Car Advice

Toyo Proxes R1R – Road and Track Test

30 Sep 2015

Robert Pepper

One of the easiest, quickest and greatest improvements you can make to your car is to change the tyres.  We put the Toyo Proxes R1R to the test.

WE HAVE FULLY explained how to choose a new set of car tyres on this page, but here’s a recap.  My Toyota 86 is pretty much a toy car used for grassroots motorports, but also has to do duty as a daily driver if I don’t have a press car to write about.   Toyo offered us a set of tyres to test, and after due consideration we arrived at the R1R – this is a tyre designed for motorsports, but also tame enough to use day-to-day and in the wet. We kept the size the same – 215/45/17 (explanation of sizes here).   The R1R is not Toyo’s ultimate motorsport tyre for track work, as there’s also the Proxes R888 semi-slick, but that’s not a daily-drive tyre.

Toyo R1R Specifications

• Design – the R1R is a directional tyre, which means it works better forwards than reverse. This is normal for high-performance tyres, but it does mean that you can’t swap tyres from left to right of the car.  You wouldn’t choose directionals for long-distance touring.
• Size – 215/45/17 (a stock 86 tyre size on the GTS model, and also the Subaru BRZ)
• Raring  87 load rating, W speed rating.  This is the minimum requirement for the Toyota 86.  The R1R’s  treadwear rating is a lowish 140.  Treadwear ratings are a measure of how long the tyre will take to wear out, which in turns means they are a rough guide to grip because in general, the grippier the tyres, the shorter its life.  There’s more to tyre grip/life than that, as there’s various other factors to consider such as noise, cost, comfort and so on, but nevertheless treadwear ratings are not bad as a first-glance indicator.
• Features – Toyo say the R1R’s design features include:
  •  A silica-reinforced, high-grip tread compound, a tapered center block edge which stabilizes center block movement to decrease irregular wear and helps to increase hydroplaning resistance. 
  • Stability Control Slits provides resistance to irregular wear and improves dry performance by maintaining block stiffness during aggressive braking.
  • Multi-Width EVAC Channels improves water evacuation and widens the shoulder block area to enhance steering response.
  • A Unidirectional Arrowhead Tread Design provides balanced performance between wet and dry conditions.

The tyres are a little less than two years old.  It’s always important to check the date of any tyres you buy, particularly if you get them at a discount…had a mate who picked up a set of tyres nice and cheap, only to find they were four years old. Ouch.

On the street

Let’s start with the obvious, the looks. 

The R1R looks like a serious tyre with its directional grooves, more so than the stock tyres on the 86 which are either Michelin Primacy HP (GTS, BRZ) or Yokohama Decibel (GT). The squarer shoulders also look better than the more rounded, conventional shoulders of the stock tyres. It’s not a big difference, as you can see from the photos below:

Most people swapping tyres will go for wider rubber as the 86 needs to fill its guards a little more, and a 235mm section seems to be more or less optimal for these cars as far as trackwork is concerned. While these tyres on test are the standard size of 215/45/17, there’s also a 225/40/17 which will fit on the car’s standard 17×7″ rim but is about 13mm shorter so 7 mm of ride height lost. However, if you want to go any wider, say to the 235/40/17 then you’ll need a rim of 8 to 9.5″ in width.

Around town there’s four differences from the stock tyres, two positive, two negative.  Positives first – the largest, and most noticeable difference of the four is the extra grip. The 86 is a rear-drive sportscar set up to some extent for oversteer, and has a throttle response that is on the sharp side of immediate.  Most variants of the car also have a powerful Torsen limited-slip differential. What all this means is that if not driven gently the back will dance out, restrained only by the electronic stability control system. And plenty of panelbeaters can happily attest to what happens when that’s switched off. 

You notice the extra grip everywhere, but particularly in the wet, and around slower roundabouts. The R1Rs do not turn the 86 into the sort of limpet traction machine that would rival a WRX, but they do mean there’s less delicacy required.  Whether you consider that good or bad is your opinion. You’ll be able to stop quicker in any emergency, and that would be a good thing.

The other positive is handling. The car turns in better, feels more responsive to steering input and precise. It’s not a massive difference, but it is certainly quite noticeable on a back-to-back drive.

The two negatives are minor, and again only noticeable on a back-to-back drive. They are harshness of ride and noise, both points on which the R1Rs are not as good as the stock tyres.  It is not however a major issue as you don’t buy an 86 for its ride comfort nor its refinement. Or you could argue the opposite and say you don’t want to make it worse. Either way, you quickly get used to it. I drive a lot of cars, perhaps six every month and make a lot of phonecalls – my friends and colleagues can tell when I’m in the 86 because they have difficulty hearing me.

On the racetrack

The first outing for the R1Rs was a trip to Phillip Island, a track I’ve spent more time on than any other.   With the stock tyres I’ve managed a 2.00.4, and on a set of Nitto Invos a 1.57.3 on the same day in the same conditions which were dry, moderate temperatures and wind.

The R1Rs aren’t a R-spec (race specification) track-dedicated tyre like Toyo’s own R888, so it would be unfair to expect them to perform to those levels.   However, they are a directional, high-performance tyre with a low treadwear rating, and not a low-budget choice either at around $1000 street price for four fitted, balanced and aligned. So my expectation was to be able to shave at least a second off my previous best time, if not two.  Toyo recommended pressures of 35psi hot, so I started at 30 and bled air at the end of the session.   The second and subsequent sessions were 35 hot exactly.

I did my best, but managed only a 1.58.5, only two seconds quicker than the stock tyres in pretty much identical conditions.   For the fifth and final session I went to 40 hot…made no difference.  Perhaps 32 hot would have been better, but there’s only so many sessions in the day.

A good benchmark at Phillip Island is the run out of Turn 10 (known as MG, the hairpin right at the bottom of Lukey Heights).  With the Primacys I cannot hold the car flat from the exit of turn all the way onto the straight as I get fourth-gear oversteer on Turn 12.  Can’t quite do it with the Invos, and nor with the R1Rs although it’s not far off.  Of course, you could hold it flat and just deal with the oversteer but that’s slow in a car of the 86’s power, and Turn 12 is a notorious wrecker of cars so it’s not wise to tempt it.  Last crash I heard of there cost $13k to fix an 86, and the driver considers he got off lightly.

The next weekend I went to Sandown Raceway, nobody’s favourite track.  Especially not in the 86 which is more about corners than straight line speed.  The weather was good – dry and warmish, same as my previous run. The best I’ve done with the Primacys was 1.33.0, the R1Rs saw 1.31.7.   A useful improvement, but again not quite what I was hoping.  Pressures were 35 hot again.  The track did highlight the R1R’s handling though, really does give the confidence to push knowing that when the limit comes the tyres won’t snap the car into a world of pain.  When the limit comes – be that oversteer or understeer – the car is easily recoverable, and you can feel the progressive loss of grip.   Provided of course you approach the limit smoothly and gently, obviously if you throw the car over the edge the result will probably involve a red flag.

An interesting point about upgrading tyres is the brakes. Ideally, you want to be hearing the ABS work (but not go mad) pretty much every time you enter a corner, as that indicates you’re using all the available traction.   The stock calipers I use aren’t really up to the job of overcoming the tyre’s grip at speeds over 100km/h, so there’s a bit more time to be found there as I couldn’t always get the ABS coming in as I’d like.  But not much, laptimes are more about cornering and exit speed than fractions gained under brakes.

A note on the Invos.  These were 235/45/17 on aftermarket forged rims.  This means they are 20mm wider than 215/45/17, and about 2.5% or 18mm taller which means 9mm extra height.  The extra width would mean more grip in the corners (not via a greater contact patch, but a wider one) and more drag on the straights.  The extra height means taller gearing, but it’d be barely noticeable.  As the rims have a different offset the track (distance from centre of wheels) is wider too.  So it’s not a direct comparison from R1R to Invo as they’re different sizes.

Here’s a table of the various tyre and rim weights:

The R1Rs are barely any heavier than the stock Michelins, which is good going considering they are a stronger tyre designed for high-speed work.  It should be noted that rotating mass is bad news – any weight is bad for performance cars, but tyres/rims in particular should be as light as possible because it’s unsprung mass as well as rotating mass. 

Essentially, changing tyres involves a lot of factors like that and many more, and this test was not sufficiently controlled to all account for them all.  However, the base results appear to be sound.

Summary

R1Rs and drifting

The R1R is a popular tyre in the drift scene both in Australia and aboard, most recently winning the D1GP (Drift 1, Grand Prix) series which is in effect the world championship for drifting.

Masato Kawabata drove a 745kW 35RX D-Spec Nissan GT-R to victory, wrapping up the series with several rounds still to go. And that’s on street tyres you can buy today, the same ones on test here.