Tyre Pressure For Is250

[finest1]

hi all

im a bit confused regarding the tyre pressure.

i have the standard tyre set up on my is250 sel which is:

front: 225 45 R17

rear: 255 45 R17

what tyre pressure do you guys use? i wasn't sure so i put 32psi in the front and 34psi in the rear

thanks

finest1 :winky:

[steve2006]

It sounds about right but the correct information will be in your owner's handbook.

[Tango]

what tyre pressure do you guys use? i wasn't sure so i put 32psi in the front and 34psi in the rear

With my IS250 SE-L I started with 35 psi all round and then monitored the tyre wear on both axles. If the tyres show signs of wearing more on the outside edges then increase the pressure by a couple of psi and continue to monitor, if they show signs of wearing more in the middle then decrease by a couple of psi. When the wear is even across the tyre then stick with the pressures they're on. If any of the tyres show uneven wear, i.e. more on one side of the tyre than the other, then get the geometry checked and adjusted. Correct pressures will vary depending on the type of tyre, the average loading, how you drive and the type of journey usually done. The user manuals state recommended pressures for depending on type of loading and average speeds, but they should be treated as a starting point, not as absolute.

On my 250 I found 38 psi all round gave me the optimum wear, but that was on 235/35/19 front and 275/30/19 rear. Coincidentally the similar size tyres and rims on my IS-F ended up with the same pressures.

[finest1]

thanks for the info,

owners handbook says 30 at the front and 32 at the rear. didn't realise it should be that low. tyre wear seems ok at the moment, none showing in one place, looks even to me.

one other thing, if i was going on the motorway, should i adjust the pressure?

[Tango]

thanks for the info,

owners handbook says 30 at the front and 32 at the rear. didn't realise it should be that low. tyre wear seems ok at the moment, none showing in one place, looks even to me.

one other thing, if i was going on the motorway, should i adjust the pressure?

Handbook will say to increase the pressure so the tyres will run cooler, but if you're running air inflation heat will cause expansion and raise the pressure anyway. I've always sought to run pressures that provide optimum tyre wear for my average journeys and leave it at that. I'll add that I've found nitrogen inflation appears to give less variation in pressures during regular monitoring, but now I've mentioned it I'm sure it'll generate a load of posts saying it's all hype and air is mostly nitrogen anyway so it makes no difference, yada yada.

[SSSA-IS]

Hello guys.

I am a newbie here. Sorry if Im straying a bit off the topic.

I have an IS 250 AWD 2006 and I currently run: 245/45VR17 at the rear. I just read the first post where he says he runs 255/45VR17. I am planning to do the same. Just wanted to check, if there should be something of concern in the long run with the tire wear? Cheers.