Tyre size difference

[jpar196]

Hey all,

Im upgrading from factory size of 205/50/16, to a 225/45/17 and it looks like theres approximately 3.5%

difference in tyre circumference, Is this a big of a deal ?

basically putting V7 wheel/tyres on to a V5 STi. Anybody running this combo ?

[WRXER]

Yeah thats pretty much what I've always driven on lol, never driven on 16s so couldn't comment on difference but I doubt ul find any issues lol

[jpar196]

oh so you run 225/45 profile ? should be sweet then, thanks for that man

[dubbedup]

your allowed 30% differnce in rolling radius? at least that was what the wof guy told me...i got 215/35/19s and get wofs no probs...

[Joker]

Car Calculator V2.1 download HERE!

will help..

[Guest]

 dubbedup said:

your allowed 30% differnce in rolling radius? at least that was what the wof guy told me...i got 215/35/19s and get wofs no probs...

Your speedo is allowed to be 5% out...

I have had issues getting 225s to work on a GC8 so check your wheel offsets

[newsuba]

 jpar196 said:

Hey all,

Im upgrading from factory size of 205/50/16, to a 225/45/17 and it looks like theres approximately 3.5%

difference in tyre circumference, Is this a big of a deal ?

basically putting V7 wheel/tyres on to a V5 STi. Anybody running this combo ?

Was running this combo when I first fitted Subaru BBS 17" wheels to my STi v6.

The wheels came with Goodyear F1 GS-D3's in 225/45-17.

Mechanically, the wheels have the same offset as the factory 16's but the extra width means they will sit closer to the struts.

In practice this shouldn't be a problem.

Anyone with a modicum of driving sensitivity will notice a difference in the car's performance and handling.

Effectively raising the car's overall gearing, responsiveness is dramatically (subject to the calibration of the driver's butt dyno) dulled.

The bigger tyres increase steering weight a bit (good) but tramlining increases.

Also in vigorous driving the tyres will contact the bodywork.

Better to go to 215/40-17 or 215/45-17.

40-series being closer to the original rolling radius.

Unless you want that filled out look, and 225/45-17s do fill the guard nicely.

[Shale]

Never had issues on 215-45R17 which is what's on the GC8 at the moment. 215-40R17 felt a wee bit brutal on Auckland's crap roads.

If you do go 225-45R17 let us know how much the tyres cost per corner, and what make they are!

[jpar196]

just put them on, they rub when I turn hard on a slow medium corner. around faster corners it should be fine,

had the same issues in my last cars, will find out soon enough. I think the 40 profile is more suited for them tbh. They look good tho, and the tyres are re01r bridgestones. Best the money can buy imo before re11s.

They are 2nd hand, but heaps of tread on them

[newsuba]

Damn good tyres !

BS' best road tyre before the RE11.

Funny that they rub when going slow/medium, mine went rub-a-dub when going fast.

[jpar196]

yeah, ive used them before on my civic type R and loved them to bits over any other tires ive used.

It only rubs when I get decent lock and roll, if Im taking corners at about 80~100 I dont get as much lock

and wont rub, but 40~50 kms hard cornering will make it rub. and I definately notice the longer ratio.

takes longer to rev up, not overly fussed with it at the moment, as the cars used primarily on the road, its only in the top rev range that I notice it. hopefully these stand up to some grief Ill be giving them at hamptons

[Shale]

RE01R.... dear god, so much WIN!

[Guest]

I was gonna say that different tyres of the same size are a different shape so some will be more likely to rub then others.

As an example, the RE050's are actually physically narrower at the tread then the Toyo Proxes 4's and the Dunlop DZ101's I've had previously even though they were all 215/45/17's.

Not that it matters as you've done the tyre swap now

[newsuba]

Yep.

The numbers stamped on the side are only nominal, you need to check with the manufacturer for actual measurements.

As well as differences between brands, there are often differences within brands.

Eg, the Toyo T1R 215/45-17 is only 211mm wide, whereas the 215/40-17 is 222mm.

BTW the width number refers to the section width (sidewall to sidewall) not the tread width.

[Guest]

 newsuba said:

BTW the width number refers to the section width (sidewall to sidewall) not the tread width.

Ah, that'd explain it.

[jpar196]

yeah I think its due to the re01r having such wide and solid shoulders compared to tyres with softer side walls,

not that Im complaining about that ;D