Bad Fuel Avg (7~8km/L in city) Mazda Carol 2009 660cc

[pwuser154125129441]

AOA,
1. I have bought Mazda Carol GII 2009 and fuel average is 8 km/L in city with AC . I also own a city 2008 manual and it gives alot better average. Details are as follow:
A. Engine oil: ZIC 10W40
B. Spark plugs: Iridium
C. Catalytic convertor: Not installed (surprise after purchase)
D. No checklight is observed in ODO meter, no error code in scanner. I am using SZViewer to see data.

1. I have drive it to Murree and engine is good. I wonder what could be the issue, Such bad fuel average could be due to absense of catalytic converter?

2. There must be a way to diagnose issue with the help of scanner and data analysis. I think bad Fuel avg is reflected in fuel trims, I have a scanner but i am not able to understand or correlate.

3. Can anybody help me understanding the fuel trims? Or may see the trims data and guide accordingly. I know that catalytic increases fuel efficiency but i wonder how much difference will it make? May be there is some other issue as well.
4. I will be happy if someone can guide me over the phone. My contact is 03225561299
5. What is the avg of this model in city. Can anybody using this model share his experience with the fuel avg?

Thank you

[horticulturalist]

Whats the recommended grade oil for this model by the company?

[pwuser154125129441]

[horticulturalist]

So you are using 10w-40 which is one of the culprit of bad fuel average. Change it to 5w-30 of a popular brand from genuine shop or daraz. Do cleaning of plugs, fuel filter, throttle body, test injectors, change AF. The fuel avg will get better I.A upto 15kmpl.

[asadgitl]

Hi Asghar, sure I’ll guide you the best that I could do without physically inspection. Keep in mind average and performance factors also includes out of the engine box. Example wheal alignment , recommended tyre pressures, make sure all of wheels are free to rotate in neutral position, Engine matters : Note that even you have no engine check light isn’t mean every thing is perfect. communication in between ecu with sensors input output most important factor for performance, engine check light …

Check my post definitely it will help out

[helper_learner]

You are in Rawalpindi, Right?

Visit @dani_kk or @rajaatta

They will help you in this regard... they are in Islamabad...

BTW the problem is bad oil grade... missing Catalyst converter....

And by the things you have mentioned shows that car is messed up and most likely it is running cold without thermostat valve and auto fan and also on water instead of coolant...

And maybe wiring is also messed up.... you need to get your car properly checked...

[dani_kk]

You need to visit for a inspection. A compression test would help. Along with complete car obd2 scan.
Szviewer is basic app. Incase of any problems, the professional scanners help.

[pwuser154125129441]

Thank you for the reference.
Fan is auto, thermostat valve is also working.
Found a throttle leak in a pipe which connects sound box to throttle body, thanks to @asadgitl and @ahmad for their guidance.
PCV valve is also suspected to be faulty. Will check that in the afternoon IA

[pwuser154125129441]

Have done few fixes. Will bring it to you IA if issues dont get resolved.
Thank you

[asadgitl]

Good luck bro:+1: