Soldato
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has any green feature made a fast car faster or lighter ?
2011 M3
- Thread starter Housey
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Soldato
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there was until it got canned.
There is this though
http://www.caranddriver.com/news/car/09q4/2010_bmw_m3_gts-car_news
The system will not turn the engine off if the battery charge is low, or the desired climate temperature hasn't been met, there's condensation on the windscreen etc.
Additionally, brake energy regeneration utilises the kinetic energy of the car to charge and power the electrical system.
Ah ok, Im not sure how much current regenerative braking can supply but an average alternator can supply about 60A so current supply shouldnt be too much of a problem although any extra would be very handy.
Its just I was thinking on a technical level (sad I know but its because Im an engineer) the car must need a pretty hefty battery to take the beating that continuous stop starts whilst keeping everything electrical running constantly would give it.
BMW say they use absorptive glass mat batteries, if that means anything to you
From what I can read they are battery better suited to the sort of load/charge cycle that a start-stop system may place on it, and also the starter motor is designed specifically for start stop systems.
http://en.wikipedia.org/wiki/Absorptive_glass_mat
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Soldato
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Yeah you can deep cycle the glass mats. Basically it supports the plates so you keep a more controlled gap between the plates for the electrolyte as they tend to swell and warp with the heat from high rates of discharge in a short time frame
The regen braking on these systems is simply when the car takes the most charge, it wont make a significant difference to speed retardation. Mines not particularly immense at 50A on a 150V system with a car weighing 840kg.
TBH the hybrids will do the shut down shake better as they can literally stall the engines rather than rely on friction and they are like supercharged starter motors. We struggled at JLR with the 2.2 XF.... oops did I say that To get the 24V micro hybrid system stopping and starting less noticably. Petrol will always be less obvious.
The regen braking on these systems is simply when the car takes the most charge, it wont make a significant difference to speed retardation. Mines not particularly immense at 50A on a 150V system with a car weighing 840kg.
TBH the hybrids will do the shut down shake better as they can literally stall the engines rather than rely on friction and they are like supercharged starter motors. We struggled at JLR with the 2.2 XF.... oops did I say that
To get the 24V micro hybrid system stopping and starting less noticably. Petrol will always be less obvious.
Soldato
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Yeah loads...
Aerodynamics, lower rolling resistance tyres, more efficient oils, alternators that can disengage etc
EDIT> Also why flame BMW? Love or hate the EU war on CO2 (I personally think it's a bit silly) I think what BMW are doing is amazing. They are making sure we can still have quick cars that fit into decent tax brackets. I bet the next gen M3 will be just as quick and probably fall below 225g per km, they are already close! Looking to the diesels - the fact that the new 320ED will sit on the motorway at 75mph getting about 75mpg is an absolutely incredible technical achievement and if I could afford one I'd probably get one! Obviously if I could afford an M3 I'd get that instead - but I think that's going beyond the realms of dreaming to fantasising wildly!
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BMW say they use absorptive glass mat batteries, if that means anything to you
From what I can read they are battery better suited to the sort of load/charge cycle that a start-stop system may place on it, and also the starter motor is designed specifically for start stop systems.
http://en.wikipedia.org/wiki/Absorptive_glass_mat
Excellent, thanks for all the info.
Soldato
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I saw that mentioned in an article, is that appearing in the real world?
Really impressive really for a decent sized proper saloon if thats the case. Mine does about that, although on petrol, but its tiny little 2 seater.
I think short of some revolutionary invention or change of direction, there isn't going to be any huge steps with regards to economy, but rather a continuation of the "baby steps" we have been making already. If you stand back and think... we now have a 4.0 V8 BMW M3 with 420 HP, capable of 190 MPH, returning 25 MPG. That's quite impressive.
![[TW]Fox](/data/man-of-honor/2009.png){kind=avatar}
Same as before though - most of the mid life refresh stuff doesnt apply to the M model. Look at the E46 M3. The facelift gave it.. new backlights, you didnt even get the facelift Coupe front.
Soldato
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[TW]Fox;15956857 said:In my experience of 4 different 2009 ED models, no
The 320 specific model that gets this acclaim in the press? Or other ED variants?
EDIT:
Seems with the aero wheels its 0.26 Cd. Nice
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BMW have put it on to drop the emissions during the NEDC drive cycle which has several idling periods.
By doing this it drops the CO2 and fuel consumption of the model for homologation. If it wasn't for this I doubt they would bother putting it on, fact is on most cars these Efficient dynamics will drop the vehicle tax band as well as reduce the fleet average (very important in 2012)