[Ristau]

I have seen a lot of confusion, and have even myself been confused about the naming scheme of the new BMW cars. Obviously the first number refers to the series, but in the past it is generally well known that the following 2 numbers referred to the displacement.

However, seeing as my 335i does not have a 3.5L engine, this is obviously not the case. However, after looking at a few dyno charts for the different engines, I have come up with an idea.

Last night, I stumbled upon the dyno chart that the guys at Burger Motorsports posted, and using an online calculator to convert wheel horsepower to crank horsepower (a quick google search links to a UK website), I plugged in some of the numbers and got some interesting results.

N55/335i: Online dyno suggests ~ 293 RWHP which translates to 352 crank. Rounded at 350, you get your 35.
B58/340i: Burger - 331 RWHP translates to 397 crank horsepower on a modern automatic (with the calculator I was using). Round that to 400 and you get your 40.
N20/328i: Online dyno suggests ~ 228 RWHP translated to 277 crank. Round that to 280, and you get your 28.
B48/330i: BMWUSA online suggests - 248 Horsepower, which if we assume to be the wheel horsepower (since all these motors seem underrated), comes out to exactly 300 Horsepower. And that is where you get your 30.

Seeing as I have only owned my BMW for about 4 weeks, and came from a Scion and a Toyota before that, I am still learning about the brand. From searching online, however, I have not yet seen any real logic behind the naming convention.

Could it be, that BMW has been hiding their "true" horsepower numbers in their naming schemes for the last few years?

Let me know what you think, or if I am late to the show and the naming scheme is already an established fact. Thanks!

[jmull3r]

that actually makes a lot of sense lol thats pretty cool

[raqautle]

That makes a lot of sense, but if it is actually where it comes from, it'll be so much easier to figure out how much power a car really makes

[MuffinMan910]

Makes a lot of sense, could be true. Thanks for sharing!

[HighlandPete]

So how do we explain the 320d (US 328d), same engine and output? 530d (US 535d), same engine and output?

It is not new to have 'unmatched numbering'. In part it is marketing of outputs and model placement.

[goj]

Originally Posted by HighlandPete

So how do we explain the 320d (US 328d), same engine and output? 530d (US 535d), same engine and output?

It is not new to have 'unmatched numbering'. In part it is marketing of outputs and model placement.

*IF* this is true I can see how they wouldn't do it for diesel in the naming scheme since diesels are named to line up with the gas nomenclature.

Honestly I would not be surprised if someone at BMW was having fun when it came to advertising hp/performance.

This all being said. Quarter mile times for the B58 suggest a number between 350 and 370 tops

[F32Fleet]

BMW naming, throughout their history, has been consistently inconsistent with a sprinkle of what appeared to be be consistency.

Example, even numbers weren't always coupes (ex, 3 series coupes, 507).

Last two numbers didn't always denote displacement (ex 1990s 535) or power at the crank (ex E46 330 225hp vs E90 330 255hp. E90 335i vs E90 335d)

[Jaghave]

At the dealer they explain the 340 is listed as 4.0 since it outputs the same as a naturally aspirated 4.0 engine

[Ristau]

Originally Posted by Jaghave

At the dealer they explain the 340 is listed as 4.0 since it outputs the same as a naturally aspirated 4.0 engine

Although that may be true, that is one of the most ridiculous things I have ever heard LOL

[John in VA]

Originally Posted by Ristau

Although that may be true, that is one of the most ridiculous things I have ever heard LOL

That's how they arrived at the nomenclature for the E23 745i, so not so ridiculous. Some references:

1. BMW designated this particular model as 745i instead of 732i Turbo due to the theoretical assumption that the turbocharged motors have about 1.4 times more power than naturally aspirated motors. Thus, 3.2-litre (3205cc) turbocharged motor has "power equivalent" of 4.5-litre (4487cc) motor without forced induction.

2. 745i, that’s a 4.5L V8, right? Wrong! The 745i was arguably BMW’s most egregious departure from the [Series][Engine Size] nomenclature (at least until the current “Xdrive35i” or whatever they’re doing). You see, BMW decided that the turbocharged 3.2L I-6 had comparable power output to a 4.5L naturally aspirated engine (and that most owners would never look under the hood) and decided to go with the bigger number in place of the more accurate letter “T”.

[bratwurst1]

Originally Posted by Jaghave

At the dealer they explain the 340 is listed as 4.0 since it outputs the same as a naturally aspirated 4.0 engine

Same thing my dealer told me so someone at least gave them that line. My 428 for instance he said is equivalent to 2.8L older engine. I pointed out it makes a lot more but whatever.

[HighlandPete]

Originally Posted by John in VA

That's how they arrived at the nomenclature for the E23 745i, so not so ridiculous. Some references:...

Good post, I was also going to post some reference to the 'turbo' 745i.

Plus we have had other anomalies, such as the E39 540i with its 4.4 litre engine. The following model E60, took on the 545i label, with the same engine size, with the more appropriate numbering.

[Mr D]

So with the b58 mppk - shall I change my trunk so it reads

343i ?

[CalCarNut]

Originally Posted by Ristau

I have seen a lot of confusion, and have even myself been confused about the naming scheme of the new BMW cars. Obviously the first number refers to the series, but in the past it is generally well known that the following 2 numbers referred to the displacement.

However, seeing as my 335i does not have a 3.5L engine, this is obviously not the case. However, after looking at a few dyno charts for the different engines, I have come up with an idea.

Last night, I stumbled upon the dyno chart that the guys at Burger Motorsports posted, and using an online calculator to convert wheel horsepower to crank horsepower (a quick google search links to a UK website), I plugged in some of the numbers and got some interesting results.

N55/335i: Online dyno suggests ~ 293 RWHP which translates to 352 crank. Rounded at 350, you get your 35.
B58/340i: Burger - 331 RWHP translates to 397 crank horsepower on a modern automatic (with the calculator I was using). Round that to 400 and you get your 40.
N20/328i: Online dyno suggests ~ 228 RWHP translated to 277 crank. Round that to 280, and you get your 28.
B48/330i: BMWUSA online suggests - 248 Horsepower, which if we assume to be the wheel horsepower (since all these motors seem underrated), comes out to exactly 300 Horsepower. And that is where you get your 30.

Seeing as I have only owned my BMW for about 4 weeks, and came from a Scion and a Toyota before that, I am still learning about the brand. From searching online, however, I have not yet seen any real logic behind the naming convention.

Could it be, that BMW has been hiding their "true" horsepower numbers in their naming schemes for the last few years?

Let me know what you think, or if I am late to the show and the naming scheme is already an established fact. Thanks!

Pretty cool theory but I don't think the parasitic loss is @18%...

[RPM90]

Originally Posted by Ristau

I have seen a lot of confusion, and have even myself been confused about the naming scheme of the new BMW cars. Obviously the first number refers to the series, but in the past it is generally well known that the following 2 numbers referred to the displacement.

However, seeing as my 335i does not have a 3.5L engine, this is obviously not the case. However, after looking at a few dyno charts for the different engines, I have come up with an idea.

Last night, I stumbled upon the dyno chart that the guys at Burger Motorsports posted, and using an online calculator to convert wheel horsepower to crank horsepower (a quick google search links to a UK website), I plugged in some of the numbers and got some interesting results.

N55/335i: Online dyno suggests ~ 293 RWHP which translates to 352 crank. Rounded at 350, you get your 35.
B58/340i: Burger - 331 RWHP translates to 397 crank horsepower on a modern automatic (with the calculator I was using). Round that to 400 and you get your 40.
N20/328i: Online dyno suggests ~ 228 RWHP translated to 277 crank. Round that to 280, and you get your 28.
B48/330i: BMWUSA online suggests - 248 Horsepower, which if we assume to be the wheel horsepower (since all these motors seem underrated), comes out to exactly 300 Horsepower. And that is where you get your 30.

Seeing as I have only owned my BMW for about 4 weeks, and came from a Scion and a Toyota before that, I am still learning about the brand. From searching online, however, I have not yet seen any real logic behind the naming convention.

Could it be, that BMW has been hiding their "true" horsepower numbers in their naming schemes for the last few years?

Let me know what you think, or if I am late to the show and the naming scheme is already an established fact. Thanks!

Uh, not really.

BMW has used the naming scheme of using series plus engine displacement by which to "name" the various models. But, even that was not consistent as a poster above pointed out.
They stopped doing the series+engine displacement a while ago to much consternation by those who loved the former scheme. BMW has gone to a naming scheme where the "name" starts with the series and then the next 2 numbers represent a value of perceived performance.
What does that mean? It means, if a former 328i had a certain level of 3 series performance with a 2.8 liter engine, then a new 3 series with a higher level of performance with a 2.0 liter turbo engine could easily be called a "330i". A former 330i with a naturally aspirated 3.0 engine could easily be replaced with a new 3 series with a 3.0 liter turbo that kicks the former NA 330i's butt, and it can be called a "335i", and when a higher powered 3.0 turbo engine gets put into a mid life cycle refresh, then the new one can be a "340i".
See?
Clear as mud, no?

And that's all there is to it.

[CalCarNut]

Really, the only model that makes any logical sense is the 320..3 series, 2 liter. The 335 might have had it been the 5th generation of 3 series....with a 3.0liter. Hypothesis abound!

[tturedraider]

Originally Posted by F32Fleet

BMW naming, throughout their history, has been consistently inconsistent with a sprinkle of what appeared to be be consistency.

Example, even numbers weren't always coupes (ex, 3 series coupes, 507).

Last two numbers didn't always denote displacement (ex 1990s 535) or power at the crank (ex E46 330 225hp vs E90 330 255hp. E90 335i vs E90 335d)

Originally Posted by John in VA

That's how they arrived at the nomenclature for the E23 745i, so not so ridiculous. Some references:

1. BMW designated this particular model as 745i instead of 732i Turbo due to the theoretical assumption that the turbocharged motors have about 1.4 times more power than naturally aspirated motors. Thus, 3.2-litre (3205cc) turbocharged motor has "power equivalent" of 4.5-litre (4487cc) motor without forced induction.

2. 745i, that’s a 4.5L V8, right? Wrong! The 745i was arguably BMW’s most egregious departure from the [Series][Engine Size] nomenclature (at least until the current “Xdrive35i” or whatever they’re doing). You see, BMW decided that the turbocharged 3.2L I-6 had comparable power output to a 4.5L naturally aspirated engine (and that most owners would never look under the hood) and decided to go with the bigger number in place of the more accurate letter “T”.

these. BMW has never been as consistent with their numbering as many folks seem to think.

[Ristau]

Originally Posted by CalCarNut

Pretty cool theory but I don't think the parasitic loss is @18%...

Your math is off; it's more like 16%.

Either way, I thought it was a coolish coincidence.

[wrickem]

Now if BMW would just stop naming cars with 4 doors "coupes"

[AGONXF30]

Originally Posted by wrickem

Now if BMW would just stop naming cars with 4 doors "coupes"

Technically they are coupes. The old 3 series 2 door up to about the E 92 was a 2 door sedan. The E30 two door was not a coupe, but a two door sedan.

[wrickem]

Originally Posted by AGONXF30

Technically they are coupes. The old 3 series 2 door up to about the E 92 was a 2 door sedan. The E30 two door was not a coupe, but a two door sedan.

I get the technical definitions based on volume stuff, but still as annoying as Hell. Look up "coupe definition" in any search engine and most of the hits will start with "2 door" and then you'll find the ones with the "technical" reasons why it's a couple. Ask 10 people what "Coupe" means and at least 9 will say 2 doors, the 10th will be a know-it-all. It's especially fun when you are looking for a car with 2 doors on dealer listings and under "coupe" there are cars with 4 doors. I will never recognize a 4 door as a coupe, and I will never recognize you as my son (oh, sorry, that was for someone else, carry on )

http://www.flemingtonbmw.com/searchnew.aspx

[CalCarNut]

Originally Posted by Ristau

Your math is off; it's more like 16%.

Either way, I thought it was a coolish coincidence.

My math is fine..but yes, it is a cool coincidence.