Z3 tyre sizes ?

[Vaughan]

As I mentioned on other thread I,m currently renovating wheels (17's ) on my Z3.
Bought a set of 16's off ebay to use through winter and whilst I work on the 17's. Tyres are decent condition and are all 225/50/16. The ones removed were 225/45 /17 front and 245/40/17 rear.( normal sizes for 17 inch Z3 I believe)

Traction control light is far more active, especially in wet , ride is more compliant ;pot holes less jarring and car is generally more comfortable. I suppose all this is to be expected ( 50% profile over 40%) will give slightly larger sidewall,..but what has really surprised me is I actually prefer way car now handles. Cant decide wether its my preference or that car does handle better ??? Thinking of trying 205/55 16..
To be honest I,ve always thought Z3 is over tyred. (245 on back of a car weighing circa 1350kg with 200bhp or so seems a bit OTT...yes it looks better but does car really need 245 rear..225 front?? Personally think not ??? Anybody found similar.

Ps. Sidewall depth on 225/50/16 is 98 mm. On 245/40/17 its roughly 112mm. So car will feel more compliant?? Bur better handling ??? I suppose handling is a personal thing ..

 

[Sean d]

As I mentioned on other thread I,m currently renovating wheels (17's ) on my Z3.
Bought a set of 16's off ebay to use through winter and whilst I work on the 17's. Tyres are decent condition and are all 225/50/16. The ones removed were 225/45 /17 front and 245/40/17 rear.( normal sizes for 17 inch Z3 I believe)

Traction control light is far more active, especially in wet , ride is more compliant ;pot holes less jarring and car is generally more comfortable. I suppose all this is to be expected ( 50% profile over 40%) will give slightly larger sidewall,..but what has really surprised me is I actually prefer way car now handles. Cant decide wether its my preference or that car does handle better ??? Thinking of trying 205/55 16..
To be honest I,ve always thought Z3 is over tyred. (245 on back of a car weighing circa 1350kg with 200bhp or so seems a bit OTT...yes it looks better but does car really need 245 rear..225 front?? Personally think not ??? Anybody found similar.

Ps. Sidewall depth on 225/50/16 is 98 mm. On 245/40/17 its roughly 112mm. So car will feel more compliant?? Bur better handling ??? I suppose handling is a personal thing ..

I have to admit that mine was far more comfortable and handled better on the 16s with oem tyre size, it is now on staggard 18s with 35/ 255 on the rear and 225/40 on the front, I feel I have way to much grip on the rear now and get under steer,

 

[Vaughan]

Yep, when I first bought mine I thought steering felt a bit " numb". Pilots helped a lot but wondering if going thinner would improve it more.( two of my 16's are ready for changing, could put 225/50 16 on rear and 205/55 /16 front..all rolling diameters should be about same.. Car does look way better on fat tyres but I,ve been shocked how much nicer mine feels on 16's..I,m sure I,d be quicker in it now...

 

[Sean d]

Yep, when I first bought mine I thought steering felt a bit " numb". Pilots helped a lot but wondering if going thinner would improve it more.( two of my 16's are ready for changing, could put 225/50 16 on rear and 205/55 /16 front..all rolling diameters should be about same.. Car does look way better on fat tyres but I,ve been shocked how much nicer mine feels on 16's..I,m sure I,d be quicker in it now...

I was a lot quicker on the 16s and felt really confident with them.

 

[Vaughan]

Think I,ll get 17's refurbished but spend money on good tyres for 16,'s.. Keep 17's for if ever I sell it.. Does look way better on 17's tho... Nice quandary to have . .

 

[andyglym]

Had many on here say the same about the tyres and how it effects the drive etc if you go large. Sounds logical but I just couldn't part with my MV3's and large tyres even if the drive is a tad compromised, just love the look. Bit of a plodder to take in the views round the twisty stuff if I'm honest.

 

[Sean d]

Had many on here say the same about the tyres and how it effects the drive etc if you go large. Sounds logical but I just couldn't part with my MV3's and large tyres even if the drive is a tad compromised, just love the look. Bit of a plodder to take in the views round the twisty stuff if I'm honest.

Me too pal, could never go back, I just love the look of them

 

[Vaughan]

Fair comments...I,d suspect ultimate grip and lowest lap times would be with fattest tyres you can get under arches...
but how car feels is always a personal thing .
I,d guess it might even be generational...I remember fitting what was viewed as wide tyres on an MG Midget ...around 1974 ??? They were 185/60/13,s...dad said it would ruin feel of car...

 

[oldcarman]

I run four 225/45's on 17" but have a set of 15" which I want to put WWW tires on. Have a pretty good stock ride now but think it will improve as well as give the car a different look! Liked the way @ David did his former car so will go that direction! Would love a set of wire knock offs but $$$$ if you can find them. Daytona make a set but don't really like the style. If you like the 16" why not stay with them. The only person you need to please is yourself so go for it and please post pics! JIM.

 

[ZTec]

I run 225/40/18 on the front with 255/35/18 on the rear, switched from the standard 225's 16" all round after trying @miller1098 wheels on mine, big difference, much better. Then my Zed visited @Lee Zed shed and had new OEM schocks with lowered Eibach springs all round. All the bushes have been changed, now the car drives like new and I have more confidence when having fun. And it looks great, well I think so anyway.

 

[steveyorks]

Given the experience you have you can possibly relate to the disaster BMW created when they put run flat tyres on the Z4. They have an even stiffer sidewall and from my experience ruined the car. It made such a difference when I swapped to normal tyres, totally transformed it.

 

[Eddie Zedder]

It also depends on the wheel width to what tyres are best fit. If your 16" are
7J - 205 or 215 ideal, 195 min or 225 max.
7.5J - 215 or 225 ideal, 205 min, 235 max.
8J - 225 or 235 ideal, 215 min, 245 max.

More can be found here -

http://www.tyresizecalculator.com/tyre-wheel-calculators/tyre-size-for-rim-size-width-calculator

 

[Faheem]

@Sean d I've got oem 16s and I don't feel comfortable or confident in them.

To be honest the rear tyres on my zed have been on there for the best part of 8 years and whilst they've still got tread left on them - plenty of it - the back end will go if youre doing any more than 2000 rpm when it's wet. I don't know whether or not that's normal. This is great for people that know how to control the car, I don't...

 

[Eddie Zedder]

the back end will go if youre doing any more than 2000 rpm when it's wet. I don't know whether or not that's normal.

Ahh, you have discovered the pleasure of rear wheel drive. Wait until we get some ice on the roads!

 

[Mike Trident]

To be honest the rear tyres on my zed have been on there for the best part of 8 years and whilst they've still got tread left on them - plenty of it - the back end will go if youre doing any more than 2000 rpm when it's wet. I don't know whether or not that's normal. This is great for people that know how to control the car, I don't...

I must be driving way too sedately lol, I cant break traction in mine

 

[andyglym]

@Sean d I've got oem 16s and I don't feel comfortable or confident in them.

To be honest the rear tyres on my zed have been on there for the best part of 8 years and whilst they've still got tread left on them - plenty of it - the back end will go if youre doing any more than 2000 rpm when it's wet. I don't know whether or not that's normal. This is great for people that know how to control the car, I don't...

@Faheem tyres have a maximum life of 10 years used or not and ideally should be changed after 6 years say tyre manufacturers on various interweb tyre sites as the chemical composition breaks down over time as well as being hammered by UV etc. Or it just could be that your clogging it everywhere

 

[Vaughan]

I didn't notice things were as bad as in Faheem's case but I did have two thoughts when I changed to 16's. Firstly that traction control was flickering far more and secondly " watch out on roundabouts". Neither thought have previously crossed my mind in the Z.. Back end was definitely " squirmier". Think a combination of narrower tyres, less tread ,cheaper tyres and probably hardened with age....but after a thousand miles or so I definitely prefer it...
A few years ago we got caught out in Derbyshire in a snow storm. Initially everything was passing us, I was thinking how bad car was on snow.. It got so bad everything came to a standstill..except us and a land rover I was following. The look on folks faces as I repast them going up hills on fully opposite lock, tail sat out perpendicular to direction of travel at about 5 mph with wife smiling,hood down ofcourse , was amazing..ended up enjoying ride home...without traction control !!! Car was so slow but almost unstoppable. That's LSD and fat tyres with minimum pressure for you. OT I suppose..

 

[Faheem]

I lent my zed to my dad for a few days last week and he found that the car loses traction easily as well.

Now he drove an E36 for 13 years or so, never had the rear end lose traction and he's the sort of person that'll always do 10mph less than the speed limit.

This proves it is not my driving that's at fault.

 

[Vaughan]

Does your car have traction control Faheem? If I does is it working ?? Mine only gives a slight squirm, light flickers, and security returns..

 

[Lee]

I lent my zed to my dad for a few days last week and he found that the car loses traction easily as well.

Now he drove an E36 for 13 years or so, never had the rear end lose traction and he's the sort of person that'll always do 10mph less than the speed limit.

This proves it is not my driving that's at fault.

This is a common sign the rear bushes are getting very soft. As you corner they flex making the tyres tilt and loose full contact. This disappears once those main beam bushes have bee changed.