Hi I have a second gen GS, my friend gave me a pair of tires for the 18" g-spyder that I just bought, they are 255/45/18 , the side wall is slightly bigger than the recommanded 245/40/18.

Then I saw a pair of 245/40/18 tires on sale on craigslist so I grab it so now I have a whole set.
the reason why I did this was just trying to save some money.


now the questions are :

1. Will the 255/45/18 tires fit the back with stock height?

2. Does it matter the back is higher than the front ? ( sidewall ) will it bring any side effect like worse mpg ? plus will it look weird ?? (the back bumper will be up higher now )

3. Should I just find a matching size pair instead ? ( make it 255/45/18 all around or 245/40/18 )

Thanks !

 

do it right or do it twice....that's my motto, and I've broken it numerous times, and yes I've had to do things 2-3 times to get it right because I tried to take a shortcut.

 

245/40/R18
Diameter = 25.7"
Sidewall = 4"

255/45/R18
Diameter = 29.0"
Sidewall = 5.5

I have no idea how it would look but that is a pretty significant differential in diameter. It may accentuate the gap in the front vs the rear. You already have them. Get them mounted and on the car so you/we can see how they look.

Changing out two tires is not a big deal.

 

Good luck on this

 

is it that bad ?

 

it will work. Your speedometer may be off due to the extra diameter. It will look weird having a taller sidewall in the rear, as our cars have a bigger gap in the front. I would try and sell/trade those tires away and get a matching set.

 

try staying as close to oem spec as possible...there's a reason for everything

 

i think it would look kinda funny, just see if you can trade with someone....

 

It will work but like 4ntvings says try to say close to eom spec.

 

lol i think i should get the same set then

 

How did you get your numbers, Debonair? I got 26.16" and 27.56" on the diameters. 1.5" isn't a horrible differential, IMO. I say go for it and try it out. If you don't like the look, sell it off on craigslist.

Big Mack

 

245mm * 0.4 = 98mm
98mm * 0.03937"/1mm = 3.85826"
(3.85826" * 2) + 18" ~= 25.7"
Circumference ~= 80.8"

255mm * 0.45 = 114.75mm
114.75mm * 0.03937in/1mm = 4.5177"
(4.5177" * 2) + 18" ~= 27"
Circumference ~= 84.9"

Speedometer difference is 5.1%. Personally, I would not do it What would this do to things like abs when it sees wheels spinning at different rates? It might be OK in normal driving. I would not want to put it to the test in extreme conditions such as accident avoidance. Maybe I'm overly cautious but I'd sell the 255s and go with 245/40 all around.

 

umm thats true

 

Lazy men work twice..!!!

 

just wondering.........how much did u get the rims for and from where?