How sophisticated is SMG?
Discussion
Now I'm well aware that this will polarise views i.e. manual vs SMG as I'm too aware having also got a DSG R32. I was interested to see how similar to DSG the SMG box is or isn't? I have to say that I love DSG and am currently going through a phase of man maths and classifieds browsing. I'm sorely tempted by an M3 or M5 and will obviously go and look at both boxes to see what suits, but would like to hear views from owners on here. Does SMG have acceleration and/or mpg benefits over manual? There seem to be lots about - especially SMG - and I'm aware that it could go wrong, presumably expensively, but I don't think I've ever owned a car that hasn't had some sort of internet based scaremongering regarding a specific part.
In the E46 the SMG lot tend to get slightly lower mpg compared to the manual guys, might be due to using more of the upper rev range more often or more in town/track use. Same gearing and gearbox underneath so driven the same way there should be no difference.
Quicker shift times compared to what you could do with a manual and no missed gears or badly timed shifts, less pure for those who prefer a clutch though.
Quicker shift times compared to what you could do with a manual and no missed gears or badly timed shifts, less pure for those who prefer a clutch though.
You have to remember that the SMG is still a manual box, just that it has no clutch pedal. The system itself is not that mind blowing as far as wizzardry goes but its does a much better job of taming the power from the engine than we could ever do. Early SMG in the E46 was a new concept for M cars and as such it had many teething problems. By the time the late E60 M5's (post 2007) came into being they were running the latest and most reliable systems going.
You have to learn its ways, but it's fun doing it. Suck it and see!
You have to learn its ways, but it's fun doing it. Suck it and see!
SMG I (E36 M3 Evo) was awful to use compared with the manual, felt very slow-witted and unrefined.
SMG II (E46 M3) and SSG (E46 325/330i and E60/1 545i) was vastly improved and for me has as much going for it as the manual and I'd be happy with either and would just buy the car I wanted by condition and be happy with whichever 'box it came with. If anything I'd probably lean toward the two pedal option these days. Although in V8 5 Series and non-M 3 Series form, I'd go with either a manual or torque converter auto instead.
SMG III (E6x M5/6) I have not driven myself, but have been a passenger a few times in and it seems to be much the same and a bit sharper again, although that could just be the extra power making it feel that way. There's no alternative for us in the UK on that one so it's a bit of a moot point.
M DCT (E9x M3 & F10M) is the closest technologically speaking to your DSG as they're both double-clutch pre-selector gearboxes and as such quite different to the foregoing. I've only had a brief play with an M3 DCT and manual and as much as a part of me would like to have the last manual NA M car, it would really be very hard indeed not to choose the DCT box instead, it was great fun, I admit partly because it made an average driver like me feel like I was getting the very best out of the engine and not potentially fluffing shifts.
SMG I and II aren't drastically more technically sophisticated than the regular manual gearbox, all that's happened is a clutch pedal and your foot and brain have been swapped for a hydraulic clutch and actuators and an ECU.
SMG III is more technical as it's not based on any other manual gearbox and due to the shaft layout of the seven gears plus reverse, would be impossible to use as a conventional H pattern 'box as the gears are not in order inside the casing. The E6x manuals that North America got used the E39 M5's gearbox with adjusted rations (which itself was the E34 M5/M3 Evo six speeder IIRC).
DCT is another kettle of fish entirely and similarly unrelated to the M3's alternative manual gearbox.
SMG II (E46 M3) and SSG (E46 325/330i and E60/1 545i) was vastly improved and for me has as much going for it as the manual and I'd be happy with either and would just buy the car I wanted by condition and be happy with whichever 'box it came with. If anything I'd probably lean toward the two pedal option these days. Although in V8 5 Series and non-M 3 Series form, I'd go with either a manual or torque converter auto instead.
SMG III (E6x M5/6) I have not driven myself, but have been a passenger a few times in and it seems to be much the same and a bit sharper again, although that could just be the extra power making it feel that way. There's no alternative for us in the UK on that one so it's a bit of a moot point.
M DCT (E9x M3 & F10M) is the closest technologically speaking to your DSG as they're both double-clutch pre-selector gearboxes and as such quite different to the foregoing. I've only had a brief play with an M3 DCT and manual and as much as a part of me would like to have the last manual NA M car, it would really be very hard indeed not to choose the DCT box instead, it was great fun, I admit partly because it made an average driver like me feel like I was getting the very best out of the engine and not potentially fluffing shifts.
SMG I and II aren't drastically more technically sophisticated than the regular manual gearbox, all that's happened is a clutch pedal and your foot and brain have been swapped for a hydraulic clutch and actuators and an ECU.
SMG III is more technical as it's not based on any other manual gearbox and due to the shaft layout of the seven gears plus reverse, would be impossible to use as a conventional H pattern 'box as the gears are not in order inside the casing. The E6x manuals that North America got used the E39 M5's gearbox with adjusted rations (which itself was the E34 M5/M3 Evo six speeder IIRC).
DCT is another kettle of fish entirely and similarly unrelated to the M3's alternative manual gearbox.
Zwolf said:
SMG III is more technical as it's not based on any other manual gearbox and due to the shaft layout of the seven gears plus reverse, would be impossible to use as a conventional H pattern 'box as the gears are not in order inside the casing.
Does SMG even in manual mode shuffle down the gears as you slow down, or would it stay in the selected gear, say, 5th, until you select neutral or 1st gear yourself ?m3mjw said:
BOR said:
Does SMG even in manual mode shuffle down the gears as you slow down, or would it stay in the selected gear, say, 5th, until you select neutral or 1st gear yourself ?
Changes down for you mateI have had an M6 for years, never drove the new BMW DSG yet, but lots of experience with the Porsche DSG cars.
In auto mode the SG is quite poor. If you floor the car or accelerate aggressively its a jerky old thing. In manual mode, with just a little experience it can be shifted seamlessly and it rev matches on downshift. The Porsche PDK , a true DSG is infinitely better in auto mode, and a little quicker in shifting. I would imagine the BMW DSG is similar.
In auto mode the SG is quite poor. If you floor the car or accelerate aggressively its a jerky old thing. In manual mode, with just a little experience it can be shifted seamlessly and it rev matches on downshift. The Porsche PDK , a true DSG is infinitely better in auto mode, and a little quicker in shifting. I would imagine the BMW DSG is similar.
RDMcG said:
I have had an M6 for years, never drove the new BMW DSG yet, but lots of experience with the Porsche DSG cars.
In auto mode the SG is quite poor. If you floor the car or accelerate aggressively its a jerky old thing. In manual mode, with just a little experience it can be shifted seamlessly and it rev matches on downshift. The Porsche PDK , a true DSG is infinitely better in auto mode, and a little quicker in shifting. I would imagine the BMW DSG is similar.
Not long after i got mine (a week)i had all of the software updated. I alsways drive in manual and have it set to s5 all of the time. I must say i find it changes gear really well and is a lot less lumpy than i thought it was going to be after reading many comments before i got it. Not sure if this is due to it having new software. It is a 2006 car so pre facelift tooIn auto mode the SG is quite poor. If you floor the car or accelerate aggressively its a jerky old thing. In manual mode, with just a little experience it can be shifted seamlessly and it rev matches on downshift. The Porsche PDK , a true DSG is infinitely better in auto mode, and a little quicker in shifting. I would imagine the BMW DSG is similar.
m3mjw said:
Not long after i got mine (a week)i had all of the software updated. I alsways drive in manual and have it set to s5 all of the time. I must say i find it changes gear really well and is a lot less lumpy than i thought it was going to be after reading many comments before i got it. Not sure if this is due to it having new software. It is a 2006 car so pre facelift too
I also use S5. Perfect setting 
jon- said:
For me, single clutch automated manual boxes are fairly poor in auto but ace in manual, where as a dual clutch box is great in auto and boring in manual.
I have to say I'd be scared of getting a full DSG box as I'd worry I'd just end up driving around in auto all the time.
I tried a PDK for a few days, ( I live in a crowded city) and that is exactly what happened. OTOH, I don't get a lot of driving pleasure out of stop-and-go traffic, so using a manual is as much a chore as a pleasure. I await immediate expulsion from PH for that remark,I have to say I'd be scared of getting a full DSG box as I'd worry I'd just end up driving around in auto all the time.
What happens if you take your feet off all the pedals in an SMG car, say on a slight incline...does the car creep forward like an auto, stay still, or will it roll back like a manual car in neutral?
And, to inch forward in an SMG car, is it a case of being very light on the loud pedal
And, to inch forward in an SMG car, is it a case of being very light on the loud pedal
BUG4LIFE said:
What happens if you take your feet off all the pedals in an SMG car, say on a slight incline...does the car creep forward like an auto, stay still, or will it roll back like a manual car in neutral?
And, to inch forward in an SMG car, is it a case of being very light on the loud pedal
It will roll back as its a manual, but you do get a couple of seconds of 'hill hold' first. Yeah, you need to just dab the throttle to inc forward but be warned, too much of this 'inching' will fry your clutch / bearing. Stick it in N whenever you come to a stop to release the strain from the bearing.And, to inch forward in an SMG car, is it a case of being very light on the loud pedal
Eddie
ecain63 said:
BUG4LIFE said:
What happens if you take your feet off all the pedals in an SMG car, say on a slight incline...does the car creep forward like an auto, stay still, or will it roll back like a manual car in neutral?
And, to inch forward in an SMG car, is it a case of being very light on the loud pedal
It will roll back as its a manual, but you do get a couple of seconds of 'hill hold' first. Yeah, you need to just dab the throttle to inc forward but be warned, too much of this 'inching' will fry your clutch / bearing. Stick it in N whenever you come to a stop to release the strain from the bearing.And, to inch forward in an SMG car, is it a case of being very light on the loud pedal
Eddie
BUG4LIFE said:
ecain63 said:
BUG4LIFE said:
What happens if you take your feet off all the pedals in an SMG car, say on a slight incline...does the car creep forward like an auto, stay still, or will it roll back like a manual car in neutral?
And, to inch forward in an SMG car, is it a case of being very light on the loud pedal
It will roll back as its a manual, but you do get a couple of seconds of 'hill hold' first. Yeah, you need to just dab the throttle to inc forward but be warned, too much of this 'inching' will fry your clutch / bearing. Stick it in N whenever you come to a stop to release the strain from the bearing.And, to inch forward in an SMG car, is it a case of being very light on the loud pedal
Eddie
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