[EthanEJC]

Originally Posted by AndroidRobot

I know but it may get more techy with screens which is what I was referring to via idrive 7 no more analog dials sadly

Just look at the new 2 series grand coupe, looks like the 1 series and the interior will most likely be the same. I'd welcome Idrive7 and a digital dash.

[aerokubectl]

Originally Posted by AndroidRobot

yep, even newer RFTs suck. no BMW should use them or luxury vehicle for that matter

Debatable, but I do agree RFTs have too many compromises.

That said the reason they even exist is because of companies like BMW pushing for them. A spare weighs more than the difference between standard tires and 4 RFTs. It's all about that lowered weight and fuel economy.

Pretty surprised that all we get is a mobility kit tho. I'm kind of leaning towards carrying a spare but I may just get my car flatbedded if I do get a flat.

[AndroidRobot]

Originally Posted by spetsnazos

Debatable, but I do agree RFTs have too many compromises.

That said the reason they even exist is because of companies like BMW pushing for them. A spare weighs more than the difference between standard tires and 4 RFTs. It's all about that lowered weight and fuel economy.

Pretty surprised that all we get is a mobility kit tho. I'm kind of leaning towards carrying a spare but I may just get my car flatbedded if I do get a flat.

Spare tires can be removed for around town driving and added for road trips. RFTs still weight more than normal tires and you can't just quickly remove them for daily driving so. I keep my spare in the garage unless I'm going on a long trip (100+ miles one way) so the weight remains a non-issue

[aerokubectl]

Originally Posted by AndroidRobot

Spare tires can be removed for around town driving and added for road trips. RFTs still weight more than normal tires and you can't just quickly remove them for daily driving so. I keep my spare in the garage unless I'm going on a long trip (100+ miles one way) so the weight remains a non-issue

You are an atypical consumer. My parents would just leave the spare in there for life until they need it.

BMW has to report their weight with a spare if it was provided and must perform Fuel Economy tests accordingly(don't think like an enthusiast for a sec).

Can you take it off? Sure. But 4 RFTs weigh less than 4 STD tires + a spare.

[Poochie]

Originally Posted by AndroidRobot

Spare tires can be removed for around town driving and added for road trips. RFTs still weight more than normal tires and you can't just quickly remove them for daily driving so. I keep my spare in the garage unless I'm going on a long trip (100+ miles one way) so the weight remains a non-issue

I weighted a Michelin Pilot Super Sport against a RunFlat Pirelli P Zero of equivalent specs and the difference was literally 7 ounce. I weighed various tires to confirm this, they we're all within one pound of each other.

Tire technology has caught to the point where the weight difference negligible and performance is on par with non Run-flats.

Also, as ironic as it sounds, there is actually a performance advantage with runflats simply because the sidewall is reinforced, by design, it doesn't flex as much as non runflat, under heavy rebounds, thus giving the driver a more responsive steering feel.

In addition, at high speeds, there is 100% assurance that run-flats would not blowout, possible causing the vehicle to lose control, as oppose to its counterpart. There are videos online of BMW testing their bullet-proof vehicles, fitted with run-flat tires, which after being shot at with a AK-47, it was still able to be driven off, from the location of the attack. Cool..

Obviously, non run-flats would always champion in conform, due to the pliable sidewalls but the current generation offering of runflats are not that far back in terms of livability.

[VIERsr]

Originally Posted by spetsnazos

You are an atypical consumer. My parents would just leave the spare in there for life until they need it.

BMW has to report their weight with a spare if it was provided and must perform Fuel Economy tests accordingly(don't think like an enthusiast for a sec).

Can you take it off? Sure. But 4 RFTs weigh less than 4 STD tires + a spare.

But 4 rft weight a lot more in term of rotating masses and unsprung masses, which have effects on driving more than a spare tire in the trunk

[AndroidRobot]

Originally Posted by Poochie

I weighted a Michelin Pilot Super Sport against a RunFlat Pirelli P Zero of equivalent specs and the difference was literally 7 ounce. I weighed various tires to confirm this, they we're all within one pound of each other.

Tire technology has caught to the point where the weight difference negligible and performance is on par with non Run-flats.

Also, as ironic as it sounds, there is actually a performance advantage with runflats simply because the sidewall is reinforced, by design, it doesn't flex as much as non runflat, under heavy rebounds, thus giving the driver a more responsive steering feel.

In addition, at high speeds, there is 100% assurance that run-flats would not blowout, possible causing the vehicle to lose control, as oppose to its counterpart. There are videos online of BMW testing their bullet-proof vehicles, fitted with run-flat tires, which after being shot at with a AK-47, it was still able to be driven off, from the location of the attack. Cool..

Obviously, non run-flats would always champion in conform, due to the pliable sidewalls but the current generation offering of runflats are not that far back in terms of livability.

I'll have to check bur I'm certain it's more than 7 ounces unless they dramatically improved them. I don't like how they ride regardless, bouncy hard hits aren't exactly confidence inspring plus I promise they can still blow out like a normal tire.

[Poochie]

Originally Posted by AndroidRobot

I'm certain it's more than 7 ounces

I know on this forum some of you guys don't believe in actual proof but here goes nothing:



.

[Poochie]

The Pirelli P Zero runflats are standard equipment on a 1/2 million dollar Bentley, so it must be shit


.

[Thescout13]

Originally Posted by Poochie

The Pirelli P Zero runflats are standard equipment on a 1/2 million dollar Bentley, so it must be shit


.

Yeah, because sponsorships and manufacturer incentives don't mean shit.

I love how people assume expensive luxury brands don't cheapen out here and there if it will increase profits. As if they aren't for-profit businesses. There are plenty of examples of this, e.g., the 914's notoriously cheap fuel lines for one, BMW's plastic water pumps in the e90, Lamborghini countach's A/C components, etc.

[Poochie]

Originally Posted by Thescout13

Yeah, because sponsorships and manufacturer incentives don't mean shit.

Yes because when you're designing a vehicle for the ultra-wealthy, with an almost unlimited budget, saving a buck is the first thing they consider.

[aerokubectl]

Originally Posted by _RS4_

But 4 rft weight a lot more in term of rotating masses and unsprung masses, which have effects on driving more than a spare tire in the trunk

Actually it's not that simple. The runflats themselves have much lower sidewall hysteresis and as such produce fairly low RR.

Lower tire mass ultimately is a big factor in RR though, but if you're comparing a RFT performance tire to a non RFT performance tire, typically the RFT will test better for RR.

Rotating mass matters heavily on increase of vehicle velocity(not constant speed).

[VIERsr]

Originally Posted by Poochie

I know on this forum some of you guys don't believe in actual proof but here goes nothing:



.

But that's a small tire, not a 19" 245/265

[VIERsr]

Originally Posted by spetsnazos

Actually it's not that simple. The runflats themselves have much lower sidewall hysteresis and as such produce fairly low RR.

Lower tire mass ultimately is a big factor in RR though, but if you're comparing a RFT performance tire to a non RFT performance tire, typically the RFT will test better for RR.

Rotating mass matters heavily on increase of vehicle velocity(not constant speed).

RR is not the only factor to consider, in terms of handling (turn, brake) an heavier wheel has a lot of disadvantages.

[Poochie]

Originally Posted by _RS4_

But that's a small tire, not a 19" 245/265

Really, I didn't know that..

Pound for pound, I was contrasting one comparable tire to the other.

Meaning a 245/265 non-RF vs 245/265 RF would extrapolate that they're less than one pound of each other, regardless of the size.

I personally weighed two 19" inch tires (245/30/19), the copy and paste post was a separate B&W reference.

[aerokubectl]

Originally Posted by _RS4_

RR is not the only factor to consider, in terms of handling (turn, brake) an heavier wheel has a lot of disadvantages.

I'm well aware haha. I'm talking about RR because overall weight and RR are huge factors in choosing a RFT tire for a vehicle manufacturer.

Your guys' head would explode how crazy some of the targets set by OEs for RR on high performance cars. You as an end consumer only look at the MPG numbers, but they need to bump the avg across their whole production line and every bit matters.

[aerokubectl]

In case anyone is curious but the construction on a RFT involves a beefier Apex and a second Apex up the sidewall. The shoulder itself is usually of a harder(less hysteretic) compound. The sidewall ply cords are also higher strand/density.

[aerokubectl]

Originally Posted by _RS4_

RR is not the only factor to consider, in terms of handling (turn, brake) an heavier wheel has a lot of disadvantages.

https://www.vox.com/2019/4/6/18295544/epa-california-fuel-economy-mpg

[MyBimmer328]

This is all I see when I look at the grill...

[Artemis]

Deleted a couple of 'deer fight' posts in this thread. Discussions may be tight, but try to avoid getting personal.

[Poochie]

Originally Posted by Artemis

Deleted a couple of 'deer fight' posts in this thread. Discussions may be tight, but try to avoid getting personal.

Sorry but some keyboard warriors here hold internet grudges and animosity for no good reason. It stifles the original subject and causes unnecessary bickering.

Some folks here need to take some advice from Frozen and just "let it go."

[drgmt]

The A45 AMGS It's definitely a competitor.

It's drift mode will definitely make it fun. The interior is superb. Hand built engine.

The only deficiency it has is sound. Looks are of course subjective.

The Audi 5 cylinder is still the benchmark in this segment in terms of sound and tuneability. Stage 1 map and e85 and it's 500 hp straight off. The A45 is probably at its limits and you'll really have to spank the crap out of it to extract its power. The flip side is it feels angry and fast.

The M2 competition is a great car - but this is definitely a worthy competitor.