End of first week with Shifty - is the romance still there?

Oh dear, oh dear. I have had to have words with Shifty about its bad habits but I think it is playing deaf at the moment.

So what's up? Well, like all relationships communication is the key to successful partnerships and the big problem with Shifty is that it's tricky to communicate my driving wishes. OK, sure if I make extreme actions it reacts dramatically but day-to-today it's hard to live with Shifty's indifference and, at times, plain stubborness.

You see dear reader, Shifty seems to be stuck in its ways. It seems to me that there are two zones of operation that Shifty can choose: zone one - clean, green, eco-friendly, and zone two - frantic, we're in a race and who cares about the environment. However, the reality is that living in this World it has to be a compromise between the two.

Shifty in Zone One

This is where Shifty lives. It yearns forever to be in zone one and just as soon as it can it will go back to it.

I can report that in zone one the car is very efficient, reasonably quiet and quite able to make progress. I have seen values of about 56 miles per imperial gallon on a regular basis. However I have found in semi-urban and out-of-town driving that this zone is completely incompatible with other road users. In fact to drive this way would cause most, even reasonably tolerant drivers, a degree of annoyance.

Note, however, at times when the road is clear of traffic, the i-SHIFT is nice to drive. It gives an almost CVT like low-rev response. OK. Let's rephrase that to: as best can be expected with so few gears to choose from.

If you test drive an i-SHIFT and usually drive a CVT based car then it is not wise to use quiet, gently hilly, relatively slow speed roads as this will mislead you into thinking that the behaviour is quite close to your CVT. Choose major roads in rush hour, particularly entering and leaving the town limits.

Constant speed crusing above 40MPH approximately matches the CVT in terms of engine RPM and engine derived noise. The slight transmission whine of CVT is absent although I never really found it intrusive with our previous two Jazz 1.4 i-DSI SE CVT7 cars. Dual-carriageway and motorway cruising is better in the i-SHIFT than the CVT however with regard to overtaking. The i-SHIFT seems more able to pass traffic perhaps due to the more powerful engine and higher torque and power rev ranges.

Note also the i-SHIFT transmission has the same final drive ratio as the manual Jazz and shares the same 3, 4 and 5th gear ratios. The i-SHIFT also has an additional 6th gear which is absent from the manual Jazz giving the i-SHIFT a much lower reving, quieter high-speed cruise performance and even better fuel efficiency.

Shifty in Zone Two

In this zone, I would say Shifty performs just like any Euro 5 emission compliant, 1.4, litre, 16 valve petrol engined car would when driven in a "sporty" way. The major characteristic is an obvious feeling of torque from 3000 RPM to 4500 RPM with good acceleration that is slightly below average for this class of car.

Continuous zone two driving however would be seen by most other road users as aggressive. Also the higher acceleration and deceleration forces that must be adopted to keep the i-SHIFT transmission from jumping back to zone one would be pretty unbearable to passengers for anything other than the shortest of trips. Additionally I would assume there would be a large drop in fuel efficiency and higher wear on the engine and running gear.

The previous 1.4 litre CVT Jazz could not really match the performance required in this zone. If an attempt was made to drive sportily, performance would be close to a 1.0 litre, 16-valve multi-point fuel injected engined car. The i-DSI 8-valve twin-spark plug per cylinder engine had less torque delivery than the iVTEC engine, peaking about 2800RPM. My own driving experience of the CVT showed that gradual throttle control was best to maximise acceleration performance. Enthuastic throttle use caused the CVT to let the engine rev to high RPMs and as a result did not deliver the best torque. I think this behaviour was one that caused many test drivers to be put off the CVT. Shame really, since the CVT had very smooth acceleration if driven to maintain low engine revs rather than a racing engine.

How can it be in these "Zones"?

First of all this zone idea is my own thinking based on 400 miles of i-SHIFT driving so far. There isn't a Zone button to push! In fact the decision by Shifty to be in Zone 1 or 2 comes down to how assertively I move the throttle.

The use of kickdown (suddenly pressing the throttle down) will cause i-SHIFT to change down one or more gears. More immediate acceleration is then achievable. This is because i-SHIFT seems to choose a gear low enough to change the engine speed to the start of the engine's best torque range. This lower gear is then maintained for longer than would be the case for zone 1. The thinking, I guess, is to ensure that i-SHIFT doesn't interfere in any overtaking that the driver might be doing by keeping the lower gear choice for a while even if the driver backs off their acceleration.

This is what I think of as Zone 2. It can be short-lived - if the throttle actions after the kickdown are not suggestive of continuing demands for higher speeds, or the engine is not now providing a level of engine braking, then i-SHIFT will change up to the highest possible gear. This could be 1, 2 or 3 gears above the current i-SHIFT kickdown one. It can also be longer lived if throttle use continues to be aggressive and the lower gear choice is providing maximum acceleration or engine braking.

The downside of this Zone 2 behaviour is you can get inadvertantly stuck in it. To understand this, you need to think about engine braking. Engine braking is caused by choosing a lower gear and then not giving an increased throttle position to match the higher engine revs of that lower gear. I.e you are not cruising in this lower gear but instead are decelerating. I think this fools i-SHIFT into thinking you are still in the maneouver that was initiated by the kickdown so it does not change up. To overcome this you need to learn to apply enough throttle to be neither decelerating nor accelerating in the gear. Once i-SHIFT detects that, it will change to the lowest gear that could achieve this cruising more efficiently and thus return back to zone 1 behaviour.

My advice is to avoid kickdown and switch to manual operation during the overtaking maneouver and return to automatic operation once it is complete. Alternatively you can aim to become sensitive to the needs of i-SHIFT and apply enough throttle to avoid the decleration that prevents i-SHIFT from returning to higher gear operation.

Introducing the Shared Zone

So if zone one and two are inappropriate for most drivers, what's an i-SHIFT owner to do? Well the answer is you need to be the "intelligent" part of the i-SHIFT name! Instead of letting the transmission make predictable mistakes you need to step in and make the appropriate changes for it.

Suggestions:

For my regular commute I have identified fifteen areas on my journey that I need to step in and make the appropriate gear changes. For the remainder of the 80 mile round-trip the i-SHIFT makes reasonable judgments. I recommend if you're an i-SHIFT owner that you do the same. I also have built up some rules of thumb for situations that I know that I will have to take over.

These are:

• Gradual speed decrease from a speed above 35MPH prior to entering an urban limit where a 30MPH limit is in force. There is a tendency for i-SHIFT to stay in a high gear and it's then easy to inadvertantly exceed the limit. 
• Without me interfering, Shifty will be in 5th gear at 30MPH. (The i-VTEC engine is designed to be able to cope with this very low rpm without damage and I can report there is no labouring of the engine that would cause damage - I believe the variable valve timing of the engine assists here.)
  
  To reduce accidental increase in speed I switch to manual mode, change to 4th gear and switch back to automatic control. Unless the road speed goes above 33-35 MPH the i-SHIFT won't switch back to 5th gear.
• An alternative approach is to stay in automatic mode. Decrease to 25MPH - Shifty changes to 4th. Increase speed to 30MPH. No upward change will occur until above 33-35MPH.
• 
  Starting off from rest on a decent in automatic keeps transmission in 1st gear unless the road flattens out. You could argue that Shifty is correct to do this. After all the maximum engine braking on steep descent would be by using 1st gear. However, most drivers, mainly to reduce drawing attention to themselves by making excessive noise and to reduce wear and tear due to the high reving engine (easily 3000 RPM in 1st on descent) would choose 2nd and use regular dabs on the footbrake to control speed. This approach can also be achieved using the i-SHIFT "deep snow", 2nd gear start behaviour.
• With the car at rest, ready to move off with the gear selector showing A1, tap the up-shift + floor shift or the + steering wheel paddle. 2 will show in the display (i.e. manual 2). Move off. The transmission will now remain in 2nd gear until the first time the road speed goes above 10MPH. After this has occured then, if  speed drops below 10MPH again, i-SHIFT will change into 1st gear again. After the descent use the gear-shift to switch back to automatic.
• Leaving a 30MPH limt. There is a tendency for i-SHIFT to change into 5th at 32 - 35MPH and then to 6th at 37-39MPH. This really reduces acceleration effectiveness and tends to inconvenience following traffic. I believe for most people this is a major dislike of the car. Two approaches to overcome this:
• If you stay in i-SHIFT auto mode, then you must make a smooth but assertive increasing throttle movement. Not as fast as would generate a kickdown but enough and to hint to i-SHIFT that a higher gear at this moment would not be appropriate If your acceleration request is too gentle a change from 4th to 5th will occur at 32-35MPH and 5th to 6th at 37-39MPH. If your request is too enthusiastic i-SHIFT will change down to 3rd.
  The key to i-SHIFT living is to balance cruising, against progessive acceleration, against enthusiastic acceleration.  This is a driving skill and over time you learn to match throttle movement with increasing engine speed to ensure neither upward or downward inappropriate changes are made.
• If you prefer to use manual mode to prevent the upshift, then at the moment of reaching the end of the limit, switch to manual, accelerate in 4th (from 30MPH) and when you reach crusing speed, say 45/50 MPH switch to auto again. Do this and you will not feel like you're holding up following traffic.
• Exiting roundabouts often seems confuse i-SHIFT. It seems to change to a higher gear at a very inappropriate time. This can be disconcerting because acceleration will be poorer. Use the same workaround as for exiting 30MPH speed limits: either use manual mode prior to exiting the roundabout so you can fully control the gear selection, or progressively accelerate in such a way that i-SHIFT does not change up too early. I tend to use manual mode at roundabouts because the exits tend to be too sharp to make sufficient acceleration to stay in a lower gear.
• Tendency to stay in 1st gear too long when accelerating from rest at traffic lights, junctions, etc. This really is something that CVT users will be sensitive to since they are used to hearing reving engines! In fact the i-SHIFT cannot make an upward change to 2nd below 10MPH so the reving engine noise is just something you have to get used to. It is no different to that experienced by manual transmission drivers. Avoid using the snow-start technique - starting off from rest in 2nd in manual mode then switching to auto later. When using 2nd gear starting i-SHIFT has to slip the clutch which will cause premature wearing.

I can't be bothered with this sharing responsibility malarky.

If you don't want to help the i-SHIFT controller, then you just stay in manual mode for all operations. The downside of this is that you miss out on some of the savings in efficiency brought by allowing i-SHIFT to work most of the time. It's true, sometimes i-SHIFT can be annoying and makes some silly mistakes but it also never gets tired watching what's going on with engine speed and gear selection; usually it won't hold on to lower gears too long - this is where fuel and emissions savings can be had. Also you do get a whole extra gear 6th gear in the i-SHIFT that the manual car does not have.

My Recommendations

If you've got an i-SHIFT then I recommend you share the gear changing responsibilities and not expect i-SHIFT to see the road ahead, or guess what you plan to do. Instead, if what is going to happen is likely to be unexpected by i-SHIFT then you need to switch to manual mode and make the changes to help it out. If you're new to i-SHIFT then make a real effort to try to learn how to use the throttle alone to prevent i-SHIFT from changing gear at the wrong moment for you. It should become second nature with practice.

And drive responsibly! If you know you're going to be in a situation where you absolutely need to be in control of gear changing - i.e. if an incorrect automatic change is likely to cause you an issue at that moment - then change to manual mode and do gear changes yourself until the moment passes.

And, with everything said, yes I still do love the our new Jazz i-SHIFT. It's not at all like the wonderfully driveable, clever CVT that's true. It can never be. In fact I now fully appreciate why having as many "gears" a CVT has makes sure that it has none of the problems mentioned about the i-SHIFT.

Let's hope Honda is brave and ignores the motoring journalists' opinion about CVT over-reving behaviour and brings the Honda Jazz hybrid with a CVT transmission option to the UK. If they do, it won't be long before we'll be driving one. Until then, I'll have to learn to share gear changing responsibility.