Mixing Tyres/Poor Handling
- Thread starter flimper
- Start date
Mine has been unpleasant since I bought it. I fixed three issues relating to the steering and handling on the front end, as well as having a four wheel alignment, but the front was still nervous on all road types (particularly with changing camber).
I fitted new Toyo Proxes on the rear a few weeks ago but swapped them to the front out of interest...totally different car. The fronts and rears have never been matched on my Z4 in my 10 months of ownership, and they still aren't, but the front tyres were ruining the steering. They had worn with a raised band roughly in the middle of the tread, about 5 mm wide and 1 mm tall, and this band wandered from side to side across the face a little as you rotated the wheel. None of the tyres have been run flats, and all premium brands, but this was my final issue.
I fitted new Toyo Proxes on the rear a few weeks ago but swapped them to the front out of interest...totally different car. The fronts and rears have never been matched on my Z4 in my 10 months of ownership, and they still aren't, but the front tyres were ruining the steering. They had worn with a raised band roughly in the middle of the tread, about 5 mm wide and 1 mm tall, and this band wandered from side to side across the face a little as you rotated the wheel. None of the tyres have been run flats, and all premium brands, but this was my final issue.
Flimper supersports are better in the summer in warmer temps and the dry. Ps4s are better in the wet but marginally worse in dry conditions where you're really loading them up. What you could be experiencing is more understeer and a bit less predictability in the wet/cold weather currently, as you have a more wet/winter optimised tyre at the rear compared to the front.
That being said, I used to run ps4 rear and supersport fronts on my 3.0si with no real issues at all - if you've not done alignment in a while I'd definitely recommend that as a starter!
That being said, I used to run ps4 rear and supersport fronts on my 3.0si with no real issues at all - if you've not done alignment in a while I'd definitely recommend that as a starter!
Just to be clear I'm not suggesting the ps4 is a winter tyre by any stretch - just that the ps4 tyre is supposed to sit below the ps4s, which was supposed to replace the supersport as the summer/sport tyre. The ps4 is supposedly more comparable to the older ps3 which was far more an 'all-rounder' tyre....
@eddoe @MrPT @buzyg Not been pressing on at all, noticing it at a sedate pace, feels like it's tramlining a bit more than normal, nothing serious just slightly irritating and want to get it cleared up for when the weather improves. The rears have not been run in at all yet.
Two things have become clear since running my Z4 and hanging around the forums, these cars are unusually sensitive to changes in tyres/pressures, suspension/bushes, alignment and wear of course.
2nd, sorting it out based on others experience is hit-and-miss. Few cars are alike now, what with swapping from RFT's, wheel size changes, non-OEM springs and bushes, alignment changes and wear, then it's always proven difficult to do anything other than work through the list of possibles.
It took me ages! Replacing a broken rear spring, saggy bushes, new non-RFT tyres, a Hunter 4-wheel alignment and tyre pressures got rid of 80% of the problem, it took 2 alignments with someone who knew what they were doing and was able to take account of changes (rather than sticking to the computer's specs) to finally sort it.
2nd, sorting it out based on others experience is hit-and-miss. Few cars are alike now, what with swapping from RFT's, wheel size changes, non-OEM springs and bushes, alignment changes and wear, then it's always proven difficult to do anything other than work through the list of possibles.
It took me ages! Replacing a broken rear spring, saggy bushes, new non-RFT tyres, a Hunter 4-wheel alignment and tyre pressures got rid of 80% of the problem, it took 2 alignments with someone who knew what they were doing and was able to take account of changes (rather than sticking to the computer's specs) to finally sort it.
Ewazix said:
Can you do my car too? :lol: mines terrible. It actually feels like something is broken! I have been driving in sport mode and that seems to sort it to some extent.
These cars with their electric steering are shockingly bad. At least the M's have proper hydraulic steering.
:driving: I disagree that all our cars are different.
I would certainly get the alignment checked if it hasn't been done for some time.
Bear in mind that if you're running standard camber you'll have worn the rear inside of the main belt more than the outside - your old tyres would therefore have a greater effective contact patch perpendicular to the road. Your new tyres by comparison won't be worn so you'll be running marginally more on the inner edge - making it feel more like it tramlines at the moment.
At the end of the day it can only be worn bushes, alignment or tyre pressures. Which is the same combination as with any other zed (electric steering on the si's notwithstanding).
If the tyres are fresh on I'd get some dry seat time, do a tank of fuel getting them properly scrubbed in and take it from there, but alignment would be the next thing on the list if it were me.
I would certainly get the alignment checked if it hasn't been done for some time.
Bear in mind that if you're running standard camber you'll have worn the rear inside of the main belt more than the outside - your old tyres would therefore have a greater effective contact patch perpendicular to the road. Your new tyres by comparison won't be worn so you'll be running marginally more on the inner edge - making it feel more like it tramlines at the moment.
At the end of the day it can only be worn bushes, alignment or tyre pressures. Which is the same combination as with any other zed (electric steering on the si's notwithstanding).
If the tyres are fresh on I'd get some dry seat time, do a tank of fuel getting them properly scrubbed in and take it from there, but alignment would be the next thing on the list if it were me.
That doesn’t make much sense to me. Also... “twitch” at the front and “flop” at the rear, rounded off with an appraisal of how well they lay down chav tracks?! :lol:
Mismatched sidewall profile front-to-rear (and hence, mismatched sidewall stiffness) is a feature of a lot of cars famous for their handling - 600LT, GT3 RS, Ferrari 488, AMG GT-R etc.
I’d experiment with pressures first.
Mismatched sidewall profile front-to-rear (and hence, mismatched sidewall stiffness) is a feature of a lot of cars famous for their handling - 600LT, GT3 RS, Ferrari 488, AMG GT-R etc.
I’d experiment with pressures first.
Interesting. My PS3's on the front that I binned despite having a good 5mm of tread left had very similar strange wear. The tyres were the source of the tramlining and other issues. I've refreshed everything on the front end and the alignment was fine so I knew in the end it could only be the tyres. I even tried backing the the camber off from maxed out to stock before going to the expense of changing the tyres. I put the strange wear down to the fact that the front end needed a complete overhaul before I did it and the alignment was out from before I got it. I only actually noticed the strange wear once the tyres were off the car and under close inspection.wonkydonkey said:
[ref]MACK[/ref] I'm sure you were kicking yourself as hard as I was when I finally changed the easiest (and arguably most obvious) factor that can affectt steering. I'm also sure you're similarly happy to have a car that holds its line now! 
8)
8)