New tires - size up!
 

I went into to RADIAL TIRES of SACRAMENTO this morning after researching sizes this past weekend.

Background:
THe 02 Q45 Sport came from the factory w/245/45/18 (26.5 inch diameter)on 18x7.5 alloy rims.
At 60k miles I went to a 255/45/18 (27.0" diameter)

The base of the Strut tower on the front is the limiting factor to how tall a tire can be without using 30mm spacers( BAD:eek:)
http://i678.photobucket.com/albums/v...5clearance.jpg

We tried a 245/50/18 and there is an 1/8 inch gap!!!

THe diameter is 27.7 inches.
The tire weighs 31lb and the current size weighs 30 lbs.

They ordered them today and will install tomorrow.

You could cut off the spring platform and fit threaded sleeves so you can fit 2.5" diameter springs:D

Got the tires on today.
new 245/50/18 27.7" dia. at 55mph 1625rpms
old 255/45/18 27.0 dia at 55 mph 1725rpms

will do mpg runs in a day or so.

as you can see there is no more room!!!

talkhttp://i678.photobucket.com/albums/v...PG/tiregap.jpg about cutting it close!!!

...do you think there's "contact" when driving at high speeds and centrifugal forces are attempting to "enlarge" the wheel diameter?

If you install coilover suspension you dont need so big spacers to get more room. Or change you ET on your wheels.

Well, it's been a month. Had a round trip from Sacramento to LA.....450 miles each way.
No problem with any rubbing.

I had some obdII codes that I had to resolve. And am still addressing some ecu issues pior to my TTT (trip to texas) on Oct 12.

But I just ran a brief highway run.

At 63mph 1775rpms got 30.9mpg (didnot have the grill block or the front underbelly panel in place)

epa is 22mpg highway.

...cars need an "electronic" wheel diameter compensation "box" to allow for use of different diameter wheels & tires!

somebody was posting that in europe it's illegal to go up or down in size........
I run a garmin gps on the dash right above the scangauge, so it gives the correct speed.
That way I don't tie up one of the 4 displays on the scangauge.

Why would I want to ruin the electronic suspenion........:confused: