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Ulev 5spd vs Sulev CVT.

2410 Views 9 Replies 6 Participants Last post by  BLUEBUG
Ok this is maybe a stupid question but I am going for it:

Why is there an emissions level difference between a CVT and a 5 spd ?
Does the CVT has leanburn or not ?
What is the exact difference between the 2 engines without
the cvt or 5 spd gearboxes. I don't have a clue.
I know that leanburn exhaust gasses are more "dirty" compared to non-leanburners due to the fact that the combustion is not optimal compared to non leanburners.
In this part I see that the engine compression ratios are 10.8 to 1 (5spd) and 10.3 to 1 (CVT). I tought that for a leanburn engine, the ratio is about 22 to 1.
So as I have to say: What is it ?
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Your right on that, the CVT is geared more towards emissions, the 5 speed towards mileage. I think the difference in the compression ratio is in the head. No lean burn on the US CVT that's for sure; however, if you look on the Japanese Honda site (using a translating program) they show both of theirs as 10.8:1 with both transmissions so in theory they have lean burn CVT's, and *maybe* if someone imported a Japanese ECM you could have a lean burn CVT here. I've looked at a couple CVT Insight's and they still have the NOX catylst there, which is primarily to hold back the NOX emissions while in lean burn. Not sure what you guys get in the europe market.

Still, those who have had emissions tests all I can remember hearing about blew in sub SULEV levels.
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