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So, on the hottest day of the year Stan the Man and i decided to swap wheels and tyres over and go for a quick drive and see what we thought. The results are inconclusive for a number of reasons. 1. traffic prevented a decent run at some of the test corners. 2. Falkens are 205/50x15 and R1Rs are 205/45x16 so there is an automatic difference in the 'feel' of the car. 3. STM's 15" rims weigh a ton, which also has a bearing on the 'feel' - my rims are almost OEM weight. 4. STMs RT615s are at the end of their life, my R1Rs have 6000km on them and look hardly worn. However I can comment on some things (subjectively anyway). I found no difference in grip level between the two tyres on my car, so a big tick for the R1Rs there. Comfort wise the 15's were a revelation though - my car was so much less 'crashy' over the bumps and potholes it was amazing - big tick for 15" 50 profile tyres there (I doubt the RT615s would be any different to other 50 profile tyres in this respect). The RT615s are definitely stiffer in the sidewall and are more responsive to the steering wheel, however not hugely so, and I could really feel the weight of the rims when turning in, my steering took quite a bit more effort, which I would find annoying over time. It could be that the weight of the rims is helping the ride too - not as much bouncing around over bumps. Anyway, I'll let STM tell you his impressions when he logs in. A little aside- we discoverd just how much the chassis stiffness differs between the NB and NA - to raise STMs car enough to clear the rear wheel the front wheel was 420mm off the ground, but only 320mm on the NB





And, not content with cooking ourselves changing wheels in the heat, we painted #3 son's car (as a prelude to correcting Patchy's paint problems - the swift is our test mule ). We really are nuts...

It was like a Sauna at Big Dogs place. When we'd done an hrs work & had a rest in the comfy air conditioned lounge room. We'd get back out there & as soon as you opened the door.....far out It must be at least 10deg cooler at the coast.


but as far as the RT615's vs R1R's

yea I think putty road or Bathurst run are in order.


Initial reaction was that I was freaked out at how lite my steering was. OMG!!!

It felt like I was only skimming the surface driving on these tyres. Almost floating. While with the RT615's they feel like I'm firmly planted between the tyres & on the road. But that's not to say there wasn't any grip. There was plenty. We did get the occasional run but I felt I was nowhere near their full potential. It also felt more like a road tyre where the RT615 feels more like a racy tyre.

Both tyres felt very different. Almost like Day & night. I suppose it drives home the point how much difference a lightwight rim makes to the steering.....Patchy felt like it had Power steering.


so......we may have to plan to swap tyres on a club run or something.

That's a good write up. Although the tyres are different sizes, it still give enough info to make comparissions between the two.

I am currently looking at both to buy at the moment. And if I had to choose, then I'd buy the toyos as the are $100 cheaper in 205/50R15s.

Personally I would be going for the Toyos.

but I base that on absolutely nothing apart from brand loyalty, and price.


I know the RT615 is a semi style using street compounds.

but what about the R1R? does it use a semi slick style compound?

i have read on a forum in the states that the r1r uses the same compound as the 888 - but that sounds a little odd. i read on the toyo site that it uses a high silica compound which i spose is similar to a semi slick compound but i doubt that it is actually a race compound rubber. so based on very little information other than whats on their site its a very soft street compound rubber. the wear rating is 140 where as the rt615 is 200

hks_kansei wrote:Personally I would be going for the Toyos.

but I base that on absolutely nothing apart from brand loyalty, and price.


I know the RT615 is a semi style using street compounds.

but what about the R1R? does it use a semi slick style compound?

not according to Toyo - they sell the R888 as their semi slick, but the tread style is definitely a racing pattern with chamfered tread block edges etc, and the compound is definitely soft.

I know the R888 is Toyo's top end semi click tyre, however until recently the R1R was classed as a competition tyre too. It was a sort of comprimise between a full semi slick (Ie: R888) and a street tyre (T1R)

my understanding is that teh R1R is a semi slick style compound, but with more tread cuts and a road tyre style tread.

whereas teh RT615 uses the opposite approach of having a Road tyre compaund with a Semi Slick style tread pattern.

Both are like a middle ground, more grip than most road tyres, but not quite as much as a full semi slick.

16bit wrote:i have read on a forum in the states that the r1r uses the same compound as the 888

I mentioned this to my tyre guy and he said he thinks it's correct. He had measured the "hardness" of both tyres (wish I could remember the name of the equipment he used to test it).

Okibi wrote:

16bit wrote:i have read on a forum in the states that the r1r uses the same compound as the 888

I mentioned this to my tyre guy and he said he thinks it's correct. He had measured the "hardness" of both tyres (wish I could remember the name of the equipment he used to test it).

That would probebly be a durometer, my alignment guy has one. My Bridgestone re001's read 62, his grid 3's about 65, both prety much new... What did the Toyo's read as a matter of interest?

Sorry dunno, I was chatting to him quickly on he phone trying to find the price of T1Rs when he started talking up the R1Rs.

Yes the Toyo R1Rs and R888s use the same tyre compound. And IT IS a medium motorsports compound. But the R888 do have a stiffer/stronger constructed tyrewall compared to the R1Rs.

The RT615s is a hard motorsports compound. But still alot softer than a normal street tyre compounds.

They may well be the same compound of rubber, but the construction could be entirely different which would make the tyre a different animal to the R888. To this point in time they are the best tyre I have had on the SP, but I am seriously considering a 50 profile tyre for future road use when these wear out. If you are fitting them in 205/50x15 profile they should be awesome, if a little soft in the sidewall.

project.r.racing wrote:Yes the Toyo R1Rs and R888s use the same tyre compound. And IT IS a medium motorsports compound. But the R888 do have a stiffer/stronger constructed tyrewall compared to the R1Rs.

The RT615s is a hard motorsports compound. But still alot softer than a normal street tyre compounds.

Just to clarify this. The Proxes R1R has a different tread compound compared to the "GG" tread compound that is used on most Proxes R888s. Compared to the "GG" tread compound, the Proxes R1R tread compound has improved wear resistance / lower grip levels. The statement regarding construction is accurate.

so basically its the same but made to work on the street as opposed to the track?

Thanks Steve, nice to have some expert comment on this. As I think I said earlier Toyo don't regard this as a semi-slick track tyre, they sell it as a street tyre as a step up from the T1R. I chose to fit them after getting 56,000km out of my last set of T1Rs - I figured i could go to a softer tyre and still get good wear out of them. I contemplated fitting PP2's and Adrenalines, but the Michelins were way more expensive, and the Bridestones were $50 per tyre dearer, so I took a punt and am very happy with my choice.