130i on 17" Runflats
Discussion
Hi,
As I think I mentioned on an earlier thread, I've bought a Japanese import 130i M sport auto. Coming from Japan as it does, it's got 17" wheels on it, from the factory (looks like 18s were only an option over there).
It's wearing 205/50 17 front and 225/45 17 rear. Incredibly, they're still the original tyres from the factory, date stamped 2008, as it's only on 11,000 miles.
As you can imagine, I wanna get em off. But.... I have a dilemma.
Back in 2017, I had a 130i SE, also 17", 205/50 17 front and rear, from the factory. Not liking the wet grip, I ditched the Bridgestone Potenza runflats (probably put on some time around the early 2010s) and got some 'normal' Conti Prem Contact 6. I immediately regretted it. Although they improved wet grip, they also spoilt the handling. I was never quite happy with the handling on that car, no matter what I did. With the runflats, it felt scary in the wet and unpredictable in general. But, when I ditched them, all of a sudden the car had insufficient body control. There was just too much body movement for the car to be sharp like a hot hatch should be.
This time, I've got an M sport with stiffer suspension than my old SE had. With the runflats that it's got on, the handling is fine - I definitely don't want it to be any less sporty than it is now. It's just dangerous on it's current antiquated tyres. Spins its wheels in the dry, and gets sideways in the wet without trying. What I want to achieve is the following:
1. Keep the handling every bit as taut as it is now (old steer was a 987 Boxster)
2. Reduce wheelspin/unwanted oversteer
3. Improve wet grip
4. Not make ride any worse than it is already
Ideally, I'd like to keep my 17" wheels, but I'm open to getting a set of 18s if need be.
I hear runflats have improved some. My question is, would a set of 'normal' tyres on 18" wheels, give handling as taut, less taut or tauter than sticking with my 17s and getting a newer generation of runflats? I don't want to introduce any extra body movement like last time.
Thanks
As I think I mentioned on an earlier thread, I've bought a Japanese import 130i M sport auto. Coming from Japan as it does, it's got 17" wheels on it, from the factory (looks like 18s were only an option over there).
It's wearing 205/50 17 front and 225/45 17 rear. Incredibly, they're still the original tyres from the factory, date stamped 2008, as it's only on 11,000 miles.
As you can imagine, I wanna get em off. But.... I have a dilemma.
Back in 2017, I had a 130i SE, also 17", 205/50 17 front and rear, from the factory. Not liking the wet grip, I ditched the Bridgestone Potenza runflats (probably put on some time around the early 2010s) and got some 'normal' Conti Prem Contact 6. I immediately regretted it. Although they improved wet grip, they also spoilt the handling. I was never quite happy with the handling on that car, no matter what I did. With the runflats, it felt scary in the wet and unpredictable in general. But, when I ditched them, all of a sudden the car had insufficient body control. There was just too much body movement for the car to be sharp like a hot hatch should be.
This time, I've got an M sport with stiffer suspension than my old SE had. With the runflats that it's got on, the handling is fine - I definitely don't want it to be any less sporty than it is now. It's just dangerous on it's current antiquated tyres. Spins its wheels in the dry, and gets sideways in the wet without trying. What I want to achieve is the following:
1. Keep the handling every bit as taut as it is now (old steer was a 987 Boxster)
2. Reduce wheelspin/unwanted oversteer
3. Improve wet grip
4. Not make ride any worse than it is already
Ideally, I'd like to keep my 17" wheels, but I'm open to getting a set of 18s if need be.
I hear runflats have improved some. My question is, would a set of 'normal' tyres on 18" wheels, give handling as taut, less taut or tauter than sticking with my 17s and getting a newer generation of runflats? I don't want to introduce any extra body movement like last time.
Thanks
I’d stay away from runflats personally, but make sure you replace with XL rated tyres. It may be you went too soft on the sidewall last time. Obviously the lower the profile the more you reduce potential sidewall movement, everything else being equal.
Don’t look at comfort oriented tyres but more of a performance tyre. Personally, I’d move up to 18s as this should increase your options.
Stay with a staggered setup if you’re more comfortable losing grip at the front than the rear, but a square set up (with the same size tyres all round, albeit potentially with slightly different rim widths) makes for a sharper steer.
Don’t look at comfort oriented tyres but more of a performance tyre. Personally, I’d move up to 18s as this should increase your options.
Stay with a staggered setup if you’re more comfortable losing grip at the front than the rear, but a square set up (with the same size tyres all round, albeit potentially with slightly different rim widths) makes for a sharper steer.
FWIW ditching the RFTs on my F31 and running 18x8 alloys with 235/45/18 non RFTs (Goodyear Assym 6s) all round has been a very good move… The car drives, handles, turns in better than it did on the staggered 19s with RFTs, it’s comfier and quieter too, and a smoother ride.
And with the full suspension overhaul I’ve just done, it’s even better again (currently on Goodyear all seasons acting as the dedicated winter tyres/wheels etc)
I agree with the above that 18s would be better move, you’ll still have decent sidewall to take the bumps, but less sidewall deflection that can make the handling / steering feel squidgy
And with the full suspension overhaul I’ve just done, it’s even better again (currently on Goodyear all seasons acting as the dedicated winter tyres/wheels etc)
I agree with the above that 18s would be better move, you’ll still have decent sidewall to take the bumps, but less sidewall deflection that can make the handling / steering feel squidgy
I bought a 123d in 2008 and was on my 4th set of Pirelli run-flats when I sold it in 2012. Although they were 205/50 x 17 all round it was on M-Sport suspension and I never had any issues with them in terms of grip or ride quality.
Then I got a Z4 with 18" Bridgestone run-flats and they were horrible!
I've got an E90 330i now that has 225/45 x 17 Continental run-flats and they're pretty good too.
I'd be tempted to try fitting a quality brand of run-flats to your 17" wheels before buying new wheels as well.
Then I got a Z4 with 18" Bridgestone run-flats and they were horrible!
I've got an E90 330i now that has 225/45 x 17 Continental run-flats and they're pretty good too.
I'd be tempted to try fitting a quality brand of run-flats to your 17" wheels before buying new wheels as well.
Mr Tidy said:
I bought a 123d in 2008 and was on my 4th set of Pirelli run-flats when I sold it in 2012. Although they were 205/50 x 17 all round it was on M-Sport suspension and I never had any issues with them in terms of grip or ride quality.
Then I got a Z4 with 18" Bridgestone run-flats and they were horrible!
I've got an E90 330i now that has 225/45 x 17 Continental run-flats and they're pretty good too.
I'd be tempted to try fitting a quality brand of run-flats to your 17" wheels before buying new wheels as well.
The Z4 chassis was based on the E46. The E46 wasn’t designed for run flats. This may explain why you didn’t like them on the Z4. My E91 had Bridgestone runflats when I bought it-I agree, they were awful. Then I got a Z4 with 18" Bridgestone run-flats and they were horrible!
I've got an E90 330i now that has 225/45 x 17 Continental run-flats and they're pretty good too.
I'd be tempted to try fitting a quality brand of run-flats to your 17" wheels before buying new wheels as well.
Mr Tidy said:
I'd be tempted to try fitting a quality brand of run-flats to your 17" wheels before buying new wheels as well.
Yeah, think I'm gonna go that way. PS4 Zero Pressure just happen to be available in both my front and rear small 17" sizes. Word on the street is they're more comfortable than Bridgestone etc. Asymmetric 6 not available in my sizes. So I'm gonna give the PS4s a go. Appreciate all the comments.Personally, I have never looked back after ditching RFTs on my E91. I don't rate Continental, based on personal experience - that last time I had any were on a Clio 197 and they were bloody hopeless (obviously that was years ago though!). And recently I found that F1s have also gone a bit "off" - I found they'd got a bit too soft for my liking. I'm now on PS5 all round and really rate them. A spot on balance of not being too harsh or too soft, and really decent cold and wet grip.
Only bugbear is that they have almost no rim protection, whereas the F1s before had really decent rim protection.
Only bugbear is that they have almost no rim protection, whereas the F1s before had really decent rim protection.
helix402 said:
The Z4 chassis was based on the E46. The E46 wasn’t designed for run flats. This may explain why you didn’t like them on the Z4. My E91 had Bridgestone runflats when I bought it-I agree, they were awful.
I know the E46 never had run-flats as I've had 2. But the E85/86 Z4s had run-flats as standard from new (apart from the M and maybe Alpina) so someone at BMW decided they'd be OK with run-flats!
They don't seem to always design the cars to suit one type of tyre. Mrs Tidy bought a new Mini One in 2003 and had the option of run-flats or normal tyres with a space-saver spare so she chose the latter.
Great question.
I’ve had my 130i about 5 or 6 years and quite soon after I bought it (random tyres, leaky shock, etc) I fitted new Eagle F1 Asym 3 and lots of new suspension bits.
It never truly gelled with me, always felt a bit crap and soft. I was always thinking about new m3 bushes etc.
I only do low miles but finally wore the Asym3 tyres out. They’d clearly gone soft after the Asym1 and 2.
I bought tyres specifically hard with solid shoulders and basically like sports tyres used to be.
The Bridgestone Potenza Sport are so much nicer. The steering is still a bit light (my wife gets arm ache driving it but I think it’s light), but the car is moving with the tiniest of inputs, and the soggy lag as you turn in is much reduced… it’s just sharp and immediate.
Yes it rides a bit harder but not uncomfortably so.
Indeed a fair bit of the time it feels to ride better as it’s just settled rather than flabbing about.
My hypothesis is that BMW set the springs, dampers, bushings, all with a high tyre rate and stiffness in mind.
Going non-rft removes all that tyre rate and makes the cars feel rubbish.
So go with rft or a high tyre rate non-rft tyre.
Original RFT were crap. These days I’d say they’re fine.
Most mainstream sports tyres these days are soggy crap… or expect cars to be setup without a high tyre rate in mind.
I’ve had my 130i about 5 or 6 years and quite soon after I bought it (random tyres, leaky shock, etc) I fitted new Eagle F1 Asym 3 and lots of new suspension bits.
It never truly gelled with me, always felt a bit crap and soft. I was always thinking about new m3 bushes etc.
I only do low miles but finally wore the Asym3 tyres out. They’d clearly gone soft after the Asym1 and 2.
I bought tyres specifically hard with solid shoulders and basically like sports tyres used to be.
The Bridgestone Potenza Sport are so much nicer. The steering is still a bit light (my wife gets arm ache driving it but I think it’s light), but the car is moving with the tiniest of inputs, and the soggy lag as you turn in is much reduced… it’s just sharp and immediate.
Yes it rides a bit harder but not uncomfortably so.
Indeed a fair bit of the time it feels to ride better as it’s just settled rather than flabbing about.
My hypothesis is that BMW set the springs, dampers, bushings, all with a high tyre rate and stiffness in mind.
Going non-rft removes all that tyre rate and makes the cars feel rubbish.
So go with rft or a high tyre rate non-rft tyre.
Original RFT were crap. These days I’d say they’re fine.
Most mainstream sports tyres these days are soggy crap… or expect cars to be setup without a high tyre rate in mind.
Mr Whippy said:
Great question.
My hypothesis is that BMW set the springs, dampers, bushings, all with a high tyre rate and stiffness in mind.
Going non-rft removes all that tyre rate and makes the cars feel rubbish.
That makes sense really, and probably explains why my 123d with M-Sport suspension rode and handled pretty well on Pirelli run-flats.My hypothesis is that BMW set the springs, dampers, bushings, all with a high tyre rate and stiffness in mind.
Going non-rft removes all that tyre rate and makes the cars feel rubbish.
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