Question About Holden sidi v/s American sidi

[redonetoo]

I was looking at the tune for a Commodore 3.0 liter sidi v/s the Tune for my Terrain. Why wouldn't this tune work in my Terrain? Does Australia run less stringent emmissions than USA? How are they getting better fuel mileage than we are?

[ScarabEpic22]

No, you cant simply flash whatever OS you want into you ECM and expect everything to be better.

You can take parts of the tune (VVE and/or spark tables and/or VVT tables) and use those, but dont run anything but the factory ECM and TCM OS unless you have a really good reason. A swap is the most common for using different OSs.

[redonetoo]

What I was going to do was copy and paste from one cal to the other. For some reason in the PID s it won't read afr. I am not sure if it isn't supported or not. And even if I could I don't see where I could adjust anything to change anything. I can see where you can adjust timing of spark, cam phasing, and injection timing. But I see nothing in relation to fueling. I know I am new to this so all help is appreciated.

[Taz]

Hello Redonetoo,

A Terrain and a Commodore is not really an "apples to apples" comparison. The Commodore is lighter and more aerodynamic. With the exact same engine and tune as the Terrain, the Commodore should achieve better fuel economy. Also remember that US and Imperial gallons are not the same - using litres of fuel regarding international comparisons is helpful.


Regards,
Taz

[redonetoo]

When I purchased this vehicle new it never had any off the line performance. I carried it to 4 different dealers all saying there is nothing wrong. After 6 months of listining to my wife fuss about this wimpy car I pulled it in the back yard pulled the transmission out and found a faulty converter. I replaced the converter and while I had the transmission out I changed the final drive from 2.77 to 3.39 like in the srx. I flashed the TCM to an srx file. Do I need to flash the ECM to a SRX file to match. The SRX supposedly gets better mileage than the Terrain. But all that I do all I can get is 20 mpgs max

[Taz]

The Terrain and the SRX have a similar curb weight (when configured similarly) and have similar fuel consumption ratings. If memory serves, they are rated (AWD models) around 17 MPG city and 24 MPG highway (which was probably measured at 50 MPH on a chassis dyno, or similar device). Fuel economy in the 20 MPG range from either is what I would expect in "real world" driving - especially higher highway speeds (they are not aerodynamic, and "push" a lot of air).

Both vehicles are comfortable, spacious, and capable. Neither will ever be exceptionally fuel efficient. The enjoyment of either comes with a fuel cost.

Also the gear change you described above (2.77 to 3.39 gears) would have slightly increased fuel consumption, if the wheel and tire size remained the same.


Regards,
Taz

[redonetoo]

The Terrain is 2wd and the srx is 2wd. All SRX come with 3.39. The only 3.39 in Terrain is awd. If you can get 18mpg from a V8 why put a V6 in and get 20 makes no sense to me.

[Taz]

All good "points to ponder" - prior to making a purchase. If fuel economy was an important concern, and an SUV / CUV was the type of vehicle you wanted, then a 4 cylinder Equinox may have been a better choice. These had "segment leading" fuel economy ratings when first released.


Regards,
Taz