Educate me on SMG
Discussion
Someone ran into my A8 and wrote it off so I'm going to scratch a long awaited itch and buy an E46 M3.
I see that a lot of them are SMG equipped - my hankering is for a 'proper' manual - but I feel I should at least investigate the SMG option as there are so many about - and if so many people bought one there must be something going for them.
It will be my daily hack - and used to drive the 170 mile round trip to the office twice a week which includes some great fast DC with plenty of roundabouts and some less good sections of the M25 where I will be invariably stuck in traffic for 45 minutes on the way home.
My understanding is that this is a robotised manual - with the clutch being electoncially actuated from the paddles?
I also understand that it can be driven as an automatic? This could be handy when sat in motorway queues.
Can you rev match on downshifts with the SMG?
Are they any more costly/problematic than a standard 6-Speed manual?
Anything else i should know - or resources I should be consulting?
Thanks.
I see that a lot of them are SMG equipped - my hankering is for a 'proper' manual - but I feel I should at least investigate the SMG option as there are so many about - and if so many people bought one there must be something going for them.
It will be my daily hack - and used to drive the 170 mile round trip to the office twice a week which includes some great fast DC with plenty of roundabouts and some less good sections of the M25 where I will be invariably stuck in traffic for 45 minutes on the way home.
My understanding is that this is a robotised manual - with the clutch being electoncially actuated from the paddles?
I also understand that it can be driven as an automatic? This could be handy when sat in motorway queues.
Can you rev match on downshifts with the SMG?
Are they any more costly/problematic than a standard 6-Speed manual?
Anything else i should know - or resources I should be consulting?
Thanks.
Mr Gearchange said:
Someone ran into my A8 and wrote it off so I'm going to scratch a long awaited itch and buy an E46 M3.
I see that a lot of them are SMG equipped - my hankering is for a 'proper' manual - but I feel I should at least investigate the SMG option as there are so many about - and if so many people bought one there must be something going for them.
It will be my daily hack - and used to drive the 170 mile round trip to the office twice a week which includes some great fast DC with plenty of roundabouts and some less good sections of the M25 where I will be invariably stuck in traffic for 45 minutes on the way home.
My understanding is that this is a robotised manual - with the clutch being electoncially actuated from the paddles?
I also understand that it can be driven as an automatic? This could be handy when sat in motorway queues.
Can you rev match on downshifts with the SMG?
Are they any more costly/problematic than a standard 6-Speed manual?
Anything else i should know - or resources I should be consulting?
Thanks.
My only experience of SMG was in my E60 M5 & i believe that was the 3rd incarnation of SMG being SMGIII. As a manual box using paddles it was awesome & matched to the V10 was epic, although somewhat aggressive in the higher ferocity settings. As an Auto box it was shocking & as such i NEVER drove the car in Auto mode. Personally i found it tiresome quickly & never really gelled with the car.I see that a lot of them are SMG equipped - my hankering is for a 'proper' manual - but I feel I should at least investigate the SMG option as there are so many about - and if so many people bought one there must be something going for them.
It will be my daily hack - and used to drive the 170 mile round trip to the office twice a week which includes some great fast DC with plenty of roundabouts and some less good sections of the M25 where I will be invariably stuck in traffic for 45 minutes on the way home.
My understanding is that this is a robotised manual - with the clutch being electoncially actuated from the paddles?
I also understand that it can be driven as an automatic? This could be handy when sat in motorway queues.
Can you rev match on downshifts with the SMG?
Are they any more costly/problematic than a standard 6-Speed manual?
Anything else i should know - or resources I should be consulting?
Thanks.
The SMG clutches are a known weak point & many transmissions have failed as a result, although i'm again speaking about in the E60 M5 so perhaps it was better or longer lasting in the M3's.
I would try both and see what you prefer. I have had an E46 M3 which was manual and I currently have a e60 m5 and I really like the smg box, it takes a bit of getting used to but if I was to have another M3 I would definitely have one with a smg box ( as long as it has been well maintained)
As far as rev matching with down change the e60 does but not sure about the m3 with the smg ll box.
As far as rev matching with down change the e60 does but not sure about the m3 with the smg ll box.
I would try both and see what you prefer. I have had an E46 M3 which was manual and I currently have a e60 m5 and I really like the smg box, it takes a bit of getting used to but if I was to have another M3 I would definitely have one with a smg box ( as long as it has been well maintained)
As far as rev matching with down change the e60 does but not sure about the m3 with the smg ll box.
As far as rev matching with down change the e60 does but not sure about the m3 with the smg ll box.
Edited by M500 NTH on Thursday 31st December 01:08
Slightly OT, but I'll piggyback a few questions on to the thread if I may.
1. If you're in manual mode and coming to a stop, do you have to come down the gears on your own or will the car sense this and do it for you?
2.When it looks like your going to be at a stand still for a few minutes is it better for the car to put it in neutral?
3. When at a stand still in gear with the clutch disengaged and you want to set off, what determines the clutch engaging, number of revs?
4. What's the procedure for starting on shallow and steep inclines?
1. If you're in manual mode and coming to a stop, do you have to come down the gears on your own or will the car sense this and do it for you?
2.When it looks like your going to be at a stand still for a few minutes is it better for the car to put it in neutral?
3. When at a stand still in gear with the clutch disengaged and you want to set off, what determines the clutch engaging, number of revs?
4. What's the procedure for starting on shallow and steep inclines?
wolfracesonic said:
Slightly OT, but I'll piggyback a few questions on to the thread if I may.
1. If you're in manual mode and coming to a stop, do you have to come down the gears on your own or will the car sense this and do it for you?
- The car will change down itself quite seamlessly (e63 M6)
2.When it looks like your going to be at a stand still for a few minutes is it better for the car to put it in neutral?
- Don't think it really matters. If you do put it in manual, always press the brake pedal when putting it back in Drive, otherwise moving off can be quite abrupt.
3. When at a stand still in gear with the clutch disengaged and you want to set off, what determines the clutch engaging, number of revs?
- I believe so. Moving off should be perfectly smooth. Be sure to check for juddering when moving off when the car/clutch is warmed up.
4. What's the procedure for starting on shallow and steep inclines?
- The car has hill start assist which holds the brakes on for approx 2 seconds or until you start moving forward. This works very well in my experience. Not sure if this is present on e46 m3, but would imagine so.1. If you're in manual mode and coming to a stop, do you have to come down the gears on your own or will the car sense this and do it for you?
- The car will change down itself quite seamlessly (e63 M6)
2.When it looks like your going to be at a stand still for a few minutes is it better for the car to put it in neutral?
- Don't think it really matters. If you do put it in manual, always press the brake pedal when putting it back in Drive, otherwise moving off can be quite abrupt.
3. When at a stand still in gear with the clutch disengaged and you want to set off, what determines the clutch engaging, number of revs?
- I believe so. Moving off should be perfectly smooth. Be sure to check for juddering when moving off when the car/clutch is warmed up.
4. What's the procedure for starting on shallow and steep inclines?
wolfracesonic said:
Slightly OT, but I'll piggyback a few questions on to the thread if I may.
1. If you're in manual mode and coming to a stop, do you have to come down the gears on your own or will the car sense this and do it for you?
2.When it looks like your going to be at a stand still for a few minutes is it better for the car to put it in neutral?
3. When at a stand still in gear with the clutch disengaged and you want to set off, what determines the clutch engaging, number of revs?
4. What's the procedure for starting on shallow and steep inclines?
1) yes it will go down to 1st as a protection to the clutch. 1. If you're in manual mode and coming to a stop, do you have to come down the gears on your own or will the car sense this and do it for you?
2.When it looks like your going to be at a stand still for a few minutes is it better for the car to put it in neutral?
3. When at a stand still in gear with the clutch disengaged and you want to set off, what determines the clutch engaging, number of revs?
4. What's the procedure for starting on shallow and steep inclines?
2) clutch release bearing wear will increase if you don't put in neutral
3) engine speed/torque demand, clutch temp, grade
Just my opinion, but I would advise that a test drive will not really allow enough time for you to acclimatise to SMG enough to really allow you to get a decent feel for it.
When I got my E60 M5, it took a good hour to get it to click smoothly.
I think it helped that I am used to riding motor bikes without needing the clutch on upshifts and can also drive a manual car without using the clutch, changing both up and down, which give you a good feel for rev-matching.
In manual mode, you need to get used to lifting off the throttle slightly for every upshift. Otherwise, the change will always be jerky, although less so in higher gears.
Downshifts are always rev-matched by the system automatically
In auto mode, if you try to drive it like an auto, then it is horrible. However, if you sync lifting off the throttle slightly with the upshifts, then it can be very smooth. I tend to use D2, if I want auto, as it make the shifts a little faster, but doesn't hang onto the revs so much. I have found a slight glitch at lower revs, where the software will blip on upshifts if the revs drop too much when changing.
I you get a chance to test drive a car, get to spend some time watching the owner drive it first, to get a bit of a feel for shifting under SMG.
When it all comes together it can be a joy (but I still think I'd prefer a manual)!
When I got my E60 M5, it took a good hour to get it to click smoothly.
I think it helped that I am used to riding motor bikes without needing the clutch on upshifts and can also drive a manual car without using the clutch, changing both up and down, which give you a good feel for rev-matching.
In manual mode, you need to get used to lifting off the throttle slightly for every upshift. Otherwise, the change will always be jerky, although less so in higher gears.
Downshifts are always rev-matched by the system automatically
In auto mode, if you try to drive it like an auto, then it is horrible. However, if you sync lifting off the throttle slightly with the upshifts, then it can be very smooth. I tend to use D2, if I want auto, as it make the shifts a little faster, but doesn't hang onto the revs so much. I have found a slight glitch at lower revs, where the software will blip on upshifts if the revs drop too much when changing.
I you get a chance to test drive a car, get to spend some time watching the owner drive it first, to get a bit of a feel for shifting under SMG.
When it all comes together it can be a joy (but I still think I'd prefer a manual)!
Irish_Stu said:
- The car has hill start assist which holds the brakes on for approx 2 seconds or until you start moving forward. This works very well in my experience. Not sure if this is present on e46 m3, but would imagine so.
It is present, but I never used it. Handbrake did the job perfectly insteadIrish_Stu said:
wolfracesonic said:
Slightly OT, but I'll piggyback a few questions on to the thread if I may.
1. If you're in manual mode and coming to a stop, do you have to come down the gears on your own or will the car sense this and do it for you?
- The car will change down itself quite seamlessly (e63 M6)
2.When it looks like your going to be at a stand still for a few minutes is it better for the car to put it in neutral?
- Don't think it really matters. If you do put it in manual, always press the brake pedal when putting it back in Drive, otherwise moving off can be quite abrupt.
3. When at a stand still in gear with the clutch disengaged and you want to set off, what determines the clutch engaging, number of revs?
- I believe so. Moving off should be perfectly smooth. Be sure to check for juddering when moving off when the car/clutch is warmed up.
4. What's the procedure for starting on shallow and steep inclines?
- The car has hill start assist which holds the brakes on for approx 2 seconds or until you start moving forward. This works very well in my experience. Not sure if this is present on e46 m3, but would imagine so.1. If you're in manual mode and coming to a stop, do you have to come down the gears on your own or will the car sense this and do it for you?
- The car will change down itself quite seamlessly (e63 M6)
2.When it looks like your going to be at a stand still for a few minutes is it better for the car to put it in neutral?
- Don't think it really matters. If you do put it in manual, always press the brake pedal when putting it back in Drive, otherwise moving off can be quite abrupt.
3. When at a stand still in gear with the clutch disengaged and you want to set off, what determines the clutch engaging, number of revs?
- I believe so. Moving off should be perfectly smooth. Be sure to check for juddering when moving off when the car/clutch is warmed up.
4. What's the procedure for starting on shallow and steep inclines?
Mine had plenty of character on cold starts....bunnyhopping down the road with if driven off straight away and not let to warm up a bit. My have got fixed alter on as I took delivery of mine in 2002 and sold it in 2004. Great car though! Certainly miles better than its contemporaries of the time and I think a better car than its successors.
I have an E46 SMG and love it. It does take a week or so to get used to it but it is a manual box not an auto so auto mode is not like a proper slush box auto but it's great fun and great when stuck in traffic. As others have said try both but I wouldn't choose a manual over SMG unless it was going to be a pure track day car
I had one for a couple of years and I'll start by saying I want it back! Not for the SMG but the fact that it was a great car in brilliant condition when I let it go.
That being said though, I keep looking at those available now and can't bring myself to buy SMG again unless it's had a pump recently or is a great deal. If I was to buy SMG again, I'd simply assume I would need to have £1800 ready to fix the pump when, not if, it breaks. With that peace of mind, I could drive round and enjoy it. £1800 is a lot of servicing / BBK or beer whichever way you look at it. If such things don't bother you then yeah, it's an ok 'box when you get used to it but you need to accept its no DCT.
The other consideration is resale depending on how long you keep it for. SMG's will always sell slower and are valued slightly lower. The market is on the up and particularly for a decent manual.
That being said though, I keep looking at those available now and can't bring myself to buy SMG again unless it's had a pump recently or is a great deal. If I was to buy SMG again, I'd simply assume I would need to have £1800 ready to fix the pump when, not if, it breaks. With that peace of mind, I could drive round and enjoy it. £1800 is a lot of servicing / BBK or beer whichever way you look at it. If such things don't bother you then yeah, it's an ok 'box when you get used to it but you need to accept its no DCT.
The other consideration is resale depending on how long you keep it for. SMG's will always sell slower and are valued slightly lower. The market is on the up and particularly for a decent manual.
Mr Gearchange said:
Thanks chaps - PH invaluable as ever.
Think I'll stick with my first choice of a 3-pedal manual and continue the search
I honestly think you're making a mistake. I test drove several manual M3's but found the throw too long on them. I then owned a SMG II for 7 years. Coming from a 4 speed auto Supra it took me around 6 months to gel with the SMG but once I had it was sublime. Especially on the twisty national speed limit roads. Think I'll stick with my first choice of a 3-pedal manual and continue the search
I ran my car from 49 to 123k with no SMG issues whatsoever. Don't forget the SMG blips on downshifts and has the launch control and gearshift lights in the rev counter should you ever choose to use it.
By the sounds of your commute smg would be ideal.
SMG looses nothing when your being spirited.
But it is SOO much nicer in traffic.
On my surrey commute i drive mine almost exclusivly in automode. It works great. Better than some autobox's ive used thats for sure.
On the alps trips s5 or s6 on trackdays in manual mode and its brill. Lots of blips
If you were after a fun only car or track only car, i would go manual so there is a little more to do, but for a dual purpose car smg is a winner. Lets face it the m3 is the king of dual purpose so smg makes sense.
SMG looses nothing when your being spirited.
But it is SOO much nicer in traffic.
On my surrey commute i drive mine almost exclusivly in automode. It works great. Better than some autobox's ive used thats for sure.
On the alps trips s5 or s6 on trackdays in manual mode and its brill. Lots of blips

If you were after a fun only car or track only car, i would go manual so there is a little more to do, but for a dual purpose car smg is a winner. Lets face it the m3 is the king of dual purpose so smg makes sense.
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