Coupe Economy and MPG

[npd2983]

The official 128i and 135i press release touts the benefit of the on-demand engine coolant pumps:

"Both engines feature on-demand engine coolant pumps that improve fuel economy and reduce parastic losses for increased output."

How much do we honestly expect this to improve fuel economy (and performance)? Personally I expect it to be about 1%-2%, which seems almost negligible. Would this even have a noticeable affect for car owners?

It is apparently a win/win technology because on one hand it increases fuel economy which should appeal to the 128i buyer and on the other hand it increases performance which should help BMW squeeze in another smidgen of performance enhancing technology for the 135i buyer.

Maybe BMW is putting this out there to appease the green crowd? More likely it is a "no brainer." Is this technology in use on other BMW models currently?

Look forward to the responses...

-npd2983

[ducati]

BMW Efficient Dynamics:
http://************/2ozjh6

BMW is doing it because eventually they will have to pursue greener technologies. They are known as the "Ultimate Driving Machine" and as such need to be able to provide the best of both worlds to suit their buyers, even as emissions and fuel economy regulations get tougher.

FWIW, I scanned Bimmerforums one evening for folks who posted real-world mileage numbers. I wrote them down, added them up, and divided by the number of answers in each column.

335 in-town avg: 17.9
335 Mixed: 22.2
335 Highway: 29.3

328 in-town: 21.8
328 Mixed: 24.5
328 Highway: 30.1

I suspect the 128/135 will achieve largely the same figures, maybe ever so slightly better. It is clear that the more you're in the boost, the more fuel the 135 will use. In my experience, turbo engines can get shockingly good fuel economy for their levels of power--but only if you drive very conservatively. Start using that power, and your mileage goes down significantly.

I suspect, with my commute, regular weekend errand running, and drive style, that I would average about 22 in the 135 and 26 in the 128.

[Propagator]

Originally Posted by npd2983

The official 128i and 135i press release touts the benefit of the on-demand engine coolant pumps:

"Both engines feature on-demand engine coolant pumps that improve fuel economy and reduce parastic losses for increased output."

Maybe it's just me, but I don't feel very comfortable trusting BMW cooling on BMW electronics. This is of course just hearsay, as I have not owned a Bimmer.

[bobajoul]

Before all the "experts" weigh in on the mileage figures, I would remind all that this is not the same configuration as the current 3 series. They are touting their "efficient Dynamics" or something to that effect. This is going to involve regenerative brake production, a glass mat battery, whatever that is, and a slew of other things. This will likely create 10-15% improvement by reduction of parasitic drag by the alternator, etc. Technologies that are a big part of hybrids, yet few people understand their real contribution.

[npd2983]

I've just read a bit more about the fuel economy features on the 1 series. This is about the 1 series in Europe, so I'm not sure how much of these technologies will make it to the US 128i and/or the 135i.

BMW's Brake Energy Regeneration uses an Intelligent Alternator Control and an Absorbent Glass Mat battery to capture and release kinetic energy. Traditionally this energy is converted to heat (this is why only a fool would touch brake pads - because they will burn the &^%$^ out of your fingers). Now this energy will be reused to improve mileage. This system intelligently reduces drag on the engine by only engaging when required to charge the battery, whereas a traditional alternator is always harnessed to the engine, dragging it down. Additionally, the energy generated by braking or "engine breaking" charges the battery. In Europe, these features are said to provide a three per cent improvement in fuel economy.

Only the "intelligent alternator" part of this feature is mentioned in the official US press release, so I'm not sure if the entire system will make it to the US (the press release is just an overview, not always so detailed) or just the one component. I hope the whole system will make it to the US.

There is the possibility of an automatic Start-Stop function that switches the engine off when the vehicle is stopped and put in neutral. Pretty much like a hybrid car, to restart the driver reflexively engages the clutch again before pulling away. Just like some hybrid cars, there is a buttom to shut this function off if it is not desired. This is not offered on the 130i in Europe, so I'm not sure if it will be on either US model. Cost would be the only reason not to offer it, especially if there is a manual override button.

Electric Power Steering is supposed ot save 90% energy saving compared to conventional mechanical hydraulic steering. An electric motor would provide power assistance only when needed (such as turning...DUH).

Of course there are other minor features mentioned:

• The air-conditioning power supply being disconnected from the drivetrain when not in use
• Automatically closing flaps behind the kidney grille to improve economy

I am not sure how many of the features will make it to the 128i and/or the 135i. I hope all of them. I would love to see MPG figures for the 1 series that are noticeably better than the 3 series. Getting noticeably higher mileage may open up a bit more market for the 1 series in the US while steering clear of 3 series territory.

Cheers!

[ducati]

The auto start-stop (which is sweet!) is only available on 4 cylinder 1er's, with manual trannies. So unless something changes, this will not be available in the US.

I think BMW "Efficient Dynamics" technology is quite neat. The link I posted above is fun.

[Victor.L3IchibanM3]

Originally Posted by ducati

The auto start-stop (which is sweet!) is only available on 4 cylinder 1er's, with manual trannies. So unless something changes, this will not be available in the US.

I think BMW "Efficient Dynamics" technology is quite neat. The link I posted above is fun.

WTF are you talking about :iono: How come it shows on the 1coupe preview and the last time I had a 3 series, I had a stick and a start botton

[mikeo]

Originally Posted by Victor.l3ichiban

WTF are you talking about :iono: How come it shows on the 1coupe preview and the last time I had a 3 series, I had a stick and a start botton

He's talking about the feature of the engine turning off at a stoplight or such, then restarting when you want to get underway again--all automatically. Sort of like a gas golf cart, but more smoothly implemented.

[aesthetect]

Originally Posted by npd2983

BMW's Brake Energy Regeneration uses an Intelligent Alternator Control and an Absorbent Glass Mat battery to capture and release kinetic energy. Traditionally this energy is converted to heat (this is why only a fool would touch brake pads - because they will burn the &^%$^ out of your fingers). Now this energy will be reused to improve mileage. This system intelligently reduces drag on the engine by only engaging when required to charge the battery, whereas a traditional alternator is always harnessed to the engine, dragging it down. Additionally, the energy generated by braking or "engine breaking" charges the battery. In Europe, these features are said to provide a three per cent improvement in fuel economy.

Only the "intelligent alternator" part of this feature is mentioned in the official US press release, so I'm not sure if the entire system will make it to the US (the press release is just an overview, not always so detailed) or just the one component. I hope the whole system will make it to the US.

there is no regenerative braking in the true sense that there is with hybrid vehicles (which actually have a motor/generator attached to the wheel/axle). from what i've read it is, as said, just an "intelligent alternator" that charges the battery when the motor isn't under load (ie. alternator charges battery when in neutral, when engine braking, etc) and only when the battery needs charging.

Absorbent Glass Mat battery is just a battery utilizing new technology. its the exact same functionality, just does so better (discharges more slowly, lower internal resistance etc).
http://en.wikipedia.org/wiki/Absorbent_glass_mat

i wish they would just throw on the engine start stop.. it cant be that costly to implement and screw consumer acceptance if it can so easily be turned on/off.

[ducati]

It's not a free lunch, though--it requires quite a large starter to implement the auto start feature.

[npd2983]

This is some cool info that came out today. I suspect once BMW starts selling the 1 series, particularly the 128i, these CO2 numbers will continue to drop. If BMW introduces a couple of turbo diesels to the US market they can certainly drive these numbers even lower while continuing to offer fun to drive cars. Also a factor - how many BMW models will include the "efficiency dynamics" in the future?

Trucks and SUVs drive these numbers up for most auto makers. BMW did introduce the X models which increased the numbers, but these were clearly both offset and bettered by BMW's more efficient engines for all models across the board. I am glad BMW has been consistent with measured and conservative power increases among the I-6 engines instead of heavily adopting V-6 and V-8 engines.

Total change in per-vehicle carbon emissions between 1990 and 2005 models:

Toyota: down 3 percent
Nissan: up 9.2 percent
Ford: up 4.7 percent
DaimlerChrysler: up 4.8 percent
General Motors: up 3 percent
Honda: up 4.4 percent
BMW: down 12.3 percent
Volkswagen AG: up 1.3 percent
Kia: up 30 percent
Hyundai: up 17 percent

Regards,
npd2983

[npd2983]

In searching the Internet for possible 1 Series MPG, I found a recent estimate from an article at thecarconnection.com

Fuel economy (city/hwy, est): 128i manual21/30 mpg; 135i manual 20/30 mpg

We are all guessing until the official figures come out; hopefully they will be close to or better than these numbers.

Regards,
npd2983

[RayI]

I am confused and looking for some clarification. The mpg for the 135i is listed as 21.7/40.4 with an unloaded weight of 3267 lbs. I checked the same numbers for a 335 sedan or coupe as: 19/29 at ~ 3500 lbs. So, why should the 135i get so much better mileage on the highway than the 335? It can not be the weight difference.

[RayI]

I think I see the reason for the difference. The 40.4 is quoted as mpg but probably UK gallons. There are 0.833 UK gallons per US gallon. Therefore, the 40.4 mpg number is really 40.4 mpg(UK)* 0.833 = 33.6 mpg(US). This is more reasonable.

[Nixon]

Originally Posted by RayI

I am confused and looking for some clarification. The mpg for the 135i is listed as 21.7/40.4 with an unloaded weight of 3267 lbs. I checked the same numbers for a 335 sedan or coupe as: 19/29 at ~ 3500 lbs. So, why should the 135i get so much better mileage on the highway than the 335? It can not be the weight difference.

This is like comparing apples to oranges. There isn't any other country in the world that uses our EPA fuel consumption tests to determine mpg numbers. In fact, not even the US is going to be using the current EPA tests anymore. A new system is being rolled out in 2008. Any official US mpg numbers for the 135i will most likely be done using the new EPA test which are expected to give lower numbers across the board for all cars.

So don't expect to hear any really good numbers like 21/30. It just won't happen under the new EPA tests due in 2008. The 335i AT dropped from 20/29 to 18/26 under the new test. Follow the "what's new" link here:

http://www.fueleconomy.gov/

The British mpg numbers are done at steady speed on the highway, using Imperial gallons. They don't speed up and slow down like the EPA highway loop test. There is no way to predict EPA numbers based upon British numbers. They just don't measure the same thing.

[Khobin~]

That's because EPA numbers are based on measuring emission levels(at least partially) which makes them very unrealistic when looking at ULEV's.

For instance, my old Lancer was EPA rated around 25 city, 38 hwy...I never got more the 28 mpg on the hwy.

And from info I've seen on the net it was much worse at reflecting the "true" MPG's of Hybrid vehicles.

The new system is supposed to give numbers that are much more accurate to "real world" driving.:thumbup:

To sum up: EPA #'s don't mean shit.

[aesthetect]

i think the "combined cycle" is fairly reflective if my daily driving habits.. i'd like to know specifically how they are changing the cycles. but it is certainly time for them to get an update.

i believe last i heard (several years ago) there was supposed to be some element of randomness. or something to that effect to account for hybrid car manufacturer's inherent ability to tailor their control systems to max EPA test mpg performance.

[Khobin~]

I first read an article on it some time ago now, and can't find that particular one, but this one does a pretty good job of outlining the "old" EPA system.

http://autos.msn.com/advice/article....tentid=4023628

From some artilces I found quikcly it seems that the "new" system will involve trying to simulate more realistic "real-world" conditions.

[aesthetect]

yeah but that was the idea with the old ones too