Nissan mods the Versa: fuel economy up by 1 MPG
 

Via ABG...

http://www.blogcdn.com/www.autoblogg...a_hatch_11.jpg

Nissan has joined the ranks of automakers like GM (with its XFE models) and others who are returning to existing models to mod them and squeeze out a bit better fuel economy.

The Versa's CVT has been tweaked (software) for one extra MPG.

It's one of 3 transmissions offered:

CVT: 27/33
M-6: 26/31
A-4: 24/32

Compare to:

Toyota Yaris
M-5: 29/36
A-4: 29/35

Honda Fit:
M-5: 28/35
A-5: 27/33

Chev Aveo:
M-5: 27/34
A-4: 25/34

Hyundai Accent:
M-5: 27/33
A-4: 26/35

No one offers a tall top gear. It's ridiculous. I know we've all been over this repeatedly, but most people with enough sense to drive a manual transmission also have enough sense to downshift to pass. I want my engine happily lumping along at 2k on the interstate, not 3.5k.

Why is that so much to ask?

Ditto.

We could easily see a 5-10% increase in highway FE with a simple gearing change.

My biggest gripe w/ CVT is that as soon as you ease up on the gas pedal, it downshifts and feels like you're riding the brake.

I have a bad feeling that the opposite may be true: call me a pessimist, but I'd bet that most North Americans who drive stick don't know enough to downshift to pass or get up a steep enough highway (top gear) grade without lugging.

For this to work, I think the extra tall top gear needs to be an option, not standard equipment. And that raises manufacturing/marketing costs, making it even less likely to happen...

Is there any precedent for a nerd gear option?

That might not actually be true... The automatic is so prevalent these days in the U.S. that the manual is typically coveted by those who can actually use them. There are still exceptions, however.

Can I get that option? :D

Assuming a dumb operator, what would probably be best is a CVT with selectable programming. Just put a fuel economy button on the dash aggressively switching the programming of the CVT toward fuel economy. I guess by now the general public kinda know the basics on driving for fuel economy (at least the kind of person that would buy a Versa). So if they press the fuel economy button I guess they would assume and accept the car behaving differently than with the regular "performance" setup.

well, if they made an extra gear, say for FE, they could just put on the visor to only use it on the highway, at steady speeds and flatland. I mean they still print airbag info on them.
or like tasdrouille said, a button for FE. it could work it automatics as well, keep the TC locked, remap the timing and fuel, only for highway use though. "Manufacture not responsible for your own stupidity" could be printed on the sun visor for that

I think it has to do with the fact that some cars don't have enough torque to get that gear any lower. On an automatic it can be lower but if you were to put such gearing on a manual it wouldn't necessarily increase your mpg. My civic barely makes over hills on the freeway in 5th gear. I drop about a good couple mph. In America everybody wants to have power, doesn't matter what gear they are in. Everybody has been complaining about gas mileage but have you noticed the displacement of engines go up every time they come out with a new model? Hello!

That is what 5th gear is supposed to be, overdrive.



A taller final gear ratio will most certainly increase mileage. If you look at almost any BSFC map you will see this. Many newer vehicles gear their automatic transmissions drastically lower than their manuals. This helps keep their mileage up when traveling on the highway. My guess is they don't do it on manuals because it may cause the operator to have to manually shift on hills like you mention.

IMO loose a few mph on the hill and get better mileage. I wish we had that choice.