Amateur Question About Tyres

[bondyshambles 23 1 Cars]

Hi....I have a 1.9 205 phase 1.5 on a 90 plate. The spec for the tyres size is 185 55 15. The tyres on my car are this size. All i hear about on this forum is about tyres that are 195's. Just wandering will they drop straight onto my Speedlines and what effect do they have on the car as in handling speedo readings ? Can you go 195's on the back and 185's on the front ? Is it just Phase 2's that have 195's or am i talking out of my rear ? I have looked through the threads and can't seem to find the answer i need. I ask these questions as i have had 2 new tyres on the front but not yet replaced the rear. Not long had the rear beam done and it does still feel slightly skittish from the rear.

 

Cheers for reading.

[Baz 421]

185/55 is the original tyre size, but less are available these days and they're more expensive, hence most choose195/50's that will fit straight on, wide range of brands available and they're a common size, so cheaper.

[welshpug 1,657]

all 205 gti's should be on a 185 tyre, however purely because of the lower cost do people fit the wrong size, in reality the slightly lower overall circumference doesn't do a great deal of difference to the speedo reading, given the extra width dropping to a 50% profile means the sidewall is very close in height.

 

good example of differing costs, the well favoured Michelin PE2 from Mytyres.co.uk is currently £80 delivered in a 185 55 15, whereas a 195 50 15" is £57 , that is for both tyres in an 82 V weight+speed rating.

 

on these tyre sizes the weight rating does not differ that greatly if at all, however on many larger vehicles if you use a 195 50 instead of say a 195 55 the weight rating will be incorrect.

 

you can use differing tyres front to rear but as they are not the standard fitment you MAY get an advisory, IF the tester notices (I did one year as I had fitted the correct size to the rear but not the front, to counteract the very wayward nature due to some very old and very hard firestones.)

 

obviously it is a big nono to mix them on the same axle however close the overall circumference is.

[bondyshambles 23 1 Cars]

I have just shelled out 200 holes on the standard tyres so this makes sense. Will there be a massive difference if the tyres are mixed in size from front to rear. Or is this just bad practice etc ?

[bondyshambles 23 1 Cars]

all 205 gti's should be on a 185 tyre, however purely because of the lower cost do people fit the wrong size, in reality the slightly lower overall circumference doesn't do a great deal of difference to the speedo reading, given the extra width dropping to a 50% profile means the sidewall is very close in height.

 

good example of differing costs, the well favoured Michelin PE2 from Mytyres.co.uk is currently £80 delivered in a 185 55 15, whereas a 195 50 15" is £57 , that is for both tyres in an 82 V weight+speed rating.

 

on these tyre sizes the weight rating does not differ that greatly if at all, however on many larger vehicles if you use a 195 50 instead of say a 195 55 the weight rating will be incorrect.

 

you can use differing tyres front to rear but as they are not the standard fitment you MAY get an advisory, IF the tester notices (I did one year as I had fitted the correct size to the rear but not the front, to counteract the very wayward nature due to some very old and very hard firestones.)

 

obviously it is a big nono to mix them on the same axle however close the overall circumference is.

 

 

 

You say MAY get an advisory....is this mix from front to back legal ?

[welshpug 1,657]

It is legal yes, but due to not being standard fit like it you may be advised as mentioned, many cars out there use differing front to rear widths and profiles, typically larger RWD sports orinetated vehicles

[Anthony 1,003]

Personally, if you've just put new 185's on the front, I would fit matching 185's to the back to keep the car balanced.

 

As the tyres wear, cycle them front to back so that they all wear at a similar rate, and then since you'll need a full set it's simple to swap to 195's if you choose.

[bondyshambles 23 1 Cars]

Just another reason why i love this forum....thanks for all the help....should have asked this question before i got hammered on them front tyres though !

[johnnyboy666 195 1 Cars]

interesting that you could get an advisory for different sized tyres front to back, I've had my car MOT'd recently with 15inch alloys on the back and 13inch steelies on the front, and that wasnt an issue.

[MiniGibbo 142]

I see no issues running staggered tyres.. Most cars do.

 

What spins me out is the way some of the merc's run different size rims ie 19" front 20" back :/

[welshpug 1,657]

lotus have done that for years.

[MiniGibbo 142]

Weird how it dosent throw everything out though don't you think....

[Baz 421]

No.

[McDude 33]

New RS3 has smaller rears than fronts to balance the car. Looks VERY odd. But as others have mentioned the other way round i.e. bigger rears, is very normal.

 

I wouldn't do it to a 205 though as this has been designed from the outset to have same tyres all round.

[Baz 421]

New RS3 has smaller rears than fronts to balance the car. Looks VERY odd. But as others have mentioned the other way round i.e. bigger rears, is very normal.

 

 

It only has slightly wider section tyres doesn't it? The diameter is the same, 19" iirc.

[McDude 33]

It only has slightly wider section tyres doesn't it? The diameter is the same, 19" iirc.

Correct - yes rim diameter is the same, but fronts wider than rears.

[Mac Crash 78 1 Cars]

can I run a standard 1.9 GTi on factory SMR'S/Speedlines with 195/55/15 tyres?

 

will the 55% profile and extra width over the standard/OE 185 cause fouling on the rear arches or reduced steering lock?

 

thanks, really need to know...

[Tom Fenton 1,542]

It varies car to car, some 205's will be ok, others will foul, usually the rear valance is the first place to rub.

[Mac Crash 78 1 Cars]

Thanks, appreciate that. Would have preferred the 185's but needed to know if I can use what I have before mounting the tyres.