Clubjazz - Honda Jazz & HR-V Forums

Honda Jazz, HR-V & Hybrid Forums => Honda Jazz Mk3 2015 - 2020 => Topic started by: ivan on November 22, 2020, 10:17:09 AM

Title: cvt comparison version 2 and 3
Post by: ivan on November 22, 2020, 10:17:09 AM
I recently traded my 2012 Jazz for a 2020 ver 3.  but am disappointed with the way the cvt responds..  Do I have a problem ?  If I am cruising along at 70mph at 2300rpm and ease my foot down for a small up slope.. the revs increase to 3000 or even 4000rpm..  If I have cruse control on,  and a small incline happens,  the revs shoot straight up to 5200rpm and the wife says.. what are you doing?..  Is it possible to get Honda to back off the cvt so I can say use 25% throttle without revs jumping up.. or did I just get spoiled by my version 2 ?
Title: Re: cvt comparison version 2 and 3
Post by: trebor1652 on November 22, 2020, 11:55:08 AM
Yes it's annoying.
I have started to turn the traction control off and this does help.

Sent from my moto g(6) using Tapatalk

Title: Re: cvt comparison version 2 and 3
Post by: equaliser on November 22, 2020, 11:55:22 AM
Hi and Welcome!
No, you don't have a problem, it is a characteristic of the engine which runs in Atkinson cycle below 3000rpm to save fuel but has less torque than the previous engine at these lower rpms. Once above 3000rpm it switches to the Otto cycle and develops full power and torque. If your engine has very low mileage the effect of the Atkinson cycle is more pronounced, it definitely improves with more miles.

I've improved the behaviour by using higher octane petrol (98 RON), using this the engine will pull much better at lower rpm. Hills around me normally require the engine running at 3000rpm but with the higher octane petrol it can take the same hills at 2000rpm. Not everyone will agree but it works for me.
Title: Re: cvt comparison version 2 and 3
Post by: Happyarry on November 22, 2020, 02:24:20 PM
Haven't tried putting my foot down at 70mph but I do know at lower speeds the paddle shift just drops it a "gear" giving a seamless boost and without the raucous sound you can get by overworking the right foot. Nice for overtaking or joining traffic.

Harry
Title: Re: cvt comparison version 2 and 3
Post by: trebor1652 on November 22, 2020, 03:08:42 PM
Yes it's annoying.
I have started to turn the traction control off and this does help.

Sent from my moto g(6) using Tapatalk
The other thing to do is to click it into S mode before you enter the incline and the car will climb much better.

Sent from my moto g(6) using Tapatalk

Title: Re: cvt comparison version 2 and 3
Post by: ivan on November 22, 2020, 05:49:30 PM
It is not that I haven't driven a JAZZ cvt for 8 years already..  it is just that I feel it should not gear down till at least 25% throttle opening..  The paddle momentarily shifts it higher but immediately slides back to 3000rpm on a slight upgrade.. even though I have a light pressure on the throttle..  It only has 4000m on the clock.. maybe it will improve..
Title: Re: cvt comparison version 2 and 3
Post by: equaliser on November 22, 2020, 06:25:13 PM
It is not that I haven't driven a JAZZ cvt for 8 years already..  it is just that I feel it should not gear down till at least 25% throttle opening..  The paddle momentarily shifts it higher but immediately slides back to 3000rpm on a slight upgrade.. even though I have a light pressure on the throttle..  It only has 4000m on the clock.. maybe it will improve..

It will definitely improve with mileage and you'll also learn to adjust to its characteristics over time, I know I did and it doesn't bother me any more.
Title: Re: cvt comparison version 2 and 3
Post by: embee on December 01, 2020, 09:42:18 PM
One way I've found to calm the cruise control down a bit is to put it into "manual". Select "S" on the gear lever and then use one of the +/- buttons and it will go into a "manual" mode and show a small "m" in the display with the big S, and the ratio you are in.
It will stay in this ratio pretty much until you either slow down too much or you use the +/- buttons. I've tried it with cruise and it still stays in the "Sm" mode and seems to keep the ratio selected.
I confess I haven't explored the envelope of what it will and won't do in this setting, I'm still learning how it behaves, but "Sm" is very useful.

You do have to remember it is in this when you come to a stop and then pull away again, you have to change gear using the paddles or it just revs up in first, consequently I've got into the habit of slipping it into D before I come to a stop, and once on the go again I reset it to Sm as and when convenient or appropriate.
Play with it and see what you think.
Title: Re: cvt comparison version 2 and 3
Post by: John Ratsey on December 03, 2020, 11:53:58 AM
I only kept a 2015 Mk 3 CVT for one year because I didn't like the way that modest pressure on the accelerator pedal resulted in a substantial increase in the engine revs. I thought that Honda had modified this behaviour as part of the Mk 3 mid-life refresh but the underlying problem is, as already noted, the Atkinson cycle mode adds efficiency but doesn't provide much torque. Honda had probably worked out that having a burst of acceleration at higher revs before dropping back into the efficient mode was best for overall fuel economy but didn't properly consider how these bursts of engine activity would impact on the driver who wants a progressive increase.
Title: Re: cvt comparison version 2 and 3
Post by: equaliser on December 04, 2020, 03:28:43 PM
I only kept a 2015 Mk 3 CVT for one year because I didn't like the way that modest pressure on the accelerator pedal resulted in a substantial increase in the engine revs. I thought that Honda had modified this behaviour as part of the Mk 3 mid-life refresh but the underlying problem is, as already noted, the Atkinson cycle mode adds efficiency but doesn't provide much torque. Honda had probably worked out that having a burst of acceleration at higher revs before dropping back into the efficient mode was best for overall fuel economy but didn't properly consider how these bursts of engine activity would impact on the driver who wants a progressive increase.

After a few thousand miles that behaviour calms right down. When I was test driving 2-3 year old Jazz models I noticed the low mileage ones behaved as you described which I why I went for one with more miles as it was was much better at holding the revs down and not screaming at the slightest throttle pressure. The engine is also smoother and quieter in operation with more miles, the low mileage engines sounded vocal and gruff!
Title: Re: cvt comparison version 2 and 3
Post by: embee on December 04, 2020, 05:48:54 PM
I agree with the observation about the engine improving. My car is still very low miles, but when I got it there was 1500mls on it at 2yrs old. One lady owner, I'm pretty sure it had never ever been revved, probably hardly ever been above 50mph. It was a bit raucous when revved.
I have been progressively working it harder, I regularly use manual mode and hold it at 4500-5000rpm in lower ratios while on the motorway for a few minutes at a time. I also use manual to hold it in higher gears on inclines/hills to use full throttle at lower revs (and as we all know, nothing much happens).
It's definitely improving it, getting smoother and quieter generally. They need working through the full rev and load range to settle in. I reckon 20k miles should sort it properly.
Title: Re: cvt comparison version 2 and 3
Post by: Happyarry on December 05, 2020, 09:35:34 AM
All interesting stuff, remember from being on the Skoda Forum very similar threads to this relating to their dual clutch gearbox but in their case the gearbox was said to be slow to respond.
I know the boxes are entirely different but the similarities are that the advice given was the same as on here. "It will improve over time" and it did.

In their case they said the gearbox was 'intelligent' and learned driver input.

I can't help thinking most of the improvement comes from drivers getting used to a new system and learning how to use it. It seems the Mk111 gearbox is proving to be different to earlier models and causing some users problems while others are perfectly at ease with it?
Title: Re: cvt comparison version 2 and 3
Post by: Downsizer on December 05, 2020, 06:58:12 PM
I can't help thinking most of the improvement comes from drivers getting used to a new system and learning how to use it. It seems the Mk111 gearbox is proving to be different to earlier models and causing some users problems while others are perfectly at ease with it?
I didn't have CVT on my Mk 2 so I can't compare, but the Mk 3 engine is certainly different, and tuned for economy below 3000 rpm (see previous posts).  I have not had a problem with the CVT and am delighted with it.  I have not noticed any change over 4 years, but almost all my driving is below 3000 rpm.  I only exceed that when overtaking or accelerating in a hurry (e.g. entering a busy roundabout) or on steep hills (which are very rare in East Anglia), and also occasionally when using the paddles to downshift for engine braking.  I plan to keep the car up to at least 70,000 miles.
Title: Re: cvt comparison version 2 and 3
Post by: ivan on December 16, 2020, 03:24:33 PM
thank you for the pointers...  I am going to Pretoria for Christmas...  650kms, each way, so will try these tricks and see how it goes.. my previous Jazz gave me 4.9l/100 on a round trip..  this one did 5.2l/100 on the previous trip.. normally travelling at 120km/hr.. 3 up.. My previous 2 Hondas both loosened up with about 100km on the clock...