guys, i have been thinking to change my tires but i couldnt find 225/45R18 localy.

A friend of mine installed 245/40R18 on stock wheels and he says that everything is ok.

What is your opinion? any difference in height?

 

I have 245/40/18 and they look and fell GREAT on my car.
I can post some pics if you want. (I'm sporting Kumho MX's)

 

I run 245/40 on stock 18" rims. IMHO the tire is an excellant size for a spirited driver. I dno't know what tires you are planning on buying but I run Nitto 555 and am very pleased with them. And btw the 245/40 is the same diameter as the stock setup there should be no change in your speed-o readings.

 

Yes the 245X40's are the perfect upgrade, do it. I have the Bridgestone Potensa RE750. They are rated excellent. Costco save me hundreds.

 

very nice... thanks guys...

actually i am thinking between continental and yokohama. high performance summer conditions.

 

runnin' 40's here as well, auto-xing with them as well.

 

http://www.1010tires.com/tech.asp

lots of cool info here


beers

 

still didn't tell me what's the max width tire you can go with any wheel

 

I believe the difference is .3 of an inch in tire heighth. Just slightly shorter than stock. Should be fine. I'm glad some are running that width, I was thinking of doing the same. Any of you have it lowered with the 245/40/18? Any rub?

 

nope,

it is not the oracle it is just good learning stuff...

beers

 

pm sent.

 

depends on the tire..

i am lowered and dont rub... not even close...

offset is the key...

beers

 

i would love to lower my car's height but the roads in Cyprus even if they are very good they are under constructions most of the times :P

so, its better to keep stock height for the safe of my back and my suspension.

i ve even thought to put 245/45R18 to have a smoother/softer feeling and then lower it with springs so i will stay at the same height but it will look prettier and it will still be smooth.

 

About to put my second set in this size on the stock rims.

 

How could the 245/40 be the same diameter as 225/45 ???

if the 40 and 45 are the aspect ratio ratings (percentage of tire width), then

40% of 245 does not equal 45% of 225????

 

Close enough, same size to a tenth of an inch, wider, cheaper, more widely available, and will actually make the speedo closer to accurate - where is the downside?

Use the calculator, Luke.....

http://www.miata.net/garage/tirecalcold.html

S

 

^ all good points but there are not cheaper. Well the Kumho's are not cheaper. I just bout 4 new tires last week. The 245/40's were $30 MORE per tire than the 225/45's.

 

That's the size on my car. Height difference is negligible - it will increase speedo error by about 1 mph - from the factory, compared to my portable GPS, the factory speedo was off by 1.5 at 60, and when I switched the tires that increased to 2.3 mph error. Other than that, perfect.

I run Pirelli PZeroNero M+S from TireRack. They were great to work with and had an authorized installer local to me. I'm about to order another set in the next week or so.

Stew

 

Lowered with Mazdaspeed. 245/40/18 Bridgestone RE-01R. Fan-f'n-tastic!

 

I'm just amazed no one yelled "use the search button!"

 

naw this guy is really trying to learn.. and does go where pointed...

beers

 

*lol* I was thinking the same thing. We might be entering an era of the kinder/gentler RX-8 Club.

 

Numbers are a little more difficult to search for. 245/40 18, 245/40/18, 245-40-18, etc.

 

i shall allow this thread.

 

wow,

roflmao,,,,,

houston, we dont have a problem...

all is well..

beers