[mattcand]

Hi all, just purchased a used CVT. I was wondering if anybody has created any kind of mod to allow a CVT to run in lean burn mode. I would guess it is just a software thing but what do I know. The CVT might not even have the fancy exhaust sensor that the Manual Trans has.

Matt

 

[Rick]

Ok this is iffy at best with our forum rules about emissions modifications, but I have a theory. If you look at the Japanese Honda web site for information on the Insight it appears that their Insight's with CVT's are in fact lean burn. The CVT Insight's do indeed have the same exhaust system and both catylitic converters and all 3 O2 sensors (for 02's and newer... 2 O2 sensors for older models). So it may be as easy as getting a Japanese ECU and swapping it out, though there is absolutely no guarantee this would work at all.

The other consideration is something in the engine is different. The lean burning 5 speed has 10.8:1 compression where the CVT gets 10.3:1 compression. I'm not sure what the difference is, but on the Japanese site it indicates both transmissions there get 10.8:1 compression.

Of course if you had the CVT lean burn it would effectively lower it to a ULEV from a SULEV emissions rating, which is probably not legal.

 

[b1shmu63]

Honda has research lean burn engines for decades. I suspect that it is much more involved than a software change. Any engine can be adjusted lean. Doing so dramatically raises NO2, will cause you to fail emissions testing, void your warranty, castrate your cars performance, and may damage your engine. Therefore, (as Rick mentioned), we cannot discuss this here.

However, there are many tips that apply to CVT engines as well as 5 speeds. The biggest gains are achieved through practice and technique as well as simple things like extra pressure in the tires, synthetic oil etc.... This was demonstrated by hypermillers who went off the scale at Hybridfest achieving double EPA in both Prii and Insights. (You may wish to contact one of the winners directly.)

Congratulations on your purchase and welcome to the forum.