To Mix or not to Mix RFTs??

[RX-78]

Gutted, got a slow puncture on me Z4. How unlucky is that?? Only had the car for 2 months, and my prev Mini also had a puncture after a couple of months.

Got a real predicament if the local tire place cant fix it: All 4 tires are almost new due to AUC replacing them just before I bought the Zed. I want non-RFT but cant afford it right now & couldn't justify throwing away perfectly good tires. But now if I have to replace one tire should I:

a) replace like with like and put crappy bridgestone RFT?
b) replace it with better RFT and use it until all 4 wears out as they'll still be about same wear? But this wil comit me to using RFT for foreseable future
c) replace the punctured one with non-RFT but this has been said to be a bad option in prev threads....
d) go crazy - take it as a message from high above, spend a few hundred squids putting on 4 new non-RFT

p.s. does anyone know a good tire place around Liverpool?

 

[cj10jeeper]

There's more than enough info on tyre threads on here already from Falkens to better RFT's to downsides of mixing, prices, etc.

The cheapest option has to be to fit a single RFT, but frankly I'd go with 4 Falkens and enjoy the better ride, selling he RFT's to offset the costs.

 

[RX-78]

Thanks CJ Read some of the tyre threads and I suppose most will not recommend mixing it. Just cant make my mind up between option A and D...... Wish I had a little more money

I like the option of selling the RFT, only I've got no place to store them (live in a flat) so will more then likely have to ditch them and loose out

 

[hesios]

there was a post regarding using non on the front and rft on the rear
and most of the people replied " don't"
i believe the reason was something like different characteristics

 

[Greeno]

i am sure i will get growled at for this but when it comes to dont mix,

although i have never done it i am a little skeptical about whether joe blogs who enjoys a bit of a spirited drive once in a while would really suffer any adverse effects.

yes, there is the argument of purity from the driving experience of having all four corners the same but unless you are pushing it hard would you really suffer from mixing 2 + 2?

the ride may well be different between RFT's and non RFTs as the harder sidewall will have a difference but Is the percentile difference in grip really so great?

people may well say not too but i have yet to see any hard evidence - the geeky engineer in me says wait to see it.

i'll now go an duck behind the sofa!

 

[vachss]

people may well say not too but i have yet to see any hard evidence - the geeky engineer in me says wait to see it.

Well, this geeky engineer had to see for himself. So when I had a damaged rear RFT I elected to replace both rears with non-RFTs while leaving the stock RFTs on the front. The handling became "interesting" to say the very least. Breaking the rear end free on even mild corners, DSC activation on gentle bends in the road, etc. After some inquiries I found that this was a result of seriously unbalanced for-aft suspension stiffness, with the RFTs forming an effectively stiffer spring rate. Fortunately this effect faded in intensity from outright dangerous to merely annoying after 1000 miles or so, but I would strongly urge other not to make the same mistake. All RFTs or all conventional, but don't mix.

 

[richard100]

Thanks CJ Read some of the tyre threads and I suppose most will not recommend mixing it. Just cant make my mind up between option A and D...... Wish I had a little more money

I like the option of selling the RFT, only I've got no place to store them (live in a flat) so will more then likely have to ditch them and loose out

No don't ditch them. Just put them on ebay - they will sell. Believe it or not there actually is a market for Bridgestone RFT's.

 

[no fit state]

Like I've said oh here many a times I've had no problems with non runflats on the back and runflats on the front. Over a year and still going .... but I'd not think about mixing them across the axle :thumbsdown:

 

[cj10jeeper]

people may well say not too but i have yet to see any hard evidence - the geeky engineer in me says wait to see it.

Well, this geeky engineer had to see for himself. So when I had a damaged rear RFT I elected to replace both rears with non-RFTs while leaving the stock RFTs on the front. The handling became "interesting" to say the very least. Breaking the rear end free on even mild corners, DSC activation on gentle bends in the road, etc. After some inquiries I found that this was a result of seriously unbalanced for-aft suspension stiffness, with the RFTs forming an effectively stiffer spring rate. Fortunately this effect faded in intensity from outright dangerous to merely annoying after 1000 miles or so, but I would strongly urge other not to make the same mistake. All RFTs or all conventional, but don't mix.

Real interesting from a 'geeky engineer' who has personal experience of the experiment of mixing and detrimental effect on handling. My positiopn has always been that for the majority of driving the average driver will not tell the difference but on the limit one end of the car will behave differently and have yo in a ditch/crash. If you display these characteristics during normal driving then it's even worse.

 

[no fit state]

people may well say not too but i have yet to see any hard evidence - the geeky engineer in me says wait to see it.

Well, this geeky engineer had to see for himself. So when I had a damaged rear RFT I elected to replace both rears with non-RFTs while leaving the stock RFTs on the front. The handling became "interesting" to say the very least. Breaking the rear end free on even mild corners, DSC activation on gentle bends in the road, etc. After some inquiries I found that this was a result of seriously unbalanced for-aft suspension stiffness, with the RFTs forming an effectively stiffer spring rate. Fortunately this effect faded in intensity from outright dangerous to merely annoying after 1000 miles or so, but I would strongly urge other not to make the same mistake. All RFTs or all conventional, but don't mix.

Real interesting from a 'geeky engineer' who has personal experience of the experiment of mixing and detrimental effect on handling. My positiopn has always been that for the majority of driving the average driver will not tell the difference but on the limit one end of the car will behave differently and have yo in a ditch/crash. If you display these characteristics during normal driving then it's even worse.

I'm also an Engineer and if you watch F1 you'll see some of my work going round and round...but I'm not geeky

 

[RX-78]

Thanks for all the replies guys. Sounds like safest not to mix and match as I'm not a great driver to begin with

Richard100:
There is some one who would pay money to buy them I imagined BMW bought them cheap in bargain basement because bridgestone couldnt get rid. Still I've got no space to put 3 massive car tires in my flat....

 

[Dreamer]

Sell the old tyres on ebay and get some nonrfts. Surely you know someone who will put them in a garage for a week or two till they sell?

Or try find a single replacement rft tyre on ebay. Even if the tread isn't as deep as you would like it will keep you going until you want to change all 4.

 

[lacroupade]

But if its a slow puncture, the sidewalls won't have been stressed that much unless you've driven them flat, so theres no issue with a straightforward puncture repair? :?

Had on done on mine when it was fairly new and no problem since.

 

[srhutch]

But if its a slow puncture, the sidewalls won't have been stressed that much unless you've driven them flat, so theres no issue with a straightforward puncture repair? :?

Had on done on mine when it was fairly new and no problem since.

i thought the same on my nn runflat, but nail 1" from edge meant not fixable.

BMW dealer has fitted wronf Falken tyre and not 452 as requested. I have refused it and will drive round on it this week until they change for 452 on Thursday.

I dont think it's wise to drive with different tyres on the same axle, esp with the Z4 as the back is so twitchy to begin with, but micing RFT's with non RFT's is an accident waiting to happen if you drive the car as you are meant to.

 

[RX-78]

I think you guys are right. Went to Costco today and was very very tempted by Michellin PS2..... Oooh I wish I hinted it as a Chrinbo pressie :lol:

 

[The Moo]

I have been running with Falkens on the front and Bridgestone runflats on the back for about a month in a range of road and weather conditions and not aware of any adverse effects. In fact the car feels so much better with 50% of the job done, I am really looking forward to getting the rears changed.