Different Tyre Profiles

Antec

New member
So i noticed yesterday that my front tyres were a 50 profile while the back were a 45 profile :thinking:

Now i noticed on an x5 today and a c200 that the front tyres had a higher profile.

What is the reason for this, afaik the higher profile tyres are cheaper and maybe that's why? or it gives a softer ride perhaps?

I would like to put 45 profile on the front, sure it cant to any harm though?

On that note, has anyone got contacts for new tyres?? :rollsmile:
 

Philip Foglar

///Member
Narrow/wides? So the rear tyres would have to have a slightly lower profile due to the increased width. So if you measure the "thickness" of the profile from the rim to the top of the tread it should still be the same front to rear despite the different profiles.

So making the front the same profile as the wider rear you are then making the overall diameter and therefore rolling circumference smaller which can cause problems with the ABS and tyre pressure sensors etc...
 

msm

Well-known member
The profile you're referring to is not an absolute number but a ratio of the tyre width (which is absolute), if that makes sense.

For example, a 225/40/18 tyre has about the same sidewall height as a 255/35/18 tyre even though the profile are 2 different numbers.
 

Philip Foglar

///Member
msm said:
The profile you're referring to is not an absolute number but a ratio of the tyre width (which is absolute), if that makes sense.

For example, a 225/40/18 tyre has about the same sidewall height as a 255/35/18 tyre even though the profile are 2 different numbers.

+1

Explains what I was trying to say a lot better. Exactly - it's an aspect ratio which becomes easily forgotten when simply being referred to as profile.
 

Raybimmer

New member
Different width and profiles are used but they will be matched to a similar diameter for ABS and tyre pressure monitors to work correctly .
This will be seen as say 225/45x17 front and 255/40x17 rear , both are 633 mm in diameter .
 

3V0M-WP

BMW Car Club Member
That's good explainations, there's no simpler way to explain it.

A rim can have different tire sizes fitted to it. For example:.. I have the 7.5J and 8J size 18" rims. The 7.5J can have 205/45, 215/40 or 225/40. The 8J can take 225/40, 235 and 245/35.

The 1st set of tires was 205/45 and 225/40.
2nd set was 225/40 and 245/35.
Now got 225/40 on all 4 rims.
My last 2 sets were STD tires, not runflats
 

Antec

New member
I understand what you are saying, however all 4 my rims have the same width tyres on. All of them are 225. Are the back actually wider than the front then, even though it has a 225 tyre on?

Remember i have the 17inch multispoke rim.
 

Loom

Member
Tyre width: 225 mm
Front: 225 mm x 50% = 112.5 mm sidewall height
Rear: 225 mm x 45% = 101.25 mm sidewall height

so with both front and rear on 17" wheels the overall diameter differs front to rear.
 

abmi0000

///Member
Some people go with a slightly bigger ratio in front for better ride comfort as long at you are not way out from the rear in terms of rolling circumference, it will be ok.

Based on your tyre size, I don't believe that this was the intent. Looks like someone put something they just got to make it easier on their pocket as your profiles are quite big. The scenario above usually comes into play with smaller profile ratios....at least for me that is. I decided to go with 35 profiles on the front even though I could get 30's in the same brand. Didn't want the constant thud when going over bumps.
 

CyberMatix

New member
Antec said:
I understand what you are saying, however all 4 my rims have the same width tyres on. All of them are 225. Are the back actually wider than the front then, even though it has a 225 tyre on?

Remember i have the 17inch multispoke rim.

No, the figure 225 gives the width, so the rears aren't wider than the fronts. The figure 45 or 50 gives the aspect ratio based on the width, that determines the OD (outside diameter).

So your 50 profile tyres have a larger OD than your 45 profile tyres.

So they're bigger, not wider.


 

Antec

New member
Its on a 130i. So i spoke to a few places and they recommend i run 225/45/17 all around.

Prices i got so far is Bridgestone My01 - R1330, Bridgestone potenza R1760, Yokohama (not sure which one) R1399. Hankook v12 R1500 or michelin ps3 R1800 :cry:
 

moranor@axis

///Member
Official Advertiser
put the higher profile at the back and finish them :)

the car will also be a bit more tail happy with the DTC on because the car will think the rears are spinning a little slower than they really are...

i would not change tires over this just use them till they done and get the right size next time :rollsmile:
 

CyberMatix

New member
Antec said:
Its on a 130i. So i spoke to a few places and they recommend i run 225/45/17 all around.

Prices i got so far is Bridgestone My01 - R1330, Bridgestone potenza R1760, Yokohama (not sure which one) R1399. Hankook v12 R1500 or michelin ps3 R1800 :cry:

Try Falkens.

 

Antec

New member
CyberMatix said:
Antec said:
Its on a 130i. So i spoke to a few places and they recommend i run 225/45/17 all around.

Prices i got so far is Bridgestone My01 - R1330, Bridgestone potenza R1760, Yokohama (not sure which one) R1399. Hankook v12 R1500 or michelin ps3 R1800 :cry:

Try Falkens.

Are they any good? who stocks them?

 

CyberMatix

New member
Antec said:
CyberMatix said:
Antec said:
Its on a 130i. So i spoke to a few places and they recommend i run 225/45/17 all around.

Prices i got so far is Bridgestone My01 - R1330, Bridgestone potenza R1760, Yokohama (not sure which one) R1399. Hankook v12 R1500 or michelin ps3 R1800 :cry:

Try Falkens.

Are they any good? who stocks them?

Good value for money IMHO. I got some on my Z.

http://www.falken.co.za/

Many tyre fitment centres - they will first try and sell you something else tho.

Google "falken tyres" on SA pages and you'll find lots.

 

3V0M-WP

BMW Car Club Member
Antec said:
Its on a 130i. So i spoke to a few places and they recommend i run 225/45/17 all around.

Your 17's is a 7J and 7,5J. You can have 205 on the front and 225 on rear
 

Philip Foglar

///Member
msm said:
Philip Foglar said:
Can't go wrong with the Hankooks! :thumbs:

Only issue with Hankooks is the ridiculous markup TWT has on them.

Too much of a good thing, are they slapping larger profits than before - Hankooks were always relatively cheaper than other typical brands. Pity then, same thing as what happened to Yokohama when it was still good and cost effective...
 
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