Squirming

Perhaps there's something wrong with this thread's tyres.

I was just going to show you the book, but then I found this:
prawncocktailyears.com/2014/03/the-challenge/

Going to have to try it now.

A good prawn cocktail  is a thing of awe and wonder.  The George Hotel in Stamford does fantastic ones. 

Back to squirming. Must give the chariot a thorough tyre check once it's light this morning. Yesterday's rainy drive to Wallingford felt horrible, and not just because of potholes and standing water.

Since I first wrote about this here I've been trying to refine my account of what the car does and how it feels. It's not that it doesn't ultimately go where I tell it to; more a question of precision and feel. It's never been a car you could cruise along a country road with one hand on the wheel, but that used to be more about needing two hands to keep it smooth. Now it wants to follow every bump and camber change, and straddling the crown of the road to avoid a puddle gives the unnerving - and fortunately misleading - feeling that it's going to wander right over to the other side.

But it never actually does any of these things, just feels uncomfortably like it might. And on a motorway it's as secure as ever and runs straight on with no hands at all. I'm suspecting that the front tyres may be wearing to the point where the edges don't grip immediately as they begin to turn left or right, in which case I'm inclined to change them even if the gauge suggests there's life left in them.

Taking the Audi case as closer to mine, did the tracking problem mean it felt bad all the time? Mine is very much at medium speeds; at town speeds the tyres don't have enough to do to get out of shape, and on the motorway the steering deflections are possibly too small to upset it.

I checked the tyres. Pressures were maybe 5-10% below the door sticker values, so I pumped them up and tried a bit of yesterday's route again. Same feeling. I also checked tread depth; the 255/35 rears are about 5mm right across, while the 235/40 fronts have 5mm inside and centre but are down to barely 2mm on the outer edges.

The E90 series being well documented on the ever-reliable internet, it seems they have a known tendency to wear out the inner edges at the back - no sign of that on mine - and for the coupés in particular to wear the outer edges at the front. This is exacerbated by the run-flat design, so that instead of flexing as the load shifts sideways in a turn, the stiff sidewall pushes back and lets the tread do all the work. Apparently over-inflating can help, and I've noticed that my car rides better with higher pressures, perhaps because more shocks go through the compressible air rather than the unyielding sidewalls. Upping the pressure closer to the full-load value seems to have helped the steering feel too.

Either way, I suspect it may be as simple as 'they all do that, sir'. BMW owners seem unanimous in their distaste for run-flats, but I don't see a viable alternative, given that the week I installed anything else is bound to be the one when I get a puncture in the rain on the M4 and am left with no way home. There's nothing for it but to change the front tyres soon, so I'll go for Michelin and hope that my general experience of longer life and better steering feel holds good for this car too.

Prob'ly just that you're used to a more premium feel from your other car...

😉

Check for worn suspension bushes WDB. Quick, cheap and easy check.



I noticed my XJ beginning to develop a twitch, especially on fast roundabouts and corners. Nothing alarming but it wasn't as it should be. Spanner man diagnosed a worn bush on front nearside lower control arm (XJs are notoriously hard on suspension bushes). I had both sides replaced and it was back to it's usual magic carpet.