Tyre size question

[bombur]

Hi all, Just noticed on my 2002 1.9 Z3 that the tyre sizes are front 215/55 16 and rear 225/50 16. Is this a normal set up? Ive had a search online and cant find much. Have no issues with steering or the general drive so its just a general question as I haven't had a car with this difference before.

 

[hard top]

I never did this with the Z3 but I did have have it on Mercedes I have owned and honestly never found it to be a problem.

 

[bombur]

I never did this with the Z3 but I did have have it on Mercedes I have owned and honestly never found it to be a problem.

So next question is - why would you do this?

 

[hard top]

So next question is - why would you do this?

In all honesty, that was the set up on the cars when I bought them.

 

[IainP]

On the size/pressure label there are a variety of sizes.
It may be the previous owner simply couldn’t find 225’s at the time, or needs must because of a puncture.
Or the previous tyres were rubbish in the wet, or snow. Going down a size increases the ground pressure, decreases the contact patch and ‘can’ increase grip on the wet or snow. Though going to an all weather/more treaded pattern does exactly the same thing.
It’s an approved size. I’m running 225’s on the front and 245’s on the back.

 

[bombur]

On the size/pressure label there are a variety of sizes.
It may be the previous owner simply couldn’t find 225’s at the time, or needs must because of a puncture.
Or the previous tyres were rubbish in the wet, or snow. Going down a size increases the ground pressure, decreases the contact patch and ‘can’ increase grip on the wet or snow. Though going to an all weather/more treaded pattern does exactly the same thing.
It’s an approved size. I’m running 225’s on the front and 245’s on the back.

Thanks for this info

 

[the Nefyn cat]

Didn't know there were staggered fittings in 16s. Guess I just learned something today.

 

[NZ00Z3]

I've seen Z3's with 205's and 215's with side profiles to bring the rolling radius up to the normal value. Usually done because of the cost and increasing rareity of the high performance 225/50/16 tyres. Going to smaller width tyres gives you more choice of performance tyres for cheaper prices.

 

[Dakar Z3]

Hello,
from memory your 16” wheels will be 7”x16” all round, the correct tyre size for these wheels should be 205/55/16 all round, however some drivers change the tyre size to give the impression that the rear 16” wheels are wider when in fact they are not, putting a 205 or 215 on the front and a 225 on the rear would give the impression of a slightly wider rear wheel.
Many Z’s are fitted with 17” or even 18” wheels, some even bigger, that’s down to personal choice, however for your question we will stick with the most common sizes.
The popular choice for a Z driver is to have staggered wheels, examples below
front and rear 16” wheels are 7”x16” all round fitted with 205/55/16 tyres

Front 17” wheels are normally 7.5”x17” fitted with 225/45/17 tyres
Rear 17” wheels are normally 8.5”x17” fitted with 245/40/17 tyres
Front 18” wheels are normally 8”x18” fitted with 225/40/18 tyres
Rear 18” wheels are normally 8.5x18” fitted with 255/35/18 tyres

Over the years I have sold 100’s of Genuine BMW wheels so the information supplied should be correct, however please correct me if I have made a mistake.
Please note these are the recommended tyre sizes for the wheels for both Z3 and Z4, however personal choice may vary.

I hope this helps……..

 

[Dakar Z3]

Didn't know there were staggered fittings in 16s. Guess I just learned something today.

Genuine BMW 16” wheels are not staggered.

 

[bombur]

Thanks all for the comments. All my tyres are new/nearly new when I bought so will keep as is. As long as its not dangerous, illegal or impacting driving then I'm a happy chap

 

[Dakar Z3]

Thanks all for the comments. All my tyres are new/nearly new when I bought so will keep as is. As long as its not dangerous, illegal or impacting driving then I'm a happy chap

Hello Bombur,
the tyres on your car are not dangerous, as long as the tyres on the same axle are the same size you are legal.

 

[Phil Dutton]

This topic has come at just the right time fo me. After my MoT in March (1999 Z3 2.8 with 42504 miles) it was pointed out that my front tyres, although legal, have slight cracking on the edge of the tread. I have checked the size of the tyres with a view to changing the front two tyres. I have Michelin Primacy HP size 255 50R16 92W all round. I have for the first time read about DOT Codes, I will come back to this. The small amount of time I have searched this evening they are not easy to match up. I have now looked at the DOT Code on the Tyres to find the last four numbers on the front are 3801 meaning they were made in week 38 year 01. The rear DOT Code is 4810 so made in week 48 year 10. I am therefore driving on 20 year old front tyres with 4mm tread and 11 year old rear tyres with 6mm tread. This raises a few questions. What is the life of a tyre regardless of the tread depth? Should I be changing all four tyres? If I am changing all four what tyres should I go for? My 'boy racer' days are long behind me but I will want a good quality all rounder and expect to pay about £120 per tyre. Advice greatly appreciated.

 

[Dakar Z3]

This topic has come at just the right time fo me. After my MoT in March (1999 Z3 2.8 with 42504 miles) it was pointed out that my front tyres, although legal, have slight cracking on the edge of the tread. I have checked the size of the tyres with a view to changing the front two tyres. I have Michelin Primacy HP size 255 50R16 92W all round. I have for the first time read about DOT Codes, I will come back to this. The small amount of time I have searched this evening they are not easy to match up. I have now looked at the DOT Code on the Tyres to find the last four numbers on the front are 3801 meaning they were made in week 38 year 01. The rear DOT Code is 4810 so made in week 48 year 10. I am therefore driving on 20 year old front tyres with 4mm tread and 11 year old rear tyres with 6mm tread. This raises a few questions. What is the life of a tyre regardless of the tread depth? Should I be changing all four tyres? If I am changing all four what tyres should I go for? My 'boy racer' days are long behind me but I will want a good quality all rounder and expect to pay about £120 per tyre. Advice greatly appreciated.

Hello Phil,

Hello Phil I want you to check, are you sure you have 255 50 16 tyres all round?

sorry but this is a really odd size to have on a Z.

I would think you are probably safe with good quality branded tyres up to 10 years old, but wouldn’t recommend them.
I’m sure I read somewhere that they were thinking of introducing some legislation limiting tyres to a maximum of 5 years old, however I think that would be a long way off yet.
Everyone has their favourites and I am sure you will get a lot of friendly advice from members who have had different experiences, many people buy tyres for the tread pattern (I’ve been there myself),
My choice would be Michelin Pilot Sport 3 or 4 at the top end of the price scale, Uniroyal Rainsport 5 as a mid range with Avon ZV7 at the cheaper end of the Premium Brand.
All three mentioned brands will give you excellent wet grip, (needed for a Z), Michelin and Uniroyal will give you good fuel economy, Avon are not so good on some tyre sizes.

You will have a huge choice of tyres for 205/55/16, 225/50/16 I think will be considerably less, it’s a bit of a dated tyre size.

So there’s a little bit of extra info just to confuse you a little more
Good luck in your search.

 

[Phil Dutton]

Well spotted, dyslexia rules at this end. The Tyres are 225 50 R16.

 

[Dakar Z3]

Well spotted, dyslexia rules at this end. The Tyres are 225 50 R16.

Just noticed you have a 2.8, I’d recommend you put 225/50/16 on a 2.8!

just checked Demon tweaks on eBay, Uniroyal 225/50/16 set of 4 £322 delivered, budget around £50-60 to have them fitted or try your local tyre supplier for supply and fit, please note this is only a ‘suggestion’.

 

[NZ00Z3]

The UK has a ban on 10 year old tires fitted to the front axels on heavy traffic, bus and mini buses (9-16 passengers). https://movingon.blog.gov.uk/2020/1...rs-old-for-heavy-vehicles-and-some-minibuses/

Interesting Edmonds article (USA focus). Use manufacturers recommendations, ranges from 6 to 10 years. https://www.edmunds.com/car-maintenance/how-old-and-dangerous-are-your-tires.html

I've had 12 year old Michelin's on a Z3 give me problems, flat spots and wobbles that don't go away until the tyres are really hot, as in after a 30 mile romp at 60 mile/hr. Got rid of them with 1/4 thread still on them. I now make sure my tyres are not more than 10 years old.

Currently running on my Z3's:

• Michelin Pilot Sport 3, 225/50/16. Came with 8mm thread when new and have a 300 thread wear rating. Top of the line expensive.
• Goodyear Eagle F1 Directional 5, 225/50/16. Came with 10mm thread when new and have a 300 thread wear rating. Getting a whole lot more wear out of these tyres compared to the Michelin's. Cheaper than the Michelin's and just as good for the spirted driving I do, some of it in the wet.

 

[Phil Dutton]

Just noticed you have a 2.8, I’d recommend you put 225/50/16 on a 2.8!

just checked Demon tweaks on eBay, Uniroyal 225/50/16 set of 4 £322 delivered, budget around £50-60 to have them fitted or try your local tyre supplier for supply and fit, please note this is only a ‘suggestion’.

Dakar, thanks very much for the detailed reply and advice. Phil.

 

[Phil Dutton]

The UK has a ban on 10 year old tires fitted to the front axels on heavy traffic, bus and mini buses (9-16 passengers). https://movingon.blog.gov.uk/2020/1...rs-old-for-heavy-vehicles-and-some-minibuses/

Interesting Edmonds article (USA focus). Use manufacturers recommendations, ranges from 6 to 10 years. https://www.edmunds.com/car-maintenance/how-old-and-dangerous-are-your-tires.html

I've had 12 year old Michelin's on a Z3 give me problems, flat spots and wobbles that don't go away until the tyres are really hot, as in after a 30 mile romp at 60 mile/hr. Got rid of them with 1/4 thread still on them. I now make sure my tyres are not more than 10 years old.

Currently running on my Z3's:

• Michelin Pilot Sport 3, 225/50/16. Came with 8mm thread when new and have a 300 thread wear rating. Top of the line expensive.
• Goodyear Eagle F1 Directional 5, 225/50/16. Came with 10mm thread when new and have a 300 thread wear rating. Getting a whole lot more wear out of these tyres compared to the Michelin's. Cheaper than the Michelin's and just as good for the spirted driving I do, some of it in the wet.

Thanks, I will get some prices based on your suggestions. Phil.

 

[Phil Dutton]

Had some good advice already and thank members for their time. The Edmonds article from NZ0Z3 is very interesting and should be noted by those that have the 'weekend car' and consequently do very few miles each year.