Jay

Last week I had the PS4's replaced with new ones. The old ones lasted for just over 18000 miles, which I think is reasonable.

Great looking car! Have fun!

I compared the mileage with my former cars, which I used in the same way. Commuting makes the majority of the distance. Due to Covid there was less traffic, so I had to brake less. One would expect a positive effect on disc wear. I bought the car with about 25k, so maybe the first user was hard on the brakes. Regarding brake pads, I never had them swapped during my 25k miles.

Yes, genuine Toyota. I'm not racing the car, so let's see how long these last. I bought the car used with about 25k, so maybe the first owner was hard on the brakes...

Today all four discs were replaced, after 50000 miles only. I'm aware that an automatic requires a little more braking, but I've been driving automatics for the past 23 years. The front discs of the Mercedes and three Lexus' lasted for over 70000 miles, while the rear disks easily lasted for 140000 miles. Any thoughts on this?

Nope! The circumference of the tyre cannot be affected by ride height. 😉

Today I finally got to get a go at the German Autobahn with my 2017 GT86 with automatic gearbox. The weather conditions were rather good, with an air temperature of 20 deg. C, a blue sky and almost no wind. The speedometer read 234 km/h or 145.5 mph, which is above expectation. The car is in stock condition, apart from the 225 PS4 tyres, which have a 1.4% larger circumference. Remarkable is the noticeable extra power at high speed. I guess the air gets somewhat compressed when scooped in. The stability at those speeds is pretty good. All in all a satisfying result. 😊

A friend in his S2000, getting instructions to improve lap times.

No difference here. All my cars got hit by debris. After 200 k miles, bumper, bonnet and windscreen have always been a minefield.

It's been quite a while, but I finally capped the generator tube. The car now sounds lifeless. I tried it for 80 miles. I'm gonna remove the cap and maybe try one with a small hole in it, as written before.

I don't know about fuel consumption yet. This varies heavily, as our cars have two faces regarding consumption. I'm quite sure that a wider tyre with more grip will burn some extra fuel. From the specifications I'd guess it may cost you an extra gallon per 1000 miles.

I've been commuting all week, about 35 miles a day. Having had lots of rain, I can happily report a huge benefit of the newly mounted PS4's. These tyres definitely offer more comfort on ridges and cobblestones. On large bumps the effect is partly concealed because of stiff springs and dampers. The overall noise level didn't really change. Maybe the noise is composed of more low frequencies and less high frequencies. The car tends towards slightly heavier steering, which seems normal, regarding increased width and lateral grip. Hope to have informed you well.

That's what I expected. The track demands other qualities. That's why professional series use different tyres for dry and wet; even intermediates. As my GT86 is my daily driver, I highly value drivability under a variety of weather conditions.

Rain!!! So I got to test the PS4 tyres in the wet. I went to places were I used to fight for grip with the Primacy tyres. The difference is stunning. The PS4's allow normal acceleration from a corner, without having to control the throttle with one toe only.

The tread feels way more flexible, due to the compound used. The stiffness of the sidewalls is hard to judge. Due to the increased width of 10 mm, the height of the sidewalls increased by 4.5 mm. This may contribute to less stiffness.