Tekstep

I recently picked up a Flint Mica Xa last Saturday and averaged 35.6 mpg for my 1st tank of gas. I think the gas mileage isn't bad for my 1st tank but I wanted to see if there was a way to lower the rpms at speed and ultimately increase gas mileage at the same time. I noticed the motor runs at 3500 rpms going 70 mph and 4000 rpms around 80 mph which is a little high for my liking. I would think that by lowering the rpms with different gearing could help increase gas mileage. To do this the final drive ratio would need to be changed as well as 5th. Even better yet would be an extra gear and a different final drive ratio.

Here’s what the stock gearbox ratios are set at.

1st 3.545
2nd 1.904
3rd 1.310
4th 0.969
5th 0.815

Final Drive 4.31

Gearbox:-
Tyre:- Michelin all patterns 195/60 x 15
--------------------------------------------------------------------------------------
Engine speeds in top gear:-
30 MPH = 1508 RPM 40 MPH = 2010 RPM 50 MPH = 2513 RPM
60 MPH = 3015 RPM 70 MPH = 3518 RPM 80 MPH = 4020 RPM
90 MPH = 4523 RPM 100 MPH = 5025 RPM

Here’s one option that I would like. (Change final drive to 3.65)

1st 3.545
2nd 1.904
3rd 1.310
4th 0.969
5th 0.815

Final Drive 3.65

Gearbox:-
Tyre:- Michelin all patterns 195/60 x 15
--------------------------------------------------------------------------------------
Engine speeds in top gear:-
30 MPH = 1277 RPM 40 MPH = 1702 RPM 50 MPH = 2128 RPM
60 MPH = 2553 RPM 70 MPH = 2979 RPM 80 MPH = 3405 RPM
90 MPH = 3830 RPM 100 MPH = 4256 RPM

I'm not sure if this would even work. (Add a 0.611 6th gear for cruising)

1st 3.545
2nd 1.904
3rd 1.310
4th 0.969
5th 0.815
6th 0.611

Final Drive 4.31

Gearbox:-
Tyre:- Michelin all patterns 195/60 x 15
--------------------------------------------------------------------------------------
Engine speeds in top gear:-
30 MPH = 1130 RPM 40 MPH = 1507 RPM 50 MPH = 1884 RPM
60 MPH = 2260 RPM 70 MPH = 2637 RPM 80 MPH = 3014 RPM
90 MPH = 3391 RPM 100 MPH = 3767 RPM

The calculator I used to perform the gear setups can be found here - > http://www.quaifeamerica.com/downloads/QSpeedCalc.exe

I understand that changing the final drive will also affect acceleration which is already bad in this car.

Does anyone know if the final drive ratio is different for a Corolla, Echo, Yaris or Prius that might possibly work in the Xa's gearbox?

Are there any tuners that have a gear set out for the Xa?

RTon20s

There has been quite a bit of discussion about this. I think dgHotLava has switched his final drive over, and is very happy with it.

There has also been lots of discussion about just swapping 5th gear with an Echo. As far as I know, nobody has done this yet though. Some people say it should work, but I don't know.

Try and search this forum and I am sure you will turn up a couple of other posts to look at.