If you go on MX-5 forums for any length of time, although a day is usually long enough, you will come across a new “what tyres shall I buy” thread and pretty soon in that thread someone will say the Toy-o T-1R is the only tyre you will ever need.
Now most people have come to the MX-5 because it is a sports car and even if they don’t want to drive around like a getaway driver, they do want to enjoy the positive handling that the car offers and flying in the face of some pretty heavy internet opinion, I don’t think the Toyo T1R is a very good tyre at all.
So off to Rockingham with a brand new set of Toyo’s and since Kumho has just replaced the KH31, a tyre I rated well above the Toyo, and brand new set of Kumho HS51 to try.
As it is not fair to test any tyre straight from being fitted, the test comprised of 3 laps of Rockingham’s International Super Sports Car Circuit, which is just shy of two miles in length just to give the tyres some bedding in, then a straight line wet braking test from 50mph followed by 5 further laps of the track to see how the tyres performed. This was never intended to be a lap time test or to see which is the best track tyre, but based on normal road driving conditions, so braking and cornering, and seeing what happens at the limits of the tyre’s grip in situations you could easily meet on the road. Rockingham is famed for its abrasion in the dry and its less than stunning grip in the wet. It was a damp day!
I used my wife’s car, a standard 53 plate MK2 MK-5, equipped with ABS and running on 195 50 15 tyres. Tyres were mounted to her normal rims and the tyres were swapped on to them for each test. In this way everything was as equal as I could make it and the ABS would take out any variances in the wet braking. I tried the Kumho first. They got my attention immediately at the first corner, the Deene Hairpin which required a significant amount of opposite lock to keep the car off the grass, they were brand new tyres though and it was Rockingham in the wet, slippy, just like normal roads can be. After the running in laps I went to the wet grip area, this is a section which is constantly sprayed with water to mimic very wet roads. I did two straight line stops from 50mph and then back to the track.
The process was repeated with the Toyo’s, I was much more cautious at Deene!”
Straight away the very first difference could be felt between the tyres, where the Kumho felt direct and positive, ideal for a sports car, even just driving slowly round access roads, the Toyo felt far less so. On the wet braking test the Toyo, although feeling like it was stopping quickly, took a good one to one and a half car lengths further than the Kumho to stop from 50mph. It doesn’t sound like much, but what is the most revealing thing is that at the point the car had stopped on the Kumho, when shod on the Toyo the car was still at significant metal bending speed at that point. Or put another way, if the same car was coming the other way and both braked, the point at which both Kumho shod cars would have stopped with their noses just touching would have resulted in a very substantial head on collision if the cars were on the Toyo tyres
Back to the circuit and the differences were again obvious. The first corner at Rockingham requires braking from high speed, equivalent to any form of emergency braking on the motorway or fast road speeds. The Toyo activated the car’s ABS system much earlier, the car weaving under the heavy braking and tyres could be felt to be snatching on the track, the Kumho however, while it did weave slightly, did it to nowhere near the same extent and felt confident under brakes. Then at the point of turn in the differences were probably most apparent, the Toyo just feels wobbly, you can feel the tread in the tyre leaning over and it just loses precision in the corner. My wife said about her winter tyres “they feel like walking on stilettos in the corners” and it felt the same here, a lack of stability and accuracy. Again, not something the Kumho suffered from. Following on from that, and I hope most noticeable it the accompanying video was the willingness for the Toyo to breakaway in corners (lateral grip) it required a much higher degree of steering input to plot a course around a corner and the breakaway, when it came was snappy and without warning, it was just happening.
In road terms, the tyre is not telling you where the limit is and if you are about to cross it. To me, more than anything this is the biggest fault of this tyre, when it lets go, it goes. Yet again the Kumho just outshone the Toyo in this area, it had more outright grip, less break away and communicated back what it was doing. What may not be obvious in the video is that while there was some break away, it was happening at higher speed and the progression of the tyre gave far more confidence for the corners to be tackled. On the limit the car just took on a gentle drift at the rear giving the car a lovely neutral cornering stance and none of it was sudden. Traction out of corners was similar, the Kumho put the power (what little power there is in an MX-5) down well whereas the Toyo just wanted to go sideways most of the time.
I think in the video I said I like the Kumho tyre, what has proved an extra bonus is it is also quite refined to the point it is noticeably quieter in the car on that tyre as well. My wife, who is quite able to tell if tyres are doing their job or not and who has been running round on these since has also given them the thumbs up.
So, conclusion? Two separate ones really. The first is I think I have proved that my thoughts about the T1R are not wrong, it is just mediocre, maybe even less so and that it has a reputation far above its ability. It is not desperately bad, not like some tyre brands that I have tried that can’t even pull out of junctions in the wet, but equally it is not good and certainly not as good as the internet will tell you. The second is that the HS51 is really quite a good tyre, it outshone the Toyo in just about every area that matters and just that stability of braking and progression in breakaway at the limit is quite possible going to save quite a few MX-5’s from making car shaped holes in hedges. For pretty similar money, I know what I would fit.