JDM cars get higher MPG with taller trannies

[GasSavers_Ryland]

I was just looking at this site and noticed that the JDM cars got better mileage, and was slightly confused, then I looked at the final drive, cars like the Honda Fit 1.5L sold in the US get 38mpg with a final drive of 4.562, the Japanise sold Fit 1.5L gets 45mpg with a final drive of 5.777, I noticed the same thing with the JDM honda insight that is suposed to get 80+mpg.
I realize that their valve timing, and ignition timing is most likely slightly differnt as well, but from what I could tell their toruqe, and hp ratings are about the same, along with tire size.

[landspeed]

Are you comparing the same types of MPG?

[omgwtfbyobbq]

It also has a CVT while ours has a normal automatic transmission.

[Matt Timion]

Argh... and the Honda Fit 1.3l gets over 56MPG. Now I want that engine/ECU/transmission again.

[GasSavers_Ryland]

I think I might have made a mistake... I happened to come acrose that page very late at night and wasn't thinking clearly, the JDM cars have shorter final drives, not taller, I had my gear ratio figuring fliped around.
as for my mpg gallons, they are based off Km per liter, then ran "Km per liter to mpg" thru google to get the figures that I was going off, I rather suspect that their stated mpg numbers are at 55mph, or some other lower speed.

I do still find it fasinating that their numbers for all of the JDM cars are higher then anything you can find in the US, nearly all of them are at least 40mpg or more, some in the 60's, I'll keep looking and see if I can find any accurite information that is useful.

[Sludgy]

No company selling cars in America puts its highest FE engine / tranny combinations on the road. The 1.5 L Honda Fit has obviously met the NHTSA, DEP and DOT regulations. So why can't Honda gear the Fit for FE and / or use the smaller, high-FE motors in its home market parts bins? It's a conspiracy, I say.

Not that I want a Honda. I want a full size 4x4 truck.

Chevy doesn't even offer a V-6 in its 2007 GMT900 pickup. The smallest engine offering is their 4.8 V8. I'm in the market for a truck to replace my F350 P.O.S., but I won't part with any of my cash until somebody makes a 25 MPG 4x4 pickup truck.

[Spule 4]

Also remember Japanese driving rules and habits (do they factor in a ton of idle time?).....and a top speed of 100kph, with "a spot of onboard bother" (a buzzer that gains in volume as you get over speed) if you exceed it. Apparently, with current electronic and celluar technology, there is talk now of linking the buzzer to speed limits, you enter a 40kph zone at 45.......BUZZZZZZ.....