Worst fuel average : Urgent advice required

[pwuser150329972847]

Good afternoon Pak Wheelers,

I have a Toyota Vitz 2006 model, with 1KRFE (1000 CC) Engine, Vibration issue was resolved by changing all engine & gear mounts but there is excessive fuel consumption.

My daily commute is Home to Office & back to home, occasional outings with family. Past 4,5 fuel filling results are disastrous, I am getting fuel average of just 7-8 KM / LTR. (300-320 KM on full tank refill) with A/C of course.

Tyres size is : 185/70/ R14 with after market RIMS of good quality.

Tuning is done, Engine oil changed, Filters changed, plug checked, all throttle body cleaned & rest of important tasks were taken care of,

I have also used High-octane of Total Parco, still no difference.

Can anybody confirm what can be the cause of this pathetic fuel average, normally we purchase small cars for a better economical fuel average but this is causing me lot of distress.

Thanks

[the_mira_guy_08]

Tire size is too big i've noticed. People get better mileage on the 1300cc variants more than 1000cc variants on some occasions. A vitz with the family in the back with ac on oversized tires won't get you good mileage on a 1 ltr 3 cyl.

[pwuser150329972847]

What could be ideal tyre size for this vehicle, I understand that 1300 CC would give a better reading, but I have noticed people getting good average from this 1KR engine as well, 7-8KM / LTR is really really low.

So can you recommend any ideal tyre size?

[pwuser166331039855]

So can you recommend any ideal tyre size?

open the driver door and there will be sticker on the door jams which has information about the color trim of car, wheel sizes & recommended pressure. Plz check and post the photo here.

different Vitz variants came with different rim sizes from 13" to 15"

[pwuser166331039855]

Tuning is done, Engine oil changed, Filters changed, plug checked, all throttle body cleaned & rest of important tasks were taken care of,

how about sensors like O2, MAF, etc.

[pwuser150329972847]

We did clean all these during last tuning 2 weeks ago, they said everything is fine.
Total tuning of car was done.

[pwuser150329972847]

Hi, thanks for your reply.

Yes I found this piece of information

[pwuser166331039855]

Tyres size is : 185/70/ R14 with after market RIMS of good quality.

The recommended size is 165/70/R14
you are using 185/70/R14

this is for sure there will be its impact on the fuel consumption as well as on the speedometer too.

Now you have to make sure about the o2, maf and other sensors which are mounted in the engine bay and play imported role in fuel economy.

[xzap042]

If you 'serviced' the O2 and MAF sensor with carb cleaner or similar item, then they're shot

[Xulfiqar]

There is your culprit!

[dayrider]

Tuning is done, Engine oil changed, Filters changed, plug checked, all throttle body cleaned & rest of important tasks were taken care of,

Change tour mechanic, what city are you in? 1kr vitz does 14 to 16 easily with ac

[Xulfiqar]

What were the total fuel trims learned over time? Or did mechanic delete all data, cleaned everything and demanded money?

[pwuser150329972847]

I am in Lahore, I think it was a normal tuning, CAT cleaned, spark plugs checked and cleaned, brake service done, engine/oil filter changed, throttle body cleaned.

I think most of the comments are related to tyre size as well, so I think I can try changing tyres and see how it goes.

[pwuser150329972847]

I think he didn’t do any thing like this, he cleared a DTC maybe, and that too of Brake switch.

Other than that, I don’t think he was capable enough to play with any readings of programming.

[Xulfiqar]

Please dont hire morons to repair your car!

[dayrider]

think most of the comments are related to tyre size as well, so I think I can try changing tyres and see how it goe

No. Tires wont make squat of a difference. Take your car to johar town. Project 11
@syncview

[pwuser150329972847]

Sure, will visit them today

[ahmar.mirza]

As far as i remember i am using same tyre size as yours in my vitz 2012. The average I am getting in Lahore with AC is between 12.5-13 and my commute is very less so average always increase over the weekends.

Last time i got throttle body, spark plugs cleaned and the average fell to 9 and i was worried. It was done by same mechanic and same things done but never had that issue before. I went to him and he said just drive and it will improve which somehow happened. Really not sure what happened at that time but it was back to 12.5-13 in a week's time.

For CAT cleaning i always go to motor clean where they dont open the cat and clean it with some machine. What I know/heard getting cat cleaned by these local mechanics, they always make mess with it.

[Xulfiqar]

You are pretty good with wasting money!

You dont need throttle, maf, injector or cat cleaning, just drive the car, it will run perfectly fine and it self cleans and self adjusts.

Motorclean is a huge scam, they only prove their work with “sir pickup dekhein”

They cannot and will not ever show you the cat converter pre and post pressure reading or even its oxygen holding capacity.

The reason your “average” fell was because your mechanic deleted the learned fuel load adjustment trims (your car learns and self adjusts according to engine condition and driving style)

Please stop wasting money on such scams, cars since 30 years have not needed the monthly ziyaratt at mechanic

[pwuser150329972847]

Hi good evening,

You are right, I have lived in UAE for past 5 years, there is no concept of ‘tuning’ there.

Should I now keep driving car & expect it to better automatically, I have changed tyres however, previously it was a chinese brand with 185/70/R14, I have switched to Dunlop 165-70-R14.

So hopefully we can expect some improvement.

Thanks for your support though.