Hello folks ! i need some advice on tyre sizes please ! i just got a new set of 17" rims for my sti and was wanting to know can i change my tyre size from 215 45 r17 to 225 45 r17 without having any problems or what size would you,s recommend ?
cherrs folks

 

Dont think you will have any fitment problems persay But as you prob know the wider you go the less grip/traction you will have. Personally i stick to 215's

 

Difference in Diameter: percentage = 1.44 % actual = 9mm

 

I'd also like to know if a 225 will be okay on a 17 x 7J rim, without rubbing the arches? If it did rub, then would a simple roll or the arches' return lip be sufficient to stop it from happening? Better mention my Classic is lowered by no more than 1.5".

Sorry big-kev for coming in on your thread like this, but hopefully I've only added to the info you're seeking an anwer to?

 

Why less grip?

 

My mate had 225 tyres
in his scooby it was a sport with a
turbo engine in it don't know if the setup is the
same but that caught on the back arches from time to time and am sure it wasn't lowered, also going wider with your tyres will
slow you down more too lol

 

If a Classic, then closest 17" to OEM rolling circumference is the 215/40 R17 at 1910mm (OEM, for reference, is 1906mm for 205/55 R15... or 1922mm for 205/50 R16).

A 225/45 R17 gives an RC of 1993mm, at least some 71mm/2.8"!! more travel for every full revolution of the wheels. The speedo will overread big time! (good for 'policing' your speed though ).

 

How will it slow him down?

 

Because for a given aspect ratio, going wider increases the rolling radius....

Hence slower acceleration, and lower speedo reading at a given speed.

HTH

dunx

 

Simple physics mate, more surface area in contact with the tarmac speading the weight

 

A greater RR than OEM means more distance travelled for every wheel rev, so the speedo willl indicate a higher reading! (than the actual speed the car's travelling).

 

I have an 03 WRX with OEM 17" wheels. I went from 215/45/17 to 225/45/17.
There is no difference to clearance on anything.
There is no noticable difference to the speedo either. I have the Road Angel Connected GPS for the speed and nothing changed worth worrying about.
a 17 by 7j rim will take the width with no issues at all.

 

Simple maybe
But the surface area will be the same no mater what size tyres
surface area- Pressure=weight/area.

Unless you add weight or lose from car

the difference in the two tyres is 9mm is that anything to worry about? (don't think so)

 

I have 215/45 17s on and the wheels are describing a distance of some 59mm/2.3" further for every wheel rev, compard to te OEM's 205/55 15s.

Therefore my speedo overeads by about 3% e.g. when doing a true 70mph, speedo theoritcally should be showing 72... but due to the deliberate overread engineered into it by the manufacturer, then it prob reads about 75-78mph, when added to the wheel size's own error!

 

That's right 3.1% more (5.5cm more)
but that's not the size tyres that Big-Kev asked about
his will be 1.4% more so at 30 mph he will be doing 30.4 mph

 

Yeah I know - just illustrating my particular 'real life' experience. It all helps...

 

Compared to what he has on at the mo, yes.

But if he's got a Classic (but who knows what cat he has? - he hasn't posted) then even his existing 215/45 R 17s [what I have too] would be overeading by a fair chunk, when compared to either of the OEM fitments (see post # 7 for an explaination...)

 

no worries bud lol !!! the more info the better

 

sorry i shud of said the car is an 03 sti with standard sizes rims

 

Ahhh, the plot thickens. Kev what is the std tyre sizefor an '03 STi? Is IT 215/45 R17 then?

If so, then yeah, don't have to worry about the 225/45's being 'too big' as far as overeading is concerned (as pointed out in adddison's post #15 ). Just need to know bout the rubbing issue (if there is one)......

 

yip it is 215 45 r17 & thanks eveyone for all the info NOW WHICH IS THE BEST MID RANGED TRYE TO BUY

 

This may be of help https://www.scoobynet.com/wheels-tyr...st-scooby.html

 

Mid range, value for money would prob be Toyo T1-R

Going up a few notches in performance/cost - but still a keen price regardless! - would be the premium Vredestein Ultrac Sessanta...

Or for more cost, then Goodyear Eagle F1 Asymmetric or the really expensive Michelin Pilot Exaltos.

Eveyone has their faves - check Camskill for like-for-like prices...