245/40 18 vs. 245/45 18 on stockies
 

just as the title says im in need of new tires and i wanna put 245s on my stock rims. ino they will fit but i dont know if i should get 40 or 45s?

245/40 unless you want your speedo to be a little off.

40's are usually way cheaper but knocks your speedometer off a little.

At 100 MPH your speedometer is off by about 3.4 MPH(96.589MPH).

Its no big deal except your odometer will read about 3.4% higher than actual miles on the car. Also it provides more torque than most aftermarket parts!

hmm no big... but just as a side note, if i got an accessport from mm in the future could he correct the speedo?

i say 40's

40, better overall diameter

245 / 45 / 18 = speedometer being 2.7% too slow

245 / 40 / 18 = speedometer only 1% too fast

WHAT!?!

The width 245 does not change yout speedo.

Seems like you been post whoring too much.

What??? a 245/45/18 has a larger overall diameter then 245/40/18. 225/45/18 and 245/40/18 are approximately the same diameter. Go with the stock diameter 245/40/18.

No the AP can not change the speedometer.

yeah.. no, you're wrong. :lol:

other way around..

correct tire diameter is 25.9.

beers :beer:

yet, but what do i know.

beers :beer:

wrong,

and you mention post whoring??? duh..

good job..

beers :beer:

depends upon what tire manufacturer. height is differant.

really,

maybe by .1 of an inch.. and the specs are out there.

beers :beer:

I'm reviving an old thread with the same question really, so as to avoid posting crappy new one.

But I'm more concerned about the look vs price/rid/handling

'cuz discount tire quoted me the 245/45's at $35 less per tire on every tire

any one have an example of how that would look?

Do the measurements, it depends on the brand of tire. The numbers on a tire or more of a general reference than actual specs so two same numbered tire of different brand can have significantly different weights and measurements. I have a chart here somewhere, I looked at the actual spec for specific tires. Go to the tire manufacturers website and look at the spec for the tires you are comparing. I find it hard to believe the price difference is that large between two tires of the same brand.

The price difference is usually from how common the tire size is OE. GM uses 245/45R18 on a bunch of stuff so they can make money on the volume. My old Expedition had a 255/70R16 tire on it and the same one in 265/75 was much cheaper due to being such a common size.

Either way a 245/45 will be taller than what came on the car. It should be okay on the stock wheels but I would avoid it with lower offset wheels for fear of rubbing.

Well a quick search on Discount's website shows the cheapest 245/40-18 is $85.00 and the cheapest 245/45-18 is $124.00 so I'm not sure what exact tire he is looking at and why it's $35.00 cheaper than a properly sized 245/40-18.

9krpm, I appreciate your though help man
Yeah, I was looking at the Falken Ziex's and the FK452's.
I'm actually running the Ziex's on mine now, but they're almost dangerously worn out now. I give 'em a week before the cords show.

If you have any other good price/compromise tire suggestions I am all ears man. Been lurking here for over a year now, and I've certainly come to respect yours and a few other opinions haha

Opinions on tires are largely useless. I run Federal 595SS's and like them a lot (quiet, sticky, and are wearing well) and are as good as the Yokohamas and BFG's I have had in the past. Others will say they are crap and if I tracked a lot on them I might concur. Some of my friends run $1200.00 Michelins and love them, others have had them and don't like them. Some of the more respected brands like Kumho and Hankook were once considered crap, marketing has a lot to do with it.

But at the end of the day just get what you are comfortable with in your price range.

I don't think you will find an example because no-one else is silly enough to fit the wrong size tyre ...........................

other wheels from another thread. I really don't think its all that silly a question...
Yes, i do realize his offset is different than stock

( https://www.rx8club.com/rx-8-parts-s...s-rims-188137/ )thread

"Wrong size" is pretty subjective Brettus :) The only literal wrong size is like 17s on an 18 rim.

Just look at the "aggressive fitment" thread for a list of people silly enough to put on the "wrong size tire" :suspect: