Vince

Just got the x coupe. It has 18" wheels with 225/50R18 Dunlop’s. I really like the Infiniti 19" wheels and got the dealer to give me a great price as a second set. I'll use the 18's for the winter and 19's with performance tires for summer. The dealership service manager cautioned that all the tires/wheels have to be the same. He suggested going with 225/45R19 on the 8.5" wide wheels all around. He also cautioned not to go wider 'cause they will stick out. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>
Any comments / suggestions? <o></o>
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Mike

iTrader: (1)

You can go wider, but make sure all 4 rims and tires are identical.

Triple_X

iTrader: (3)

^^ yup I did 255/35/20 all around, stinks I know.

Neal@tirerack

iTrader: (2)

Yup keep same dia so all plays together nicely.

Mike P

iTrader: (1)

What does staggering do? Why is it so bad? The 255 or 225 is given, but why not 45 in front and 35 in back or whatever?

Neal@tirerack

iTrader: (2)

Stagg fitment is fine as long as the diameters are the same. Running a taller tire out back vs up front on an awd car will eventually damage the drivetrain. Front of the car has to rotate at the same rate as the rear or things will work against each other.

Here, check this link out Matching Tires on Four-Wheel Drive and All-Wheel Drive Vehicles

Vince

Any problem with "road spray" on the sides of the car with those tires? Do you have splash guards (front back)? What width wheels do you have?
Thanks.

Vince

Neil,
Just how close do the tire circumferences have to be? Is the difference with the same tires, say 225/45R19 on 8.5" wide wheels in front and the same tire on 9.0" wide wheels in back a problem?

Neal@tirerack

iTrader: (2)

Installing the tires on a wider wheel won't change the overall diameter. 225's are only designed to fit up to an 8.5" wheel though so I'd be surprised if they wanted to seat properly on a 9".

Vince

Excellent info! Thanks.

Neal@tirerack

iTrader: (2)

Not much at all. For instance, the Lamborghini Gallardo and Murcielago supercars feature permanent 4-wheel drive with a viscous traction system and electronic traction control systems. They are awd and staggered fitment with the diam 1.6" different from front/back. That's ok as the car is built for with that in mind. However, a .5" difference in overall tire diam front/rear when the tires wear, or are replaced on just one end of the car, caused excessive driveline wear and eventually ruined it.

Obviously every car is a bit different but that's an example of how close the tolerances can be. Not sure what the exact threshold for Infiniti is, but we have had customer's report issues both short and long term with tires as little as half an inch off.

Mike

iTrader: (1)

In my experience, the biggest problem with the tire diameter being off on the Infinitis is that VDC (stability control) starts acting up.

The VDC functions via wheel speed sensors mounted individually, and a speed sensor mounted in the tranny, and when the wheel speeds are not at the same ratio as from the factory, VDC will think you're not in control of the car.