New tires, help with size?

[ThatChevyGuy 5,000+ posts]

My factory tires are 225/60r/16 and they look retarded with the huge profile, im wanting to to switch to a lower profile when i buy new tires. What should i get? 45's?

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[mikey7182 10+ year member]

That is the stock size on the Grand Prix GTP and Regal GSE... I've had both. I went with a 245/50ZR16 and they looked great. Wider stance, didn't rub, fit on the stock width rim, etc. This size is going to be about 1.3cm shorter than stock on the sidewall, but depending on what brand tire you get, it is measured a bit differently (thus why some tires that are the same size look wider/narrower than others). I had Falken Ziex 512s... they were decent but a very soft compound and I burned through them pretty quick. I'd look into some BFG G-Force T/As or something like that.

 

[hoss 5,000+ posts]

sticking with the same rims or getting new rims?

with what you have currently, you have 5.3" of sidewall on each side of the rim. going to a 45 series would give you 3.9" on each side of the sidewall. however, this will mean you are going to lose 2.6" of tire height (1.3" larger wheel gap, 1.3" lower overall stance)

if you do keep the same wheels and go to a lower profile series, beef up the tread width a bit to compensate visually. this will also increase your sidewall size from the numbers above a bit, but visually will offset the wheel gap some.

 

[tRidiot 10+ year member]

this will mean you are going to lose 2.6" of tire height (1.3" larger wheel gap, 1.3" lower overall stance)

Won't this throw off speedometer accuracy quite a bit?

 

[hoss 5,000+ posts]

it would throw it off a bit, probably about 10%. speedos are calibrated t wheel circumference though, not diameter.

any tire size change will affect the speedo accuracy. even tire wear over time minimally affects it.

IIRC a smaller tire would make your speedo read high, so if it says you are going 35, you might actually only be going 30. i might have that backwards though...

 

[mikey7182 10+ year member]

It would throw it off some... Course he could just go with a wider tire but lower profile... not sure what look he is going for though. You have several options:

Same width, lower profile (less height, more wheel gap)

More width, lower profile (about the same height, more tire on the ground)

Larger rims, lower profile tires (more rim, same overall height)

Larger rims, even lower profile tires, wider tires (same as above but wider tread)

 

[ThatChevyGuy 5,000+ posts]

lower profile, more width, might get rims, depends. if i get that $800 back in two months, lol.

 

[mikey7182 10+ year member]

If no rims, get the tires I suggested up top. A lot of Intrigue guys go that route. If getting rims, stick with the 245 width as well, but get lower profile... For Exampe, if you're doing 17s, you could get away with a 245/50R17 on stock springs, but if you lower the car, you'll want to go 245/45R17s. If you go 18s, I had 2" Eibach springs on mine, and fit both 245/45R18s, as well as 245/40R19s. The 19s looked pretty sweet! Just depends on what you're going for though.

 

[ThatChevyGuy 5,000+ posts]

i really need tires bad. Front are starting to seperate, backs are like brand new, bought them all at the same time.

 

[mikey7182 10+ year member]

Ever rotated them? Or gotten an alignment done? Get your alignment checked, move rears to front, replace rears, done deal.

 

[ThatChevyGuy 5,000+ posts]

i want to lower it also, about a 2/3 drop or something.

 

[ThatChevyGuy 5,000+ posts]

my back two tires are the only originals left, i been getting a long on used tires for the front. Never buy douglas tires. ever. I got ripped out of 400 for them.

 

[tRidiot 10+ year member]

it would throw it off a bit, probably about 10%.

10% = a ticket at highway speed

speedos are calibrated t wheel circumference though, not diameter.

Circumference = diameter x ~3.14

My car currently reads quite a bit faster than I'm going (stock tire size, go figure), and I can tell you, it's a PITA.

 

[hoss 5,000+ posts]

i want to lower it also, about a 2/3 drop or something.

do NOT expect that kind of a drop from tires alone... also remember that the smaller profile tire is also going to increase your wheel gap, making the car visually appear to be taller from the side.

10% = a ticket at highway speed.

ive never recieved a ticket for going under the speed limit //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif