Ok The Vredesteins have done a few miles now (about 150) and although they still have the little spikes that Jim seems to love so much
they seem to have settled down now and are gripping more like I would expect.
No obvious wheel spinning on the inside tyre when accelerating on a tight bend as it was initially, and grip seems pretty decent overall for what is essentially a modified winter tyre operating in "summer". However I do notice that the tyre is very "soft" compared to the previous summer pair, primarily in the sidewalls. I guess that is to be expected however I'm thinking that I might need to up the pressure a bit, at least while they are being used in warm weather.
It does seem to bounce a bit on the tyre at the rear at the standard 36 psi, also I notice on smooth seal at low speeds if I hit the go pedal there is a rushing noise from the back that sounds like tyre tread deformation from an under-inflated tyre which goes away when I ease off the power - never heard anything like on the previous tyres. I can notice on cornering that the rear moves a wee bit as well, probably also due to sidewall flex. So what do people think about raising the pressure to say 38 psi in the warmer weather to stiffen the sidewalls a little bit ?
Is the car manufacturers recommended pressure (of 36 front and rear) even valid when switching to radically different tyres like All Seasons, or does it take a little bit of trial and error to find an optimal pressure for them ? I've never used All Seasons or winter tyres before so I don't have any prior experience of whether tyre pressures need to be altered or whether the really "soft" sidewall is a characteristic that you just live with with these kind of tyres.
Regarding the ESC giving false alerts - that seems to have stopped now that they are gripping better, however I have noticed the occasional odd behaviour on the cars regenerative braking. It has a needle on the dash that shows power use and regenerative braking, a few times now I have noticed that while I'm at say 30mph going down a hill with my foot mostly off the pedal, the regeneration indicator which would normally be steady was fluctuating up and down a bit, (without me moving the pedal) as if it was trying to vary the braking.
It occurred to me that the mismatch between front and rear tyre rolling radius (with the rear tyres being too big compared to front) would make it think the rear wheels were turning too slowly during regenerative braking, and that as a result it might ease off the regeneration in an attempt to prevent "impending lockup" of the rear wheels, which is really just the rear wheels turning a bit slower than normal.
I've also noticed that full blown emergency braking doesn't seem as good as it used to be, even though the tyres aren't locking or skidding in any way, nor does the ABS seem to be activating.... it just seems to be lacking a little in bite under hard braking. I then realised that perhaps the speed mismatch is causing the car to disable regenerative braking under hard braking leaving only the drums acting on the rear wheels instead of drums+motor regeneration.
Normally you would have discs at the front and drums+regeneration at the rear, and I suspect the drums on their own without regeneration aren't very powerful and can't make the most of the wider (than the front) rear tyres.
Hopefully if this is what's happening replacing the front wheels with the same make of tyre and increased rolling radius will solve the problem.
I didn't think any cars still used wheel studs...
No thanks.
