Lean burn for Japanese spec CVT cars?

[Ccaptain24]

Hi,

I am well aware that US spec CVT cars do not have lean burn. What about home (Japan) market cars? There are two main reasons I ask.

The first is that on my car from autostop once rolling at about 1/2 assist/10 mph/25 mpg I can ease back on the gas, the IMA drops back to 1/4, the mpg jumps to 50 and the car continues to accelerate.

The second is that at 65 mph I can ease back very gently on the gas and the FCD strip suddenly jumps to 70/75 mpg. It will continue like this for about two minutes then the display drops to 50 mpg and the car surges forward. I then have to repeat this trick to get the FCD back to 70/75 mpg.

Other observations are that in general main road and town driving I get about 62.5 mpg and on a 197 mile motorway run I achieved 75 mpg (US galls) at an averge speed of 54 mph. (This journey includes some long motorway grades and three short steep climbs). I am aware that my LMPG is about right for a CVT car but would point out that 80% of my driving is night time motorway work at 65/75 mph with few opportunities to slipstream and sacrificing economy for time. (It still burns 40% less petrol than my smart did on the same run).

What would really clinch it is if there is an easily identifiable component unique to lean burn cars somewhere. Is anyone able to suggest such an item I could check for please?

Em

[Insightful Trekker]

Reads like lean burn with a NOx purge cycle to me.

IIRC Japan CVT's did have lean burn built in. It was identified as such and discussed in a thread here a few years back.

The primary lean burn system is built into the PCM's logic. I don't remember if non lean burn CVT's have one, but a 5 wire O2 sensor IS a requirement for lean burn.

HTH!

[Ccaptain24]

Thank you John,

That is rather what I was hoping to hear. Where is the O2 sensor? I will check it tomorrow (today) weather permitting. We have a tremendous thunderstorm right now!

Em

[Insightful Trekker]

Well don't thank me yet.

My memory has cleared a bit and on the 02's and up the LAF was redesigned to only require 4 wires.

But...all my info is North American market based. Its not uncommon for Japan only models to have differences of this caliber.

Me thinks another Japan import to the UK Insighter will need to have the final say so. Unless you read or speak Japanese, then you can go to the source.

Also see this concurrent thread here:

US CVT lean burn conversion?
viewtopic.php?f=4&t=7933#p70240

HTH!

[Ccaptain24]

Hi,

It has a five wire O2 sensor. My experience of driving compared to others description of lean burn at work convince me it is so. I shall have to get a meter and confirm it some time.

Em