Have I Had The Wrong Size Tyres On My Car All Along?

[KrazyKong]

I have a set of stock R33 GTR rims on my GTST. When I first bought my car, it came with 235/45/17s on the front and 255/40/17s on the rear. I've always replaced the tyres with the same sizes. Now I'm not 100% sure, but wasn't the stock GTR Rim tyre size 245/45/17?

Have I had the wrong sizes on my car all this time? I love the look of the staggered tyres and am in the process of narrowing down my options for the next set. But it occurred to me, that either I'm worrying about nothing, or I might actually have the wrong size tyres on my car. Maybe that explains why I'm about 5km under the actual speed limit on my speedo and why people seem to like to tailgate me alot.

Edited April 17, 2014 by KrazyKong

[djvoodoo]

Because of the AWD system on the GTR, rolling diameter at all 4 needed to be the same essentially. Seeing as though the GTST is rear wheel drive, you can have staggered sized wheels and tyres and it will not affect the drivetrain (however height of tyre/wheel can affect speedo)

90% of Skyline owners run very similar sized tyres as what you have, it's very normal.

[GTSBoy]

Yuh, you're fine. The closest to correct size to the original GTST tyres is 235/45/17, but the 255/40s are also close enough.

[niZmO_Man]

5km/h slower than actual is normal. Most cars have that (a quicker speedo).

[KrazyKong]

Ok cool, sounds like things are ok then

Yes having a quicker speedo has probably saved me from 1 or 2 speed traps. It's not something I'm overly worried about, rather in connection with the tyre sizes, it got me originally thinking I might have the wrong sizes.

[Dose Pipe Sutututu]

just wrap all four corners in 255/40/17 - allows you to rotate your tyres