Roffles

This really makes me wonder about the placebo effect. My IS-F, which I bought used, came with Yokohama Advan's in the stock size. I wonder if folks who have the stock Potenza's or Pilot Sports are coming from a different perspective. I drove the Yoko's around this earth for ~15,000 miles and never thought highly about the F's handling ability. In fact, I often thought the 5.0 wal too powerful for the chassis... it would get tail happy in corners too easily and traction control lights would always light up in 2nd and 3rd gear shifts in straight to near-straight line acceleration. It didn't inspire too much confidence. Then I purchased the PSS in the 275/245 configuration and all of the sudden I could bang corners as hard as I wanted and straight line acceleration (especially the 1st to 2nd gear shift) would hook up really clean. Was it really all in my head? I remember the first week of owning the oversized PSS and hitting some corners... I would laugh out loud in disbelief at the difference in the car's abilities. One thing for sure is that I didn't see the traction control lights on the dash nearly as often.

I8ABMR

Those S04's looked amazing !! When I saw the tread design I felt great about putting them on the car. The issue in my opinion comes from the size of the tire not matching the width of the wheel creating a softer sidewall. It's disappointing because the car looked great with the tires on them.

When I took it for a ride the car felt very strange. The rears felt like they were very low in pressure. I even pulled over and checked the pressure because I was sure the tech just didnt put enough air in them. When I checked the tires were are 38 psi ( not oem 36) ,but honestly I would have sworn they were at 18 psi from how the felt. The car felt more like a snake than a performance car. It was like the rear of car the was following the front. The response and sharpness was gone. The front of the car felt a little more numb in the steering, but I didnt feel like there was any issue there. I will admit the ride was softer than the PSS. Even at the larger size the ride was smoother. Even at speeds at 25-35 mph I could feel that sidewall flex just jerking the wheel back and fourth.

When I was doing my research I checked out an auto engineering forum and the members there said to leave the oem size BUT to upgrade the rubber. I still think I may try the PSS in the 245/275 at some point though. From what I have found is that the reason these tires and most tires on most performance cars have that very mild stretch ( sidewall bends in ) is because it is supposed to aid in sharpening the handling and response. In my experience they are 100% correct. I thought that all of this was splitting hairs but its not. The suspension and tires are truly a symphony. Sometimes telling a certain instrument to start playing louder or softer just creates a loss of the harmony .

Its odd that I had this experience when so many of our members feel that the car feels more planted. In my opinion, on my ISF, this set up would be a disaster on the track. I have not tried the PSS on the track yet but I will very soon. With the oem Potenza RE050A the steering was very sharp and the car would take corners like a razor. I am very much looking forward to trying the PSS on the track ( even at oem size ). I will be doing a write up on the track day and the new PSS. In fact I will take photos of the tires when they are brand new ( they have less than 800 miles on them ) and how they hold up after each session.

In the end my goal was to add more balance and grip . I am sure that with the Michelin PSS I got some of that. How much ?? Not sure, but we will see how they handle on the track. Out of the box we all know that the ISF tends to understeer. Many of us solved this issue with the sway bar. In my case, the rear sway bar with the worn RE050As started to create corner exit oversteer on the track. In my case ( mistake ), I ran my F on the track with my TCS on. I just didn't have the confidence in a car with 416 HP on the track exiting a corner hard with tiny 255s. I was concerning I would spin and look like an *** ( like the C6 vette and S2000 that took a spin in the run off area and a nice dirt bath ). I will try it this time with the PSS and the TCS off. In the short time I have had the PSS I must admit the car feel amazing and I still haven't managed to break traction unless I do some silly crap . We will see how she does on the track !!

darbs242

iTrader: (5)

I run toyo proxy 888 in 230 and 265 on factory 08 wheels and really like it. i would like more tire up front.

I8ABMR

I actually looked at the R888 but they didnt come in oem size. Im sure they stick. They put those tires on TT Lamborghinis

LexusISF19

I8 what year js ur isf

I8ABMR

2010 buddy. I have the narrower wheels. Im am hyper sensitive and the wider tires on the oem wheels will just not work for me on the track let alone the street. In the end the engineers know a thing or two.lol

kiryu

Guys sorry to sidetrack the discussion. I have a noobie question
Is it true that when you go wider than oem 225/255 your mpg is going to suffer? That's why Prius have skinnyass tires?
Thanks

lobuxracer

iTrader: (2)

In a word, yes. My mileage under the best conditions got worse when I put 245s on the front.