I have the Plus Pack fitted to my Insignia which comes with the 245/45/18 alloy wheels and Bridgestone Potanza tyres.

The ride on the Insignia is already much firmer than the vectra,
(no comfort adjustment fitted to the Exclusiv either), I have a couple of questions.

Car came with pressures set at 43psi which is for maximum load, I've since dropped them down to 35 in fronts and 32 in rears which has helped to soften the ride a little. Manual states 'For Comfort' fronts 32psi and rears 29psi.

I assume its normal for the ride to be harsher on these wheels than the standard 17" steel structure wheels which are 225/55/17.

The wheels look nice, and I expected the ride to be a little bit harder with these 245/45/18 wheels but they give a much firmer ride than I thought they would be. Also occasionaly, one can feel a little tram-lining effect feed back through the steering, no doubt due to the wide tyres. Only a touch but you can sometimes feel it.

I assume this is the price we have to pay if you want this amount of rubber on the road.

Lastly, when the tyres come to be replaced, I assume I could fit say 225/45/18 to the fronts which may erradicate any tram-lining, if I so wished... yes ?

Just wondered.