[AWM235i]

can someone explain all the updates to the auto ZF transmission? I use to have a ZF M235i that was best auto trans I've had but there was room for improvement.

[techwhiz]

All I can say is at 3200lbs unladen, it's porky.
My car is at 3500lbs, but it's a four door.

BMW stop adding pork. Trim that waistline.

Also information about the transmission:
https://en.wikipedia.org/wiki/ZF_8HP_transmission

[XutvJet]

Originally Posted by techwhiz

All I can say is at 3200lbs unladen, it's porky.
My car is at 3500lbs, but it's a four door.

BMW stop adding pork. Trim that waistline.

LOL. A C7 Corvette weighs between 3,347 to 3,523lbs. A 2016 Camaro SS weighs ~3,350lbs. A Mustang GT350 ~3,500lbs. A 2015 WRX STI weighs in at 3,450lbs. A 2016 Focus RS weighs in at 3,525lbs.

I think all things considered, the M235/M240 are doing ok. My 2016 M235 6MT with no moonroof and 3/4 tank of fuel weighed in at 3,350lbs on a CAT scale.

[bradleyland]

Originally Posted by XutvJet

LOL. A C7 Corvette weighs between 3,347 to 3,523lbs. A 2016 Camaro SS weighs ~3,350lbs. A Mustang GT350 ~3,500lbs. A 2015 WRX STI weighs in at 3,450lbs. A 2016 Focus RS weighs in at 3,525lbs.

I think all things considered, the M235/M240 are doing ok. My 2016 M235 6MT with no moonroof and 3/4 tank of fuel weighed in at 3,350lbs on a CAT scale.

Some of your weights are off. Some by quite a bit (Camaro SS). Many of the cars you listed are also much larger than the M235i, or they're AWD. To compare to AWD, add 190 lb.

A good way to compare the relative weight of a car is to compare footprint density. That is: weight/(length x width). In this comparison, the M240i shows its relative heft.



You can see the data I used to calculate these measurements here:

https://docs.google.com/spreadsheets...it?usp=sharing

Note that we could use volume, rather than footprint, but no car is a perfect cube. This is especially true for the vertical dimension. Nearly a third of a car's height is in space between the top of the door and the roofline. Using volume skews the results in a way that doesn't represent the "size" of a vehicle as it is normally perceived.

[XutvJet]

My weights are taken directly from the manufacturer's except for mine which was weighed locally. Yes, the STI and RS are AWD, but they're souped up econoboxes with little refinement to weigh them down. The AWD system in the STI isn't heavy at all. The extra diff (built into the tranny), two extra axles, and the DCCD (transfer unit) weigh in around 140lbs.

Who cares about foot print density either? Never heard of anyone referring to that. The 2 series is arguably a perfect size for a sports coupe and MUCH smaller than a Mustang or Camaro. Small, easy to see out of cars instill driver confidence. A Camaro? LOL, report back to me after you drive one.

All things considered, the 2 series weight is right there in it's class and certainly isn't one of the heavier ones. Plus it has a useable back seat. Could it be lighter? Sure, but you'll pay more for the use of lightweight materials. This isn't 1988. Cars are far safer and laden with safety and creature tech now. Plus this is a BMW thus there is a level of refinement expected.

[bradleyland]

Originally Posted by XutvJet

My weights are taken directly from the manufacturer's except for mine which was weighed locally. Yes, the STI and RS are AWD, but they're souped up econoboxes with little refinement to weigh them down. The AWD system in the STI isn't heavy at all. The extra diff (built into the tranny), two extra axles, and the DCCD (transfer unit) weigh in around 140lbs.

Who cares about foot print density either? Never heard of anyone referring to that. The 2 series is arguably a perfect size for a sports coupe and MUCH smaller than a Mustang or Camaro. Small, easy to see out of cars instill driver confidence. A Camaro? LOL, report back to me after you drive one.

All things considered, the 2 series weight is right there in it's class and certainly isn't one of the heavier ones. Plus it has a useable back seat. Could it be lighter? Sure, but you'll pay more for the use of lightweight materials. This isn't 1988. Cars are far safer and laden with safety and creature tech now. Plus this is a BMW thus there is a level of refinement expected.

That's a lot of words that don't refute what I said.

If you care about facts, then the 2-series is heavy for its size. It's still a great car, but it's heavy for its size.

[XutvJet]

Originally Posted by bradleyland

That's a lot of words that don't refute what I said.

If you care about facts, then the 2-series is heavy for its size. It's still a great car, but it's heavy for its size.

OK, so how about this consideration. An E46 M3 6MT, which many say is the greatest BMW coupe ever, weighed in at 3,420lbs per BMW all the way back in 2001. The M235 6MT is basically the same size in every dimension plus it's sporting the extra weight of a turbo and ancillary parts, a far stiffer body, and a bit more tech, yet weighs 3,490lbs per BMW. So the 2016 M235 weigh around 2% more than the 2001 M3. Not exactly a huge difference in weight over 15 years considering all the improvements, a turbo, and FAR MORE safety and survivability.

Would you say the E46 M3 was a heavy car?

[bradleyland]

Originally Posted by XutvJet

OK, so how about this consideration. An E46 M3 6MT, which many say is the greatest BMW coupe ever, weighed in at 3,420lbs per BMW all the way back in 2001. The M235 6MT is basically the same size in every dimension plus it's sporting the extra weight of a turbo and ancillary parts, a far stiffer body, and a bit more tech, yet weighs 3,490lbs per BMW. So the 2016 M235 weigh around 2% more than the 2001 M3. Not exactly a huge difference in weight over 15 years considering all the improvements, a turbo, and FAR MORE safety and survivability.

Would you say the E46 M3 was a heavy car?

OK, take a step back before you wade in to this discussion with blinders on. The E46 M3 might be the greatest BMW coupe ever, but that has nothing to do with what I'm saying. I've made a statement of fact, and backed it up with data.

Fact: The M235i is heavy for its size.

All the information I've provided is in the context of other cars that you provided. I think you thought you were making a point with that list, but it actually proves the opposite of what you said. You could look at that and think "Hey, the 2-series is heavier than I thought." Or you could think, "Wow, those other cars aren't as heavy as I thought." Or you can continue to look past the facts and bask in ignorance.

I'm not sure what point you're trying to make.

The M235i/M240i are great cars? Agreed.

The E46 M3 was a great car? Agreed.

The M235i/M240i are relatively heavy cars though. They're not exactly pigs, but they're marginally heavy when compared to the examples you provided.

[boostm3]

Originally Posted by XutvJet

LOL. A C7 Corvette weighs between 3,347 to 3,523lbs. A 2016 Camaro SS weighs ~3,350lbs. A Mustang GT350 ~3,500lbs. A 2015 WRX STI weighs in at 3,450lbs. A 2016 Focus RS weighs in at 3,525lbs.

I think all things considered, the M235/M240 are doing ok. My 2016 M235 6MT with no moonroof and 3/4 tank of fuel weighed in at 3,350lbs on a CAT scale.

Wrong! 2016 Camaro SS Manual has a curb weight of 3685 lbs.

[drakensoul]

Originally Posted by bradleyland

You can see the data I used to calculate these measurements here:

I'm not sure I buy a weight per size measurement (density) as an indication of porkosity. The above chart is more a function of the molar weight of the chassis/car substrate than it is a measure of performance-per-weight, which is what the weight of the car is really affecting. Because the frame could be 300000000000000 square feet of some futuristic feather-weight metal and severely skew it; likewise it could be 30 square feet of cast iron and sway it.

Density = M/V, so you can make things more or less dense simply by changing the volume. So I could take your chart above and say, "Okay, let's increase the wheelbase by 50%," effectively decreasing the density by 50%. Does that mean the car is any less "porky?" not by any relevant standard, it's meaningless data-shifting. It performs the same in a straight line. Likewise I can say "Let's take the 3-series and decrease the wheelbase by 16%," which makes it more dense. But again, has any real performance metric changed? No.

The 2-series is a smaller car with the same things (weight) as a larger variant, so of course it is more dense. But density is fairly esoteric with regard to a vehicle because, as above, it has no real performance data implication. It doesn't necessarily mean anything has been "added" to the vehicle.

The variable that DOES relate to adding to the vehicle is the vehicle weight (mass). If the car is heavier, it performs more poorly regardless of its density. In that way, the equation becomes a function of weight instead of density, and there's already a tried-and-true method of interrelating performance based on weight:

Pounds/hp. How much weight does each hp have to pull?

A semi has a gigantic volume and thus a very low density (lb/sq. ft); would you contend that a semi is more weight-optimal and performs better than a smaller, less massive sports car?

Probably not.

[bradleyland]

Originally Posted by drakensoul

I'm not sure I buy a weight per size measurement (density) as an indication of porkosity. The above chart is more a function of the molar weight of the chassis/car substrate than it is a measure of performance-per-weight, which is what the weight of the car is really affecting. Because the frame could be 300000000000000 square feet of some futuristic feather-weight metal and severely skew it; likewise it could be 30 square feet of cast iron and sway it.

Density = M/V, so you can make things more or less dense simply by changing the volume. So I could take your chart above and say, "Okay, let's increase the wheelbase by 50%," effectively decreasing the density by 50%. Does that mean the car is any less "porky?" not by any relevant standard, it's meaningless data-shifting. It performs the same in a straight line. Likewise I can say "Let's take the 3-series and decrease the wheelbase by 16%," which makes it more dense. But again, has any real performance metric changed? No.

The 2-series is a smaller car with the same things (weight) as a larger variant, so of course it is more dense. But density is fairly esoteric with regard to a vehicle because, as above, it has no real performance data implication. It doesn't necessarily mean anything has been "added" to the vehicle.

The variable that DOES relate to adding to the vehicle is the vehicle weight (mass). If the car is heavier, it performs more poorly regardless of its density. In that way, the equation becomes a function of weight instead of density, and there's already a tried-and-true method of interrelating performance based on weight:

Pounds/hp. How much weight does each hp have to pull?

A semi has a gigantic volume and thus a very low density (lb/sq. ft); would you contend that a semi is more weight-optimal and performs better than a smaller, less massive sports car?

Probably not.

That's kind of the question being asked though: is the M240i heavy for its size? You cold boil it down to density, but we don't really perceive cars by volume, specifically. I think most would agree ? and it's certainly a matter of opinion ? that a car's perceptive size is most heavily influence by length. That's why I used footprint (L x W) and not volume.

[drakensoul]

Originally Posted by bradleyland

That's kind of the question being asked though: is the M240i heavy for its size? You cold boil it down to density, but we don't really perceive cars by volume, specifically. I think most would agree ? and it's certainly a matter of opinion ? that a car's perceptive size is most heavily influence by length. That's why I used footprint (L x W) and not volume.

Your post is boiling it down to a 2D density corollary.

And again the only point is you can stretch or shrink a car to make the blue bar bigger or shorter without actually changing anything relevant.

Where would an empty semi (small bar) or a Mazda Miata (larger bar) fit on your graph? Would you say the Miata is relatively heavier than a semi? If so, what's the point?

The volume, or in this case length of a car doesn't really matter. Making a car longer and thus making its bar smaller and decreasing its footprint density (smaller bar) doesn't make it faster and actually makes it handle worse.

Smaller, more dense cars with an implied better center of mass and less total mass (weight) perform better. Hence using pounds/hp as a meaningful performance metric, whereas no one uses pounds/sq. ft.

[bradleyland]

Originally Posted by drakensoul

Your post is boiling it down to a 2D density corollary.

And again the only point is you can stretch or shrink a car to make the blue bar bigger or shorter without actually changing anything relevant.

Where would an empty semi (small bar) or a Mazda Miata (larger bar) fit on your graph? Would you say the Miata is relatively heavier than a semi? If so, what's the point?

The volume, or in this case length of a car doesn't really matter. Making a car longer and thus making its bar smaller and decreasing its footprint density (smaller bar) doesn't make it faster and actually makes it handle worse.

Smaller, more dense cars with an implied better center of mass and less total mass (weight) perform better. Hence using pounds/hp as a meaningful performance metric, whereas no one uses pounds/sq. ft.

I get what you're saying, but I think it intentionally misses the point. You're welcome to compare an M240i to an empty semi, but I can't recall the last time I cross-shopped the two. You've chosen an intentionally contrived comparison to illustrate a point, but what is the point?

Yes, if BMW were to increase the size of the M240i by a few inches, it would compare better in my examples, but then it would be a 4-series, not a 2-series. Your criticism also ignores the fact that you can't simply expand the size of the car without also increasing the weight.

My point stands that the 2-series is heavy when compared to cars of similar dimension. That, necessarily, correlates to some methodology that calculates density, but density isn't the point.

Everyone should stop bending over backwards to defend the 2-series. Yes, safety is important. Yes, the M240i is a great little car. But it would be improved by a diet.

[ORIGIN M.]

Originally Posted by Alpine F31

Why should we be upset? There are always better, faster, newer cars available no matter what you currently drive. The new (insert sexy car here) is great, but it doesn't make me like my M235i any less. It's still great and it's still way more capable as a car than I am as a driver.

He is saying that because it is sadly true except for a few like you.

[ORIGIN M.]

Originally Posted by ACZakka325i

We are all in for the M2 because of the bespoke M-bits such as:

- M mirrors
- M seats
- M engine
- M hood bulge

It seems as though the M2 really has no place in the lineup any longer and speaks to more reason why the M2 will be more special and limited. From MSRP alone, it appears as though it can't be a money-maker for BMW.

M2 is mostly a marketing tool for BMW over a money maker.

[drakensoul]

Originally Posted by bradleyland

I get what you're saying, but I think it intentionally misses the point. You're welcome to compare an M240i to an empty semi, but I can't recall the last time I cross-shopped the two. You've chosen an intentionally contrived comparison to illustrate a point, but what is the point?

Aww, I thought it was pretty simple At this point it's becoming esoteric and

I thought the point was that density is a poor metric of vehicle performance. That is what you're comparing, no? Otherwise you would have just listed older BMWs compared to newer ones to show that BMWs have become relatively more dense. If you're comparing it to other cars you are implying that it somehow relates to performance, otherwise you're saying something is more dense just to say it's denser with no real purpose. What's the point? I was assuming you weren't making an argument just to beg the question.

I was highlighting that footprint density is a (very) poor comparator of performance by virtue of being almost entirely based on the exponential variable in the denominator (vehicle length and width).

I.e.: you can equilibrate the footprint density of the 235 with the SS by shaving 160 pounds off of the 235, but it's still massively outmatched with its current engine (still 670 pounds overweight to equal performance of the SS based on ~8.2lb/hp for the SS). In other words, the 235 would need to weigh <2700 pounds with its current engine to match the SS's performance, even though it's only 160ish lbs off in density. Quite a gap there, no? Because density doesn't relate well to performance.

Heft/weight per HP is a meaningful comparison variable for performance because it actually is a metric of performance (ability to overcome inertia), and density again plays almost zero role because density is based exponentially on footprint or volume.

But if you were saying that it's denser just to say it's denser... using a formula that has near-zero bearing on performance, then... okay?

Edit: And I don't own or want to own a Camaro! I'm still deciding between used 235 or leasing a new 240.

[XutvJet]

Originally Posted by bradleyland

OK, take a step back before you wade in to this discussion with blinders on. The E46 M3 might be the greatest BMW coupe ever, but that has nothing to do with what I'm saying. I've made a statement of fact, and backed it up with data.

Fact: The M235i is heavy for its size.

All the information I've provided is in the context of other cars that you provided. I think you thought you were making a point with that list, but it actually proves the opposite of what you said. You could look at that and think "Hey, the 2-series is heavier than I thought." Or you could think, "Wow, those other cars aren't as heavy as I thought." Or you can continue to look past the facts and bask in ignorance.

I'm not sure what point you're trying to make.

The M235i/M240i are great cars? Agreed.

The E46 M3 was a great car? Agreed.

The M235i/M240i are relatively heavy cars though. They're not exactly pigs, but they're marginally heavy when compared to the examples you provided.

Agree to disagree then. I'm far from a BMW or M235/240 nutswinger, but I'm also a realist because I know that in order for BMW to shed weight from the M235/240 will add a lot of expense to the car and reduce refinement. It is a sport luxury car after all thus there is an expectation for it to be vault-like and refined. With that comes with some extra weight. Also, the car was designed to be a convertible from the start which can add some weight to the lower portions of the unibody.

The M235/240 not a sports car like a Corvette or the like. Those cars specifically designed to be light 2 seaters with the use of expensive light weigh components, but even then, a Vette doesn't weigh a whole lot less than the M235/240. For it's "class", the M235/M240 comparatively light. A 3,400-3,500lb sports coupe is far from heavy these days and the M235/M240 simply does a better job of managing it's empty voids in the chassis and excessive overhangs. There's simply very little wasted space. It makes absolutely no sense to me how a current gen Mustang which is heavier, much larger on the outside, and yet smaller on the inside isn't considered too heavy by your calculations.

You do realize that most 2 seat supercars are much heavier than the M235/M240, right?

[bradleyland]

Originally Posted by drakensoul

Aww, I thought it was pretty simple At this point it's becoming esoteric and

I thought the point was that density is a poor metric of vehicle performance. That is what you're comparing, no? Otherwise you would have just listed older BMWs compared to newer ones to show that BMWs have become relatively more dense. If you're comparing it to other cars you are implying that it somehow relates to performance, otherwise you're saying something is more dense just to say it's denser with no real purpose. What's the point? I was assuming you weren't making an argument just to beg the question.

I was highlighting that footprint density is a (very) poor comparator of performance by virtue of being almost entirely based on the exponential variable in the denominator (vehicle length and width).

I.e.: you can equilibrate the footprint density of the 235 with the SS by shaving 160 pounds off of the 235, but it's still massively outmatched with its current engine (still 670 pounds overweight to equal performance of the SS based on ~8.2lb/hp for the SS). In other words, the 235 would need to weigh <2700 pounds with its current engine to match the SS's performance, even though it's only 160ish lbs off in density. Quite a gap there, no? Because density doesn't relate well to performance.

Heft/weight per HP is a meaningful comparison variable for performance because it actually is a metric of performance (ability to overcome inertia), and density again plays almost zero role because density is based exponentially on footprint or volume.

But if you were saying that it's denser just to say it's denser... using a formula that has near-zero bearing on performance, then... okay?

Edit: And I don't own or want to own a Camaro! I'm still deciding between used 235 or leasing a new 240.

It's only becoming esoteric because everyone keeps walking right past the point in to some digression about density. Alas, that's the discussion you'd like to have so let's jump right in that pool: Density is bad because it makes cars heavier. Heavy cars are bad when it comes to handling and performance, but more so handling. In order to preserve performance (0-60, 1/4 mile, skid pad, slalom, lap times, etc) you can mitigate weight gain by adding more power, larger tires, brakes, etc. However, it is much more difficult to preserve handling (the way a car feels) as you add weight.

My E92 M3 is the biggest, heaviest car I've ever owned. I love the engine, and I think the car drives well for its size, but it's still too big and too heavy for my taste. When not driven beyond the limits of its suspension, my MkV handled better than my M3. Once you pushed the GTI past 7/10ths, it's poor damping ruined the fun. That car weighed around 2,900 lbs.

If all you care about is chasing numbers, then you're right, density means nothing. Simply dig up all the performance figures you can find, and buy the car that hits the performance targets you're looking for. If you care about handling, then the constant march toward heavier and heavier cars must matter to you. Ultimately, it's the curb weight number that really matters: lower is better. Compared to many of the cars on that list, the M235i/M240i is the lighter car. That's a good thing, but the M235i/M240i are not as light as they could be, and that's a bad thing.

[bradleyland]

Originally Posted by XutvJet

Agree to disagree then. I'm far from a BMW or M235/240 nutswinger, but I'm also a realist because I know that in order for BMW to shed weight from the M235/240 will add a lot of expense to the car and reduce refinement. It is a sport luxury car after all thus there is an expectation for it to be vault-like and refined. With that comes with some extra weight. Also, the car was designed to be a convertible from the start which can add some weight to the lower portions of the unibody.

The M235/240 not a sports car like a Corvette or the like. Those cars specifically designed to be light 2 seaters with the use of expensive light weigh components, but even then, a Vette doesn't weigh a whole lot less than the M235/240. For it's "class", the M235/M240 comparatively light. A 3,400-3,500lb sports coupe is far from heavy these days and the M235/M240 simply does a better job of managing it's empty voids in the chassis and excessive overhangs. There's simply very little wasted space. It makes absolutely no sense to me how a current gen Mustang which is heavier, much larger on the outside, and yet smaller on the inside isn't considered too heavy by your calculations.

You do realize that most 2 seat supercars are much heavier than the M235/M240, right?

Let's be honest, you don't know how much it would cost BMW to make the F22 lighter. Neither do I, so while we can speculate that it would make it more expensive, we don't know by how much. I do know that the F22 chassis shares a lot with the F32 chassis, which is an even bigger, heavier car. So I'd say it's a fair bet that there's some weight savings within reach. BMW just hasn't made it a priority.

If it were so crazy cost prohibitive, why does the i3 weigh 2,900 lbs with a petrol engine and a battery? Without the petrol engine it drops to 2,635 lbs! The i3 with REX starts at $47k. Where's all this crazy expense associated with making a car light?

[bradleyland]

You guys gotta take a step back and look at the discussion being had here. Why is everyone so certain that BMW can't make F22 based cars lighter without the price going up by some ridiculous sum of money? When did everyone decide they'd lay down and stop asking for more from automotive manufacturers. It's no wonder BMW doesn't make a small, lightweight sports coupé. There's an army of unpaid people willing to jump to their defense any time the topic comes up.

It's really confusing to me. There's clear evidence that it's possible to make cars much, much lighter, and at a similar price point, yet droves of people look at what's offered to them and swallow it whole.

[ORIGIN M.]

Originally Posted by bradleyland

You guys gotta take a step back and look at the discussion being had here. Why is everyone so certain that BMW can't make F22 based cars lighter without the price going up by some ridiculous sum of money? When did everyone decide they'd lay down and stop asking for more from automotive manufacturers. It's no wonder BMW doesn't make a small, lightweight sports coupé. There's an army of unpaid people willing to jump to their defense any time the topic comes up.

It's really confusing to me. There's clear evidence that it's possible to make cars much, much lighter, and at a similar price point, yet droves of people look at what's offered to them and swallow it whole.

You need to calm down.

[drakensoul]

Originally Posted by bradleyland

You guys gotta take a step back and look at the discussion being had here. Why is everyone so certain that BMW can't make F22 based cars lighter without the price going up by some ridiculous sum of money? When did everyone decide they'd lay down and stop asking for more from automotive manufacturers. It's no wonder BMW doesn't make a small, lightweight sports coupé. There's an army of unpaid people willing to jump to their defense any time the topic comes up.

It's really confusing to me. There's clear evidence that it's possible to make cars much, much lighter, and at a similar price point, yet droves of people look at what's offered to them and swallow it whole.

Talk about a digression about destiny.

Wooooooosh.

Again, making things weigh less doesn't necessarily have to do with density. It can, but not in your examples.

Again, decreasing heft (weight) increases performance and is a good thing. I was simply stating that attributing that to a decrease in footprint density is fallacious. Since density is a squared inverse function of footprint or volume, and linear in relation to mass.

And also, dense (smaller) cars have better centers of mass as opposed to a theoretically less dense (larger volume) version of themselves. I.e.: a less voluminous, more dense version of your E92 would likely handle better while at the same time performing exactly the same in a straight line.

Again, weight loss is not the same as a decrease in footprint density.

Again, equilibrating the footprint density of the 235 and a Camaro SS doesn't equilibrate their performance (by any stretch).

And also:

But okay.