Tire Fitment: 245/40/18 to 255/40/18

[stevechumo]

I'm currently running 245/40/18 tires for the front and the rear on my SC400. I'm thinking to change the rear tires using the same rims to 255/40/18 to gain some traction and wider look. I'm also considering to go to fatter tires of 265/40/18.

So I don't know if the 265/40 tires will fit and look nicer than the 255/40 or the 245/40. Will the 255/40 give an exact additional 5 mm on each side wall? Or will the 265/40 give an exact additional 10 mm on each side wall? Can anyone give me some opinions?

I wish that I can afford to change to the complete 245/35/19 for the front and 275/35/19 for the rear, but I don't want to waste my current 245/40/18 rim set.

Any info. is greatly appreciated.

 

[Edwin_S]

Please do remember that the circumference (?) is gonna change when you go to 255/40 as the /40/ is the percentage of the width of the tire. So that means your speedometer is gonna be off a little bit.

 

[stevechumo]

Please do remember that the circumference (?) is gonna change when you go to 255/40 as the /40/ is the percentage of the width of the tire. So that means your speedometer is gonna be off a little bit.

You're correct. Wider tires will make the car slower and the speedometer gauge will read slower. However, I have the solution for them. I'll turbocharge my car soon. And since I can fix the speedometer cluster, I can change the speedometer gauge to any settings that I want, including the gauges for the temperature, RPM, and fuel.

 

[Edwin_S]

Oh ok, than there's nothing to hold you back then

What width are the rimms? 8J ?

 

[stevechumo]

Oh ok, than there's nothing to hold you back then

What width are the rimms? 8J ?

I'm not so sure but I believe the rim width is 8.5". The 245/40/18 tire just leaves about 4 mm on each side to protect the rim.

 

[jibbby]

Ouch Steve, 8.5 rims are not so look friendly no matter how wide you get those tires to fit the rims...My rear rim is 10.5 and I should have gotten 11.5 rim...Good luck buddy...You should talk to JamesN concerning any rim and tire question....That boy can pick the rims and tires like no one else...

 

[stevechumo]

That's true. 8.5" for the rear isn't good enough. I should have gone at least 9.5" from the beginning. I don't want to get rid of these rims because I like them a lot. Also, I don't want to widen them as you did because that's too much $$ for the 18 rims/tires. I'm just a poor guy having big dreams.:684:

 

[jibbby]

You can always get the fattest possible tires you can squeeze onto those 8.5 rims and then get some spacers to bring the tires out to the fender lip...You will however still see the skinnies when looking from directly behind the vehicle...Your delema drove me crazy for a year and that is why I paid $400 to widen those babies rather then dump all four rims altogether.....

You can always try and sell the rims you have now and use that money to buy wider ones...It's too bad Allessio rims are not made larger then 8.5"...Good luck on this one Steve.......

 

[stevechumo]

...Your delema drove me crazy for a year and that is why I paid $400 to widen those babies rather then dump all four rims altogether.......

:biglaugh:
I'm sorry, John. I couldn't be sad for your $400 loss because the way you said it is funny. I'm still using those spacers and I just don't want to get rid of them. From looking behind the car, the 8.5" rims somewhat look a bit skinny to this SC body. That's why I want to widen them with the spacers to cheat the look. Actually, the 8.5" rims aren't that skinny on a regular cars.

You can sell the spacers back for somebody else and hopefully you can get more than half of what you paid for. The hard thing is to find the rims that have the same centric ring diameter as these Alessio.