but i noticed somthing.....theres a big diffrence from the front and back, the back are alot bigger than the front? is this going to look alright on my car? sorry this my first wheel and tires that i have purchased. wheels are boyds smoothie2 17x8 (4.5 bs) 17x10 (6.0bs) tires are yokos AVS es100 245/40/17 front and backs are 275/40/17

 

there not on my car cause im working on the exhuast and suspension....sorry last one

 

you got the wrong size fronts , i have a 245 40 18 and you needed a 245 45 17

 

i searched for hours....days lol i thought i had it right, u think it would look right on my car?

 

no i dont think it would looks right , the stock ones look too small as it is , i see you have stickers on them still , i know it sucks but dismount them and send them back to tirerack or whever you got them and get the right size.

 

yeah they are definatly the wrong size. the first number is the tread width in millimeters- the second # is the aspect ratio % of sidewall to tread width. if you have the same aspect ratio- but ones wider- the one will definatly be taller. find a tire calculator- you can put the sizes in and itll tell you total highth and width.

 

there are quite a few 3rd gens running that size front. It will be fine. Im running almost the same i have a 235-45-17's and they look fine and match the rears in height pretty good.

 

Yeh 245/45/17 was the size you need but its on the front no big deal if it looks ok.

 

245/45/17 up front and 275/40/17 in the back is not a problem. You just can,t rotate.

Those are probably the sizes I will go with when I get my ROH ZS wheels.

 

just throw them on and see if you like it, they are already mounted. If you dont like it send it back.

 

Those are the exact same sizes I run. They will be fine.

 

i know the back are 2 inch's wider than the front but i didnt know that u needed to get a taller tire on the front 245/40 and i needed 245/45. i thought both my front and back are 40's they would be the same height

thanks everyone

 

those are cool.throw them on and

 

size is fine
nice wheels.

 

Those are going to look great! What'd you pay for those and how long was the wait?

 

yeah hold up your talking the difference of

245 45 R 17 and

275 40 R 17

There is barely any difference in the two sizes the aspect ratio between 45 and 40 on that tire is almost non existant

your side wall will be a tad shorter than a 45

you dont need a taller tire on the front...who told you that? 4th gens come with 275 40 17 all the way around and they dont look wrong do they?

YOU GOT THE RIGHT TIRES dont worry about it you shouldnt have any problems (i work at discount tire)...just throw them on take pics and let us see them

 

Godspeed you got your sizes all messed up
http://www.miata.net/garage/tirecalc.html
Go there and compare 245/40/17 and 245/45/17

 

You are talking about an overall difference in tire diameter of about 1 inch (0.96 inches to be exact). However, I have seen some people run that size in the front. The only thing that could look strange is if the fender gap in the front ends up being larger than the gap in the rear. It could make the front looked raised just because the tire is smaller.

GodSpeedGTA - No one told him he needed a taller tire on the front they just said that a 245/45 is the same height as a 275/40 and the 245/40 will be shorter. 4th gens don't look wrong because they come with 275/40 tires on all four corners which are the same size.

BulliTooth - The wheels look great and I would try them first and see what you think. I have seen people running the same size tires as you and they don't look bad at all. The front of these cars tends to sit lower than the rear so I don't think the fender gap issue I talked about will be a problem.

 

the place i got them said it wouldnt b a problem if i wanted to get the 245/45 so im going to go with them. im working on the car so i dont know what they would look like mounted. i got long list of upgrades so it might b awhile, ill post a pick when its done

82firebird i paid about 1600 for everything took about 8 weeks. i REALLY wanted 18 but my wife game me a budget

thanks again everyone

 

good move going with the 245 45 , i think its a good choice. Its the correct size to get , so go with it .

 

I run that exact combo on my Iroc well....the 245/40/17 with the 275/40/17, I have had no issues at all. They look great and the size is just right.

 

245/40/17=24.72inches total
245/45/17=25.68inches total
Yes there is a major difference in total height, but there is nothing wrong with the size of 245/40/17.
275/40/17=25.66inches total
So 275/40/17 is a tad bit shorter than the 245/45/17

Here is the formula for finding the total size.

MM size(245)x Aspect ratio(45/40) hit % then divide by 25.4. Multiply the total by 2(4.34x2 for the 245/45)then add the size of the wheel. You then get the total height. You will get of 25.68.