Mixing run flats with non run flats

[johnnywas]

I know this is a stupid question but on another forum their seem to be some people mixing rft with non rft,wat do you guys think ? stupid or fecking stupid lol

[pilchardthecat]

Fecking stupid IMO. All the BMWs i've had were hyper sensitive to tyres, i would hestitate to mix manufacturers across axles, let alone runflats/non-runflats.

[agent006]

Probably fine for most of the time. Probably fine when you're pushing on a bit, but it's the kind of thing that will turn an "Oh st that was close" moment into a "Blargh, I'm dead" moment though.

[hyperblue]

Stupid. Ditch the run flats and get some proper tyres.

Edited by hyperblue on Tuesday 6th July 23:15

[pilchardthecat]

You'll get premature wear on bushings and other suspension components, and a great deal of under/over steer depending on which axle has the run flats. There is a huge difference in grip and handling characteristics between the two.

[Richard-G]

i did it on my old Z4, when i had a rear puncture. I just drove carefully and nowhere near the edge of quick. It was only for 2 weeks while i was a bit low on funds to get the front two sorted. I didnt die, but then i didnt drive like a willy

[thunderbelmont]

hyperblue said:

Stupid. Ditch the run flats and get some proper tyres.

Edited by hyperblue on Tuesday 6th July 23:15

I find my T5 better on the Goodyear runflats. So ditch the ordinary old technology tyres, ditch the spare, save some weight, go faster!

[kma]

Just the same as mixing different makes of tyre imo, shouldn't be mixed up on the same axle, should be absolutely fine if each axle has matching tyres.

[kma]

pilchardthecat said:

You'll get premature wear on bushings and other suspension components, and a great deal of under/over steer depending on which axle has the run flats. There is a huge difference in grip and handling characteristics between the two.

"a great deal of under/over steer" - I think that may be exagerating things a bit. It also completely depends on which tyres are used, there's probably quite a few combinations where the handling is completely fine. Finding the right combo might be a bit tricky though, as some combinations could result in poor handling.

[Richard-G]

kma said:

pilchardthecat said:

You'll get premature wear on bushings and other suspension components, and a great deal of under/over steer depending on which axle has the run flats. There is a huge difference in grip and handling characteristics between the two.

"a great deal of under/over steer" - I think that may be exagerating things a bit. It also completely depends on which tyres are used, there's probably quite a few combinations where the handling is completely fine. Finding the right combo might be a bit tricky though, as some combinations could result in poor handling.

all combos will result in poor handling due to the large difference in sidewall stiffness and the noticeable difference in unsprung weight. Its a large comprimise but it isnt dangerous

[Mr E Driver]

I bought some winter tyres for 18" wheels and the tyre place couldn't get the same make for all four tyres.
They fitted Pirelli on the front and Kumho on the back and it was only after driving about 5k on them when I took them off I noticed the Pirelli are rft's and the Kumho are proper tyres. Never made any difference to the way the car handled and not really worried they are different. Ins co are not interested either.

[Silent1]

Bloody unsafe IMHO, my experience of runflats would suggest they're shut on anything but a heavy car such as an ovlov estate or something.

[V8A*ndy]

hyperblue said:

Stupid. Ditch the run flats and get some proper tyres.

Edited by hyperblue on Tuesday 6th July 23:15

Stupid yes mixing them but I wouldn't ditch runflats altogether without properly researching this.

Things have changed.

The more modern BMWs ride and handle great on runflats. My Z4 on 19"s and particulary the wifes 1er on 18"s drive fantastic. Infact her 1 series Mnonsense is one of the best handling hatches i've ever driven and the ride is spot on for the firm suspension.

These cars are setup for runflats. Be careful what you change to. The biggest problem with runflats is availability and the only reason I would now be tempted away from them.

[Richard-G]

V8A*ndy said:

hyperblue said:

Stupid. Ditch the run flats and get some proper tyres.

Edited by hyperblue on Tuesday 6th July 23:15

Stupid yes mixing them but I wouldn't ditch runflats altogether without properly researching this.

Things have changed.

The more modern BMWs ride and handle great on runflats. My Z4 on 19"s and particulary the wifes 1er on 18"s drive fantastic. Infact her 1 series Mnonsense is one of the best handling hatches i've ever driven and the ride is spot on for the firm suspension.

These cars are setup for runflats. Be careful what you change to. The biggest problem with runflats is availability and the only reason I would now be tempted away from them.

the issues i have with them are: .A, cost. The 19 inch run flats i need are touching £300 per corner. B, nobody will repair them should you get a puncture, meaning i could puncture a perfectly good one, replace it, puncture it on the way home and i would need to outlay another £300. C, chattery, tramlining and skittish ride. So bad that it cracked countless alloys on my current model of car (not cracked any of mine Yet)

[pilchardthecat]

V8A*ndy said:

hyperblue said:

Stupid. Ditch the run flats and get some proper tyres.

Edited by hyperblue on Tuesday 6th July 23:15

Stupid yes mixing them but I wouldn't ditch runflats altogether without properly researching this.

Things have changed.

The more modern BMWs ride and handle great on runflats. My Z4 on 19"s and particulary the wifes 1er on 18"s drive fantastic. Infact her 1 series Mnonsense is one of the best handling hatches i've ever driven and the ride is spot on for the firm suspension.

These cars are setup for runflats. Be careful what you change to. The biggest problem with runflats is availability and the only reason I would now be tempted away from them.

I have a 1 series Mnonsense and disagree entirely. The ride, handling, grip, turn-in, everything is better with non-runflat tyres. It utterly changes the car so mucch that i would go as far as to say i wouldn't buy another car with runflats, and if i did, i would reduce the price by an amount equal to the cost of 4 ordinary tyres.

There's a reason no M car has ever been made with runflats.

[The Wookie]

pilchardthecat said:

V8A*ndy said:

hyperblue said:

Stupid. Ditch the run flats and get some proper tyres.

Edited by hyperblue on Tuesday 6th July 23:15

Stupid yes mixing them but I wouldn't ditch runflats altogether without properly researching this.

Things have changed.

The more modern BMWs ride and handle great on runflats. My Z4 on 19"s and particulary the wifes 1er on 18"s drive fantastic. Infact her 1 series Mnonsense is one of the best handling hatches i've ever driven and the ride is spot on for the firm suspension.

These cars are setup for runflats. Be careful what you change to. The biggest problem with runflats is availability and the only reason I would now be tempted away from them.

I have a 1 series Mnonsense and disagree entirely. The ride, handling, grip, turn-in, everything is better with non-runflat tyres. It utterly changes the car so mucch that i would go as far as to say i wouldn't buy another car with runflats, and if i did, i would reduce the price by an amount equal to the cost of 4 ordinary tyres.

There's a reason no M car has ever been made with runflats.

Out of interest, what year of 1er do you have? They changed the suspension setup to better accomodate the runflats in about 07

[Snoop Bagg]

I had a slow puncture the other day and was genuinely made up I didn't have run flats on my new Mini. For the last few years of Mini ownership run flats have cost me a fortune with punctures which cannot be repaired despite being a pretty much new tyre. With regular tyres you can unles it's near the side wall or genuinely irrepairable, and it cost around £15 instead of £150!

[pilchardthecat]

The Wookie said:

pilchardthecat said:

V8A*ndy said:

hyperblue said:

Stupid. Ditch the run flats and get some proper tyres.

Edited by hyperblue on Tuesday 6th July 23:15

Stupid yes mixing them but I wouldn't ditch runflats altogether without properly researching this.

Things have changed.

The more modern BMWs ride and handle great on runflats. My Z4 on 19"s and particulary the wifes 1er on 18"s drive fantastic. Infact her 1 series Mnonsense is one of the best handling hatches i've ever driven and the ride is spot on for the firm suspension.

These cars are setup for runflats. Be careful what you change to. The biggest problem with runflats is availability and the only reason I would now be tempted away from them.

I have a 1 series Mnonsense and disagree entirely. The ride, handling, grip, turn-in, everything is better with non-runflat tyres. It utterly changes the car so mucch that i would go as far as to say i wouldn't buy another car with runflats, and if i did, i would reduce the price by an amount equal to the cost of 4 ordinary tyres.

There's a reason no M car has ever been made with runflats.

Out of interest, what year of 1er do you have? They changed the suspension setup to better accomodate the runflats in about 07

Mine's 2008, so one of the newer ones. I actually found the ride etc ok on runflats a bit crashy but not desperately bad, but the traction was poor - the DTC used to come on all the time. It's only when you change to normal tyres that you realise how much better the car is than you think

[The Wookie]

pilchardthecat said:

Mine's 2008, so one of the newer ones. I actually found the ride etc ok on runflats a bit crashy but not desperately bad, but the traction was poor - the DTC used to come on all the time. It's only when you change to normal tyres that you realise how much better the car is than you think

Yeah, I've found the ride in my M-sport shod 3 door fine, but you're right, every time you go over a sharp bump under even slight power in the dry the DTC light starts pounding away.

I was worried about non-runflats needing a setup or losing a bit of response and body control

[pilchardthecat]

The Wookie said:

pilchardthecat said:

Mine's 2008, so one of the newer ones. I actually found the ride etc ok on runflats a bit crashy but not desperately bad, but the traction was poor - the DTC used to come on all the time. It's only when you change to normal tyres that you realise how much better the car is than you think

Yeah, I've found the ride in my M-sport shod 3 door fine, but you're right, every time you go over a sharp bump under even slight power in the dry the DTC light starts pounding away.

I was worried about non-runflats needing a setup or losing a bit of response and body control

Bin them! You'll lose that horrible mid-corner skippyness too.