going 225 - problems?

[AWDDave]

Hi all,

I'm planning to change my tyres pretty soon on my 3.0specB. Just wondering if anyone has had any experience with fitting 225/40/18 or 225/45/18?

I would prefer to go 225/45/18, as it has a slight larger rolling diameter than 215/45/18, which means my speedo will be a bit more accurate (atm, 100kph is about 96kph).

Experiences I'm looking for are:
- Scrubbing? Any scrubbing, as the tyres will be wider and taller?
- Any major changes to fuel consumption?

Dave

[sundayDriver]

Are you on the stock wheels?

I'm on a set of 18x7.5 with +48 offset running 225/45/18 on the stock GT-B suspension. No problems at all.

[Mystique]

Running 225/45/18 Bridgestone RE001's on stock RB rim with no problems (except they're not as good as the RE050A's)

[AWDDave]

yep, on stock wheels

[swingn]

225/40 as a replacement is no problem at all on standard rims... No rubbing etc etc etc.

I'd say 225/45 would be in a similar boat, but don't know exactly how much higher it'll push your speedo.

Pretty sure CJ posted a rolling radius calculator awhile ago... Might be worth while searching for it before you make the investment

[Adrian2627]

Is this what you mean?

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

[sundayDriver]

Stock wheels means +55 offset, you should be right, unless you get your car slammed.

[Lib 3.0LR]

Try this site, thats what i used and it works OK
I run 225x40x18 no problems Rim STI Enkei
http://www.ajdesigner.com/fl_tire/tire.php

[Adrian2627]

That's a cool one

[senator]

I am running 225 40 r18 on tb sti wheels, I am also running tein s tech springs, and no issues at all…..

Btw I have also towed (550 kg) with same set up and still no issues

Regarding your Speedo, I am not too sure, mine is fitted with "Speedo converter" due to the wheels and tyres fitted so my Speedo is 2 km/h less then my tom tom

[markii]

Running 235/40/18 (Spec B Rims)

No Problems & Speedo is now Accurate.

[Hotwire]

Running 235/40/18 (Spec B Rims)

No Problems & Speedo is now Accurate.

235/40 on a 7" rim?! geez that must have a bit of bulge

I run 225/40/18 on an 18x8 +45 offset rim and I don't scrub .
Dave, obviously your tyre will be 10mm closer to the strut (being stock +55) but I'd say you'll have no worries.

[markii]

Running 235/40/18 (Spec B Rims)

No Problems & Speedo is now Accurate.

235/40 on a 7" rim?! geez that must have a bit of bulge

I run 225/40/18 on an 18x8 +45 offset rim and I don't scrub .
Dave, obviously your tyre will be 10mm closer to the strut (being stock +55) but I'd say you'll have no worries.

Nope, The side wall sits pretty flush to the rim.
Although the the KU31's have a side wall rim protector, the rubber has a lip extruding from it to protect the rim to a degree.

If your Intrested in some pics:

>> My subi flickr link
>> Liberty.asn.au forum topic link

markii