Queries about the Mk3 CVT compared to the Mk1 CVT

[guest5679]

Returning to the original subject matter of this thread …!

Yesterday, I had a test drive in a Mk3 EX CVT Jazz.  In summary, I was not impressed by the performance of the CVT compared to that on my Mk1 Jazz … but I might have missed a trick!

When I pull away from stationary in my Mk1 CVT Jazz, I can easily achieve a smooth, quiet, comfortable and yet reasonable acceleration without revving the engine.  In fact, I never accelerate fast unless I have to (e.g. to overtake a slow moving vehicle on a single carriageway), but I don’t dawdle either.

During the test drive, I tried to pull away from stationary in the same way that I do on my Mk1 CVT Jazz and I can only describe the performance of the CVT as sluggish.  Only by putting my foot further down on the accelerator pedal was I able to get the CVT to respond and achieve a reasonable acceleration.  But this was at the expense of revving the engine, resulting in the inevitable increased engine noise.

I can now begin to understand comments from critics like, “you put your foot on the accelerator pedal … and nothing happens”!  On my Mk1 CVT Jazz, the CVT is so responsive to changes in pressure on the accelerator pedal, but this does not appear to be the case on the Mk3.

A few years ago, I did have a test drive in a Mk2 CVT Jazz, and I didn’t notice any difference in the behaviour between the Mk1 CVT and the Mk2 CVT.  So, the difference appears to have come with the Mk3 CVT.  (In fact, overall, I didn’t find any major benefit in the Mk2 Jazz compared to the Mk1 Jazz, which is why I decided to keep my Mk1 Jazz at that time.)   

I mentioned all this to the sales rep afterwards.  The main argument he used in defence of the Mk3 CVT was that the Drive position of the gear lever is really an “Eco” position.  In this position, the CVT system tries to minimise fuel consumption and emissions.  He added that I should have tried the gear lever in the S position, which he believes is the more “normal Drive” position.  He claimed that the CVT would have been more responsive in that position.  Can anyone confirm the sales rep’s claim?

Did I miss a trick by not trying the gear lever in the S position?  For my Mk1 Jazz, the handbook describes the D position as the normal driving position and the S position as “Second (S) – Selecting Second shifts the transmission into a lower range of ratios for better acceleration and increased engine braking.”  What does the Mk3 Jazz handbook say about the S position in relation to the D(rive) position?

[edam]

Returning to the original subject matter of this thread …!

When I pull away from stationary in my Mk1 CVT Jazz, I can easily achieve a smooth, quiet, comfortable and yet reasonable acceleration without revving the engine.  In fact, I never accelerate fast unless I have to (e.g. to overtake a slow moving vehicle on a single carriageway), but I don’t dawdle

I drive my MK2 the same way.
On a long straight road with 4 sets of lights  and speed cameras I can keep the revs at 1500 rpm and keep up with the traffic.
After a short test drive of a Mk3 I'm wondering could it do the same.
My service is due soon and may try to get a Mk3 loan car and drive it down the same road. Could be interesting

[John Ratsey]

One needs to have a very tender touch with the right foot to avoid the engine temporarily revving above 1500 rpm when accelerating but the revs will quickly drop back once the car is up to speed. I find 2000 or even 2500 rpm to be barely audible (but any engine noise is more noticeable at lower speeds when other noises are less). I would consider the need to raise the revs to be a feature of the car and the consequence of the lower end of the engine's speed range being designed for economy. Honda may have even worked out that it's more fuel-efficient to have a quick burst of higher revs than keep the engine speed lower.

Regarding the use of S mode, I attach the relevant pages of the handbook. I interpret S mode as being for manual control of the gear shifts using the paddles rather than a different set of rules for engine operation. My old hybrid had a green ECO button but the new car doesn't.



[attachment deleted by admin]

[guest5679]

Thank you John for taking the trouble to scan the relevant pages from the new handbook.

It appears to me that the intended use of the S position of the gear lever is basically the same as that on the Mk1 CVT Jazz.  It is for speed merchants who want to be quick off the block and reach their desired speed in the minimum amount of time.  And, to do that, the CVT has to remain in the lower range of ratios for longer.  I don't think my sales rep is correct in his assessment of the S position.

I should perhaps clarify the following sentence which I wrote in my previous post: "When I pull away from stationary in my Mk1 CVT Jazz, I can easily achieve a smooth, quiet, comfortable and yet reasonable acceleration without revving the engine.".  Of course, as the car accelerates from stationary, the engine does rev as indicated by the rpm dial.  My use of the word "quiet" was really stating that this revving is not audible and that, once my intended speed is reached (say 30 mph) and I ease off the accelerator pedal, there is little of no difference in the engine noise subsequently.  I couldn't achieve this on my test drive of the Mk3 EX CVT Jazz; the engine revving was always audible.

[VicW]

The 'S' or 'Sport' position is very useful for overtaking or quick get-aways.
Select  'S' and open the throttle wide and the transmission will work in the way it is designed to. The overall gear ratios are lowered and the effective change up point is raised but even then it gets nowhere the red line.
When the overtaking (or quick get-away) manoeuvre is complete then knock the selector back to 'D'.
The increased performance is quite marked.

Vic.   

[guest5679]

Yes, I was aware that the S position is sometimes referred to as the "Sport" position.  But, in the Mk1 Jazz handbook, it is referred to as the "Second" position.

Personally, I've never needed to use the S position.  If I overtake a slow moving vehicle on a single carriageway, I have plenty of power if I kick down with the gear lever remaining in the D position.

I'm not an ultimate performance seeker.

[John Ratsey]

It's worthwhile (re)reading Honda UK's press release for the new Jazz at http://hondanews.eu/eu/en/cars/media/pressreleases/58052/2015-honda-jazz. I think the "improved driveability" means trying to improve the likelihood of the engine being in the appropriate speed range to deliver the expected response. Hence the engine briefly speeding up to 2500 to 3000 when pulling away. The revs will quickly drop back if rapid acceleration is not needed but this burst of revs puts the car into a position where it can accelerate rapidly if needed. My Jazz is set to give a short beep whenever it accelerates through 30 mph which I find useful because it is very easy to accelerate beyond the speed limit when pulling away from the lights or roundabouts.

My conclusion, after a month of Mk 3 CVT ownership, is that the willingness of the engine to rev (and emit a slightly sporty growl) is a positive feature and not a failing. That the CVT gives better mpg than the manual gearbox in the official urban driving test suggests that Honda have given significant thought to the best way for the gearboc to behave when accelerating.

[trebor1652]

You can always use the paddles on the mk3. Unlike the mk1 7 speed is there to use without having to press the 7 speed button. I find the mk3 responds better to the paddle in D than the kick town.
It does drive more like the mk1 in S. I have yet to try 7 speed mode in S.
And yes I think D is economy mode.

Sent from my XT1039 using Tapatalk

[guest5679]

You can always use the paddles on the mk3.

IMHO, using the paddles defeats the whole objective of having an automatic gear box.  I don't want to have to be concerned with gears and ratios.  I just want to put my foot on the accelerator pedal and go.

It does drive more like the mk1 in S.

Interesting feedback!  Thank you.  Sounds like I should ask to try it.  But I think I would be nervous using the S position all the time when Honda specifically state that the D position is for normal driving.

[guest5679]

It's worthwhile (re)reading Honda UK's press release for the new Jazz at ... My Jazz is set to give a short beep whenever it accelerates through 30 mph ...

Some food for thought there.  Thank you.

As it happens, on the demonstrator car I used for my test drive, a previous driver had also set the short beep at 30 mph and left it on.  The beeps became very irritating once the we had left the built up area and were stopping and starting at junctions and roundabouts.  And I didn't know how to switch them off!

[guest5864]

I only drive automatic cars and have done so for the last 35 years or so, so I was very interested in this topic. CVTs I have driven in the past have all had the same kind of quality, i.e smooth, seamless acceleration often making very good and rapid progress with little engine rpms. Last year I drove the previous model Jazz for a day while my brand new Civic was back at the main dealer to find out why the air conditioning didn't work, turns out it had left the factory with no refrigerant in the system, but that's another story.

Back to the previous model Jazz. The CVT performed exactly as I expected, you could move away from rest with no more than 1500 rpm and experience very rapid and completely smooth acceleration, frankly, it was a joy to drive. It was with MUCH eager anticipation that I had the use of a brand new Jazz last week when my Civic was in for a service.

I can confirm that the CVT in the new Jazz behaves completely different. Move off from rest with even a moderate requirement for acceleration causes the rpm to rise to a very noisy 3000 and stay there until the car reaches some speed or you ease off the pedal, then, there is a noticeable gear change into a higher gear, and as you progress, there are other noticeable gear shifts. When proceeding along my normal route to town which includes a road with some long, but fairly shallow up and down hill stretches, going up a very modest incline at 50mph which I usually do, resulted in the CVT dropping down and sending the engine revs again up to 3000. It did this at every opportunity.

I wanted to take it on the M4 and there is a fast feeder road leading up to it at which you have to stop for a roundabout. I noticed many pronounced gear changes during acceleration up to about 60mph and them upon slowing down to stop the CVT dropped down with the effect of causing pronounced engine breaking.

Once on the motorway it got up to 70mph very easily, but again, there are definite gear shifts, not the totally smooth progress as in the previous model Jazz. At 70mph the engine rpm are just over 2200, so very relaxing and it was really nice to cruise in, however any need to overtake will send the engine revs soaring. 

Some other points I noted. Move off from rest is not quick, there is a definite hesitancy. This is something one would probably get accustomed to, but I didn't like it. Slowing down to a stop did occasionally cause the transmission the jerk somewhat. The first thing I do in any car that has it is deactivate that ridiculous stop/start system so I can't comment on how that works, but all I know is that when I'm at a mega busy roundabout or junction and I need to be able to go in a split second, I don't want to be sitting there in a car with the engine switched off, and similarly when maneuvering to park and the engine is on/off, on/off it's just crazy!

So to sum up, I did not like the new CVT at all. Honda have engineered in artificial gear shifts to make the transmission behave more like a conventional auto box, but in doing so have ruined the smoothness that made CVTs so great and effortlessly driveable. The new Jazz as car is actually really nice, and I would have definitely gone for one for my next car, but with this CVT, no way.

[LJs JAZZ]

hello, Just a general point about a test drive in a brand new car. How many miles are there on the clock? When I changed from my Mk 1 cvt to a brand new Mk 2 I was rather disappointed in the performance. You are not going to get decent performance from a brand new engine. After about 7000 miles things improved no end, without any servicing or adjustments the engine seemed to gain some extra oomph!!

[guest5679]

I only drive automatic cars and have done so for the last 35 years or so, ... but with this CVT, no way.

Very interesting feedback.  Thank you.  However, when I had a test drive in a Mk3 CVT Jazz, I didn’t notice any perceptible gear changes.  My main issue was the sluggish and unresponsive nature of the Mk3 CVT compared to the Mk1 CVT.

I have the following comments.

In a previous post in this thread, I explained that the Mk1 CVT has three modes of transmission.  Mode 1 is purely automatic.  Mode 2 is 7 speed automatic with the simulated current gear shown in the display.  Mode 3 is manual gear changing using the +/- paddles.  If you drive a Mk1 CVT Jazz in Mode 2, you do perceive the simulated gear changes.  I’m left wondering whether the Mk3 CVT Jazz also has three modes of transmission and that, unintentionally, you were driving it in Mode 2 instead of Mode 1?

The other thing that comes to mind is that, if there are indeed perceptible gear changes in Mode 1 of the Mk3 CVT (which I failed to notice for whatever reason), it might go some way to explaining a sentence in Section 4 of:

http://hondanews.eu/gb/en/cars/media/pressreleases/58326/2015-jazz

I quote the sentence:

“The CVT’s driveability is given a more natural ‘multi-gear’ feel through the use of new control software exclusive to Europe which simulates seven speeds and provides optimised gear change mapping.”

I am still perplexed as to why Honda believe that a ‘multi-gear’ feel is natural.  And, why would anyone who has enjoyed the benefits of the beautifully smooth and seamless acceleration of a Mk1/Mk2 CVT want a ‘multi-gear’ feel?

[trebor1652]

Well I have done about 1600 miles and not noticed any 'gear change' on my CVT.
Unlike the mk1 you do not have the 7 speed button.
I have only tried this in D mode, to get the car to accelerate a little quicker than kick down, try the down paddle the revs pick up and the gear number is displayed on the dash.
It will then go back to D mode by itself once the speed has increased.

Sent from my XT1039 using Tapatalk

[John Ratsey]

With 2,000 miles on the clock I don't notice the engine revving as much as when it was new. This could be a case of me being more accustomed to the car's behaviour, or it has adapted to my driving style. Or maybe as the miles get clocked up the software allows a bit more load to be put on the engine.

The Mk 3 does have its preferred speed ranges although these seem to be less well defined than on the Mk 2 CVT. There's a lot of unseen thinking going on which affects which logical gear the car should be in and this thinking is probably easier by having well defined and analysed operating ranges.