(Note: decided to move the Metro related babble into this new thread, rather than continue to hijack Dan's Project KBA, KMA thread.)

Dan wrote:
Neither did I.

I haven't seen any information about lean burn at teamswift or in my factory service manual. I think the article you quoted is wrong there.

__________________
FF
ForkenSwift cheap electric car conversion- Geo Metro fuel economy mpg modifications

Only the Metro XFi had lean burn.

Are you sure about this?

I've seen several comparisons of the XFi drivetrain design vs. regular 3-cyl Metros, and have never seen lean-burn on the list. I think if it did have lean-burn, its numbers would be even higher than they are.

Would lean-burn require a 5-wire o2 sensor, for example? Both the XFi and non-XFi share the identical part there, and it's a 1-wire affair (for a '94 Metro, according to the rockauto.com catalogue).

I've raised the question at teamswift - maybe someone can answer definitively.

---

PS - anxiously watching this thread to hear about Dan's trip...

__________________
FF
ForkenSwift cheap electric car conversion- Geo Metro fuel economy mpg modifications

I don't know. I remember reading that the XFis were lean burn when I first started looking for a Metro (I didn't realize they were US-only at the time). As far as I know, the lean-burn was entirely controlled by the ECU (which is different for the XFis compared to the standard Metros).

I think the ECU may have looked for the lean-burn signal from the O2 sensor rather than lambda, but I don't know.

I actually remember reading that the NOx emissions were higher on the XFi due to the lean burn, but I'll have to find my source again.

Heard back from a teamswift member, who intelligently pointed out that the sentence in the linked article doesn't explicitly say that the Metro has lean burn. Read it again...

Teamswift guy's interpretation:

So it may just be a case of poor sentence construction leading to an incorrect implication. E.G...

Bank robbers often drive getaway cars, and Dan is driving his new VX from Chicago today.

__________________
FF
ForkenSwift cheap electric car conversion- Geo Metro fuel economy mpg modifications

I knew there was something odd about dan...

Anyway, why doesn't someone just hook a DMM up to their car and go for a little ride?

Yeah, all that money to spend on cars must be coming from somewhere....

I think I've already done the DMM lean burn test equivalent for my car when I did the speed vs. mpg chart. If there were a lean burn mode, I would think it would show up differently than the essentially smooth line I got. From the reading I've done of Insight drivers, the slip in & out of lean burn mode is blatantly obvious on the instant fuel consumption display.

However, if it's only an XFi feature, I can't test that. But... the owner of the XFi who pointed out the sentence structure issue was also unable to find any reference to lean burn in his service manual.

__________________
FF
ForkenSwift cheap electric car conversion- Geo Metro fuel economy mpg modifications

I have no clue where I got the idea it was. I actually wrote it in my log way back in September/October. Maybe I found a reference to NOx emissions and assumed the XFi was lean burn...

I'll just say it was due to my brain-cloud.