Round 1: Testing Enduro Tires
Our tire tests tend to prize that single fastest lap: Which model can lay down the best time at an autocross or time trial event? We do give a nod to performance consistency, but that’s usually with 20 minutes of track time and good weather conditions in mind. Don’t expect those test winners to still be delivering after a few dozen laps–or in the wet or the cold.
But with the rise of budget-friendly enduro competitions sanctioned by the likes of Lemons, ChampCar and WRL, demand has grown for a whole new set of tire requirements. Those races last anywhere from 7 to 24 hours, making durable and consistent tires the key to a top finish–or finishing at all. And with multiple teammates pulling driving duty for each car, those tires need to be intuitable and communicative at the limit, too.
To keep costs down, many endurance race series now mandate street rubber with a minimum UTQG treadwear of 200. Options in this category are plentiful, since the rule overlaps nicely with requirements in various other “street tire” motorsports–think SCCA autocrosses and time trials, Optima Search for the Ultimate Street Car, and Tire Rack One Lap of America Presented by Grassroots Motorsports.
In endurance racing, the favorites have been the Hankook Ventus R-S4 and Maxxis Victra VR-1. Enter the newcomer: the Valino Pergea 08R. Time to test how these hold up for the long haul.
The Tires
From left to right: Top Dog Hankook Ventus R-S4, Top Dog Maxxis Victra VR-1, New Challenger Valino Pergea 08R
Test Car
For a test of this nature, we needed a vehicle that could easily deliver many consistent laps. The answer? Miata, of course. Specifically, we used our forthcoming ND2 project, which we’re currently prepping for SCCA Time Trial’s Sport 5 class.
Flyin’ Miata lowering springs allow for aggressive camber settings of 3 degrees all around, effectively using all of the tire’s tread surface. Karcepts anti-roll bars front and rear keep the balance neutral and promote even tire wear at both ends of the car. Pagid track pads from the Global MX-5 Cup cars provide consistent stopping power without overheating. (Note: The Karcepts bars are not rules-compliant and will be replaced soon with legal bars from Good-Win Racing.)
We normally time trial on 17×9-inch 6UL wheels from 949 Racing wrapped in 245/40R17 Bridgestone RE-71R tires. Since the only common size for our three test subjects is 225/45R17, we rounded up a few extra sets of the stock 17×7-inch BBS wheels and headed to our friends at Automotive Specialists for mounting.
Test Method
All of the tires were scrubbed and subjected to a single gentle heat cycle at the track plus an hour of highway driving. Then we gave them at least 24 hours of rest.
We measured outright pace through our usual process: cycling through each tire for five hard laps at Harris Hill Raceway in San Marcos, Texas, a place where we’ve racked up a lot of laps. This same-day test was bracketed in an A-B-C-A fashion to verify driver and condition consistency.
Once relative time trial pace was established, we sampled each tire’s endurance capabilities by running it for a solid hour at 10/10ths. Given the mental focus required, these tests were done on different days, meaning there was some variance in temperature and track condition.
We got a great read on consistency of feel and performance over the long haul. Resultant wear patterns and depth then gave us clues about how durable a tire would be in a full-length race.
The Results
Hankook Ventus R-S4
Go to a budget enduro grid and you’ll typically find more than half the field on this tire. It offers the gold-standard combination of long life, consistently strong performance, and intuitive communication. As such, we ran it both first and last to bracket our time trial testing.
FAST LAPS:
With ambient temps in the upper 60s, the Hankook took more than just the single lap to fully come up to temp. Our AiM Solo 2 datalogger showed our laps opening with a 1:30.1 and dipping to low-1:29s halfway in. After those laps, performance dropped off a bit and stabilized in the mid-1:29s.
Our bracketing round at the end of the morning netted a bit more speed, most likely due to track clean-up and driver improvement. Lap 3 was best at 1:28.4 before dropping off a half-second again. Interestingly, the logger showed the first two passes had only a single small bobble compared to the “perfect” flyer.
ENDURANCE LAPS:
Endurance testing the next morning produced a similar pattern of lap times. The first pass was a little slower at 1:29.3, with the next three on pace in the mid-1:28s and a 1:28.2 flyer on Lap 4. After that, times dropped a few tenths and settled in the high-1:28s through low-1:29s.
Lap after lap, our times nestled into a tight half-second spread. Notably, a bit of performance was regained near the end of the stint as fuel levels dropped and the tires wore to lower tread depths. Average times went back into the mid-1:28s, with a final 1:28.3 flyer at the 1-hour mark.
The R-S4 offers a very typical performance tire driving profile: linear response, strong grip and small slip angles. Breakaway is progressive, allowing for easy recovery from small mistakes.
Maxxis Victra VR-1
When Maxxis first introduced the VR-1 four years ago, it was aimed squarely at the track day and enduro market. Contingency programs were posted, and some very specific motorsports sizes were produced. In particular, they were first to market with a 245/40R15 street tire, pleasing Miata owners everywhere.
But some owners reported that pressing the VR-1 hard at full tread caused chunking problems. The factory responded 18 months ago, when it introduced its new tire built with the improved S2 rubber compound. We’ve been itching to test these, especially after we heard that the new, stronger compound also provided more grip. Win-win.
FAST LAPS: The Maxxis offered super-responsive performance. It dove down to apexes much more easily than the Hankook. It also required very little warmup, netting its best lap time on the very first circuit–and matching the Hankook’s single best. As the Maxxis heated up, though, response dropped off, the tire got a little mushy, and lap times slowed a bit.
The AiM datalogger showed most of the deficit coming in Turn 7, a heavy multitasking section of the track where threshold braking blends into off-camber, decreasing-radius cornering followed by an important power-down zone off the corner. Left-side tires take a real beating here, and ours were likely overheating when pressed. We lost additional time in sweeping Turn 8, where the right-side tires are fully loaded for a long time.
ENDURANCE LAPS: A few days later, we spent an hour on these tires at maximum attack. The quickest laps again came early, with a 1:29.5 and 1:29.2 opening up the session. As heat built up and tire response fell off, times soon fell into consistent high-1:29s and low-to mid-1:30s.
Compared to the Hankook session, we had more difficultly putting together consistently quick laps on the Maxxis. Recovery from taking the tire over the limit was harsh: Not only did we pay an immediate price for the over-ask, but subsequent turns were also affected. Still, we sprinkled a few 1:29.6s throughout the session when all the stars aligned.
Valino Pergea 08R
A host of low-production performance tires are coming from Asia. Many are marketed at the drifting segment, but some are also useful for road course and autocross. Some are 200 treadwear, while others are R-comps. They typically cost less than the bigger names, but finding them can be a challenge as traditional retailers don’t carry them.
One such tire brand is Valino, and the Pergea 08R is its Extreme Performance Summer tire model. Valino’s American distributor was anxious to get a set in our test, believing the tire’s drifting heritage would translate well to road courses and especially enduros–and give us a taste of their forthcoming true track tire.
The first thing we noticed while inspecting the Valino was the soft compound. And while we aren’t ones to put too much stock in absolute durometer readings, we stuck each tire with the tool to quantify that relative difference. The Valino measured out the softest of the three at 58; the Hankook was two points harder and the Maxxis another two points harder still at 62.
We also measured the tires as they came off the track and found the same two-point delta between each, but the Valino was now at 51. And while softness doesn’t always mean strong grip, it does certainly affect how the tire handles–especially when the Valinos start with 10/32 inch of tread while the other two start at 9/32.
FAST LAPS: The Valino had a unique combination of driving characteristics. We weren’t formally testing road manners, but the Valino wandered the most on the way to the track and required constant steering attention.
Once on the circuit, it offered a delayed response to driving inputs, while slip angle built up before the tire began cornering. This necessitated much earlier turn-in and a bit of guesswork. The front and rear of the car also felt quite disconnected.
But grip was superb. Once we established significant slip angle, the tire would hang on for a good long time no matter how hard we pushed it. These attributes are great for drifting but a challenge for consistency on a road course.
Like the Maxxis, this tire required no warmup and delivered its best lap (1:30.05) on the very first pass. As heat built up, though, the Valino just got slower and slower. By Lap 5, we were circulating 2 seconds off our original pace and stuck in the 1:32s. The datalogger revealed that we lost time steadily throughout the lap.
ENDURANCE LAPS: Our enduro session delivered similar results. Lap times were quickest out of the box but eventually settled a couple seconds slower. By mid-session, lap times began to rebound.
The Valino became more predictable as the tread wore down and tread squirm became less of a factor. In fact, a post-test look at the left-front tire showed extensive wear and an uneven wedged pattern typical of a soft compound on a deep-treaded tire.
Bottom Line
It’s clear why so many put their faith in the Hankook R-S4. It’s a legit street tire that checks all the boxes for track use, delivering strong, consistent performance that’s easy to extract. Its only downside is a recurring backorder status for popular sizes early in the season. It’s also the priciest of the bunch at $150 in our test size.
The Maxxis VR-1 is also a great choice. It’s a little slower and less consistent than the R-S4 while also wearing a little more quickly, but availability has been good for its limited range of sizes. It’s less expensive than the Hankook at $128 each in our test size.
As for the Valino, while it‘s fun to drive on–the car tries to drift at every turn–it’s not in the same league as the other two. It fell to the bottom of the charts in all three metrics: outright pace, consistency and wear. But, at $124 each in our size, it’s the least expensive tire in this test. It wasn’t the fastest, but we’ll give it high marks for fun as we welcome another player to our world.
Round 2: Testing Autocross Tires
Tire companies are constantly raising the bar, developing new models in an arms race of rubber compounds and tread patterns. But back in 2014, the SCCA hit the reset button: Instead of allowing Stock-class autocross competitors to run R-compound tires that were barely street-legal and had the half-life of a gnat, a new rule required “real” street tires sporting a treadwear rating of 200 or higher.
The trade-off motivated companies to keep it simple, but two of them settled into most-favored-nation status: Bridgestone was first to today’s top step with its Potenza RE-71R, but BFGoodrich followed soon after with the g-Force Rival S. These tires offer similar performance, but each has unique characteristics and is offered in sizes that draw favor from different camps.
In 2018, Yokohama quietly superseded its track-focused Advan A048 with the A052. Treadwear increased from 60 to 200, but its limited sizing and shallow tread depth made it ineligible for those SCCA autocross classes requiring a 200-treadwear rating.
By machining its molds a little deeper and building a portfolio of additional sizes, Yokohama now offers a legal tire for this segment: the 2019 version of the A052. And unlike its competitors, it can fit rim diameters as small as 14 inches.
Tire Rack moved the model from its Streetable Track & Competition category to Extreme Performance Summer, which makes it compliant for other street tire-oriented competitions. In fact, Yokohama debuted the new tire on a pair of Subarus at this year’s One Lap of America. Fielding the cars: Nitro Circus stars Travis Pastrana and Blake “Bilko” Williams.
Time to test that Yokohama against the two class stalwarts. Will it upset the apple cart by pushing performance to new levels? Or will it quietly become a third choice for characteristics and sizes? Time to assemble the team, start the clocks, and dodge some cones for science.
The Tires
From left to right: New Challenger Yokohama Advan A052, Top Dog Bridgestone Potenza RE-71R, Top Dog BFGoodrich g-Force Rival S 1.5
Test Car
Street Touring R 2019 Mazda Miata
Test Method
Piloting the Miata for our experiment were multi-time national champions David Whitener (its owner) and Andy Hollis. Our venue was the permanent “Dial-In” test course we painted down at the Mineral Wells airport more than a decade ago. Thousands of laps have been turned on its concrete surface over the years, mostly by us.
The layout features a five-cone slalom opposite three offset gates, bookended by two sweepers–one on-camber and the other off-camber. A single run consisted of two laps following a rolling start into the downhill sweeper. We also used the site’s flat skidpad to establish optimal tire pressures and evaluate steady-state grip.
All tires were size 255/40R17 and mounted on 17×9-inch 6UL wheels made by 949 Racing. Each tire was given a good scrub and heat cycle well before test day.
Skidpad Test
Ambient temps were in the mid-80s, so we were careful to isolate tire overheating as much as possible on the skidpad. After a trio of wake-up laps, each tire was run initially at pressures of 36, 30 and 24 psi for three counter-clockwise laps.
We then sprayed the tires with water and went out again at 24 psi to see if the cooling mattered. Finally, we ran the circle clockwise to further w in the pressures, this time putting the cooler tires into play.
Since the BFGoodrich won our last test, it went out first with David at the wheel. The BFGoodrich felt nervous at 36 psi but settled down at 30 and 24, with the latter yielding the best lap times. After a spraying, the BFGoodrich turned the best single skidpad lap we’d ever recorded on a street tire: 9.4 seconds. But the tire immediately reverted to its previous times for the remainder of the three laps.
After turning the car around, the best times were clocked at 27 psi, though the best subjective feel for the rear tires came at 25 psi. We concluded that 27 psi up front and 25 in back would be optimal.
Next up was the Bridgestone RE-71R, which turned out to be fairly pressure-agnostic as far as lap times were concerned. Its feel could definitely be tuned, though, and lower pressures yielded the most driver confidence. Ultimately, David was happiest at 26 psi in front and 24 in the rear. Spraying water didn’t yield a single quick lap, although it did seem to keep the times tighter through our three-lap sessions.
The Yokohama A052 behaved similarly throughout this exercise: fairly indifferent with a preference for lower pressures. The Yokohama also required significantly less steering input than the others, making it much easier to place right next to the cones. We eventually settled on 27 psi up front and 25 in back, but the big news came after we sprayed the tires: another lap record at 9.28 seconds.
Autocross Test
Autocrossers compete in a variety of weather conditions, and temperature can have a strong effect on grip levels. But there are ways to fight back against the weather. Cold tires can be preheated by a co-driver and kept warm between runs with blankets or covers. Heat can be minimized with a water sprayer.
Paddock wisdom says the Bridgestone RE-71R activates at cooler temperatures and has less tolerance for the multi-lap loading of a ProSolo event on a hot day. The BFGoodrich Rival S seems to require a bit of heat before putting its best foot forward–and then it can keep performing for many runs thereafter.
Considering its track-focused heritage, which way would the Yokohama go? The skidpad surely indicated a cooler preference, but would that apply to the full test course?
COLD TIRES:
Each tire was first run cold for a single double-lap pass. David took these runs since he was most familiar with the car.
“The first couple of turns felt terrible, but then grip started to come in,” he said of the BFGoodrich. He gave it a confidence rating of 4 out of 10. Lap times reinforced those impressions as his second lap was three-tenths faster than the first. That trend continued through to his hot test runs, where another half-second came off the clock. Tribal wisdom confirmed.
The Bridgestone cold laps, by contrast, were very consistent, showing no significant improvement throughout and earning a confidence rating of 8.
The real head-turner was the Yokohama: It showed remarkable prowess when cool and was the quickest of all by two-tenths per lap. David gave it a 9 out of 10 in driver confidence, stating how much easier it was to pilot precisely.
WARM TIRES:
Now that the tires had some heat in them, we tested them in a more typical competition environment. Both drivers praised the BFGoodrich for its predictability in the slalom but noted vagueness elsewhere. Our two drivers set many of their fastest times on the second lap of each run, with Andy clocking the quickest at 23.7 seconds and a best full run of 47.8.
David was way more consistent on the Bridgestone RE-71R, cranking out laps all within a tenth and a half of each other. “Everything just feels better,” he reported. Andy’s runs were mixed, but he praised the Bridgestone’s responsiveness, ability to accelerate out of turns, and confidence at the limit. Quick times were 23.8 seconds for a single lap and 47.8 for a full run.
After laying down those magical cold runs on the Yokohama, David slowed a bit by his second set of passes. However, he noted an advantage over the rest of the field: a wider plateau of grip near the limit, allowing for easier mid-corner corrections. Andy’s times consistently improved on these tires as he adjusted his inputs to match the Yokohama’s smaller slip angles. “It has the sharp response of the Yokohama AD08R combined with the grip of the RE-71R,” he noted. Quick times were David’s 23.6 single and 47.5 full run.
To help isolate variables like course cleanup and driver familiarization, we bracketed our testing with a final set of runs on the BFG. This time, David was more consistent while Andy had a bobble on his third lap. Both drivers were a touch slower than before, perhaps due to late-day fatigue, but the times were within a few tenths of the first round.
Bottom Line
This was just an isolated experiment, but the results point to a clear conclusion: Yokohama has delivered a real player in this market segment. No longer is the choice simply between BFGoodrich and Bridgestone; Yokohama now has to be considered.
The Yokohama will especially come into play when tire warming isn’t an option, like during the final ProSolo rounds or on Lincoln’s cool mornings. In average conditions, though, the Yokohama A052 looks to be simply another equally capable contender. Its price is also right in the ballpark:
- $221.45 in our test size versus
- $191.12 for the BFGoodrich and
- $246.23 for the Bridgestone.
Will the Yokohama become a new benchmark as cars and drivers adjust to its unique traits? If it does, how will other tire makers respond? Check back with us this time next year when we’ll have those answers–and some new questions.