Hey

I drive a 2013 (2009-2013 shape) panamera base diesel. On my manual it says the tyres in 18" category should be 245/50/R18 up front and 275/45/R18 at the back. My Panny (still on factory tyres at 27k) has right size on the front but my back tyres are strangely at 255/45/R18 and when i called up the local dealer.. advisor told me some cars do come with different tyres... can this be correct?

anyone here with a panamera base or diesel model verify this?

Also any suggestion on right tyre pressure for 18" tyres. i'm looking for stability and tyre safety on uneven roads more than comfort alone.

Please advice as tyre pressure thread posted earlier relates to 22"

 

The wheels are 8 x 18" front, 9 x 18" rear. That's 203mm wide front, 228 mm wide rear.

The standard tires are indeed 245 / 50 / 18, 275 / 45 / 18. That means they're respectively 245mm and 275mm wide. The front sidewall is 50% * 245 = 125mm, the rear sidewall is 275 * 45% = 124mm. I suspect there's some rounding and they're actually the same sidewall width, and hence the same overall diameter.

Wheels can take tires that have a range of widths. Generally you don't go narrower than the width of the wheel, or more than about 20% wider than the wheel.

Your current rear tires are 255mm wide, which is well within the tolerances, though honestly they seem a bit short. I'd expect 255/50/18, not 45. 255 * 45% = 115mm sidewalls.

I can't say why you have those tires, or whether that's normal.

Recommended tire pressure should be marked on the door.

 

Im not sure if my dealer had something to do with swapping out my tyres before delivery... even tyre pressure on my door says 245/50/R18 or 275/45/R18 tyre pressure along with 19 and 20" tyre pressures with different sizes.

not sure what to do now. i guess will have to run those tires out and then put new tires.

 

That's the thing to do. From what you said about tire mileage, it's probably time to change the rear tires soon anyway. Check them for wear, particularly the inner edges, which tend to wear faster.

 

For some very odd reason Tyres were non standard at the rear so replaced both with Pirelli P zeros N1 (excellent feel as of now). Coz of crazy indian taxes two tyres costed me 1000 USD.

Now I'm ordering brakes from USA as a friend is coming to visit me. Brake pad replacement job at Porsche dealership is for 2500 USD front and back without rotors. just brake pads so ordering this from usa. as of now just wondering if you need to switch Anti Rattle springs each time you swap the brake pads... thanks.