Tested: How tires perform on track as they wear | ...

Meet Our Tires

Over the subsequent a number of months, we made common visits in our Triple Threat ND-chassis Miata to Harris Hill Raceway, web site of that preliminary take a look at, to run two or three classes of about six laps every. We swapped backwards and forwards between the Bridgestones and Falkens whereas logging all the info.

After some time, we noticed some attention-grabbing developments. First off, lap instances on each tires have been getting faster–to the tune of two full seconds. These instances have been turning into extra constant, too, with the quickest usually displaying up later within the session.

Lengthy-term Monitor Outcomes

Desirous to know extra in regards to the supply of those anecdotal developments, we devised one other scientific take a look at. This time we’d pit our trustworthy troopers in opposition to contemporary recruits, a brand new, full-tread set of Bridgestone’s Potenza RE-71RS. 

[Ultimate track tire guide | 200tw, 100tw, street-legal track and R-comps]

The massive query we’d reply: Did diminished tread depth and extra warmth biking make the tires that a lot quicker?

Whereas performing this take a look at, we’d additionally must thoughts different potential components: How a lot had the cooler fall climate helped? Was the grime kicked up by close by building nonetheless impacting grip? 

Time to go again to the observe. 

Shaving Off Time

Current rains delivered a clear observe the morning of our take a look at, so we went proper to work. We accomplished a single warmup session on our seasoned Falkens, allowed them to chill for half-hour, after which went again out on them to report instances. 

Displaying its battle-hardened consistency, the Falken delivered 5 laps that have been all inside 0.4 second, firing off a best-ever run on the ultimate go at 1:26.7.

Subsequent up was the worn Bridgestone, now sporting a tread depth of simply 3/32 to 4/32 inch. To not be outdone by the Falken, the Bridgestone cracked off 5 laps all inside a single tenth, twice matching its earlier better of 1:25.6. 

After which got here the second of reality: a efficiency retreat again to the brand new Bridgestone. As in our unique take a look at, the opening salvo was its finest, with subsequent laps falling off. The very best time on the brand new tire was 1:26.3, a full 0.7 second slower than the veteran set, and the session wasn’t practically as constant.

Earlier than we left, we once more mounted up the Falken and did some laps to confirm that observe circumstances and our driving hadn’t modified for the day. Certainly, that they had not; we matched our earlier instances. 

As soon as again residence, the info revealed 5 classes. 

Lesson 1: Much less tread depth enhances each tempo and consistency, at the very least for these two tire fashions. 

In back-to-back testing, the Bridgestone RE-71RS was 0.7 second faster at 3/32 to 4/32 inch of tread than at full depth. And though we didn’t evaluate worn to new straight, the worn Falken RT660 was inside 0.4 second of the full-tread RE-71RS, the place it was 0.7 second off after we in contrast new to new in our first take a look at. This implies that the worn Falken was 0.3 second quicker than new. 

This outcome ought to come as no enormous shock, as shaving road tires is a time-tested technique. That mentioned, there was a interval when the highest canine didn’t profit from it–we’re you, BFG RivalS and Bridgestone RE-71R–and plenty of opponents eschewed the apply. 

Shaving additionally prices cash, each for the operation itself–usually about $15 a tire–and in diminished service life. Luckily, an analogous impact might be achieved just by fastidiously carrying down the tires to their optimum depth as we did right here. It does take some planning, or a number of units of tires, to have them perfected when necessary competitions come alongside.

Lesson 2: The Bridgestone RE-71RS wears down way more rapidly than the Falken RT660. 

With equal use, the Bridgestone misplaced about half its tread whereas the Falken misplaced lower than a 3rd. Plus, the Falken is molded with 12% extra rubber. It might be slightly slower, however the RT660 will ship considerably extra laps than the Bridgestone. 

Lesson 3: Extra warmth cycles might be helpful. 

Our Falken’s lap instances dropped quicker than the tread disappeared, suggesting that this tire mannequin wanted greater than the preliminary pre-test warmth cycle to develop most grip. We’ve additionally seen this trait within the Yokohama Advan A052.

Lesson 4: Diligent rotation between positions will even out the damage, prolonging service life. 

Since we at all times run on the identical observe in the identical counterclockwise course, most of our put on comes on the suitable facet of the automotive, so we frequently commerce our rights with our lefts. Additional, the fronts put on in a barely totally different sample than the rears, so we additionally swap tires finish to finish periodically.

However what in regards to the directional nature of the Falken RT660? That’s solely relevant within the moist for evacuation. Within the dry, you may run them in both course. They’ll be slightly noisier on the road when run backward, although.

Lesson 5: Totally different tires can need totally different pressures. 

Due to our light-weight Miata’s plentiful camber and wheel width, we discovered that sizzling pressures round 30 psi lead to even put on and optimum efficiency with the RE-71RS. The Falken delivered higher put on round 32 to 34 psi sizzling, with no change in efficiency from decrease pressures.

One Final Lesson

Tires stay one of the important efficiency variables. And, as this take a look at exhibits, a single tire mannequin’s efficiency can change relying on its age and strain. 

The trick, as ordinary, is to leverage these modifications to your benefit. One simple means to do this: Take notes.

Full Tread vs. Worn Monitor Outcomes