The Firestone has the distinct edge here, thanks to the proprietary Long Link Carbon tread compound that’s similar to what’s found on other Firestone products. Our call

ADVANTAGE: Firestone Firehawk Indy 500

When to use each

We should probably start off by saying when not to use these tires. Both the Firestone and the Falken are DOT approved for street use, but they’re not suitable for daily-driver duties or year-round performance. The Falken and the Firestone are specialized tires for the street or the track, and are designed for high-powered, high-performance vehicles. If you’re looking for a tire that you can use year-round or that has a quiet, comfortable Grand Touring ride quality, these aren’t going to do it for you. If, on the other hand, you’ve got a high-performance model (think Dodge Charger, Chevrolet Camaro, Porsche 911, Audi A6) and you really want to get the most out of its handling properties on twisty roads or slaloms or gymkhanas and time trials on the track, then we can wholeheartedly recommend either the Falken Azenis RT-615K+ or the Firestone Firehawk Indy 500.

Which one should you choose?

These are both performance tires that can let you carve up the onramps and twisty mountain roads as well as turning in record times at the track. Either the Falken or the Firestone would be a great pairing with a fire-breathing sports sedan, but after looking over the specs, the data points, the reviews and the SimpleScore numbers, it’s our opinion that the Firestone is the superior tire, if only marginally so. So if we had that kind of car and were looking for that kind of confident, all-out, full-blown performance, we’d probably click on the Firestone Firehawk Indy 500 over the Falken Azenis RT-615K.

Still not sure which tire to buy? Fortunately, SimpleTire is here to help as our helpful agents are more than happy to assist you in selecting the right tire for your ride and budget.