Bad O2/Lambda sensor or bad MPG values?

[asrhael]

Hello:

This is the first time that I write in this forum, and I do now, because i love my used Auris, but I think that "he" (yeah, it have a name...his name is "bolido") have a issue related to the fuel consumption. My car have the next specs:

• Year: 2013
• Model: Auris (ZRE181L-DHFDP)
• Fuel: Petrol
• Engine displacement: 1600cc
• Mileage: 60,000km (37,300 miles)

After one year of use, and 10,000km traveled, the MPG indicator show me a worrying value of 25 (approximately 10.6 km/l). In this situation, reading about this car, honestjohn website tell me that a value near of MPG=39 would be fine (16.5 km/l), so, I ask a friend for help, and he told me that I "never would trust on the MPG ECU values"...for this reason i decide to register my fuel charges, mileage (in km) and volume of charged fuel (litre), the results are the next ones:

• mid of march: 151 km traveled, 14.8 litre charged: performance of 24 MPG, or 10.2 km/l
• end of march: 295 km traveled, 28.8 litre charged: same performance of 24 MPG, or 10.2 km/l

In this scenario, and despair, I read a lot about the causes of that issue, concluding that my Denso DOX-0503 (89467-12030) would be the problem, so I extracted of my engine (the upstream one, before the catalytic converter), putting immersed on a chemical cleaning solution for three days, then drying and re-connected to the engine.

After that, and in a shor travel of 40km (25 miles), the engine performance indictador show me a value of 31 MPG...that is more than my accumulated value of 24, but less than the value that Honestjohn told me (39).

Is my O2 sensor damaged?, or my reference MPG value is the problem?

Please, help me with yours MPG values for a 1.6 petrol engine and help me with this issue.

Thanks a lot!

 

Best regards,

Francisco

[FROSTYBALLS]

Presume the conversion into gallons is for US gallons rather than Imperial gallons (the measure the UK and the Honest John website uses is Imperial gallons).

1). 151km equates to 93.62 miles. 14.8 litres equates to 3.909 US gallons or  3.255 Imperial gallons.

Consumption works out to 23.94 mpg (US gallons) or 28.76 mpg (Imperial gallons).

2). 295km equates to 182.9 miles. 28.8 litres equates to 7.608 US gallons or 6.335 Imperial gallons. 

Consumption works out to 24.04 mpg (US gallons) or 28.87 Imperial gallons.

Can you confirm what type of driving environment the above mileage represents - eg city, freeway, route, mixture of both or all three, heavy stop start traffic, light traffic, etc.

Have you been using 93 RON, 95 RON or 97 RON fuel? Does the fuel contain ethanol, and if so what percentage - 5% (E5) or 10% (E10)?

[furtula]

You are doing quite short distances per month, are those mostly short trips to store?  Combine that with colder weather, and a bit heavier foot, and you can get 10L per 100km.

Have you thought about resetting the ECU, by disconnecting the Battery for 10 minutes? 

As above, i think you got the values mixed up by converting to UK gallons.

 

[asrhael]

11 hours ago, asrhael said:

Hello:

This is the first time that I write in this forum, and I do now, because i love my used Auris, but I think that "he" (yeah, it have a name...his name is "bolido") have a issue related to the fuel consumption. My car have the next specs:

• Year: 2013
• Model: Auris (ZRE181L-DHFDP)
• Fuel: Petrol
• Engine displacement: 1600cc
• Mileage: 60,000km (37,300 miles)

After one year of use, and 10,000km traveled, the MPG indicator show me a worrying value of 30/25 (UK/USA, approximately 10.6 km/l). In this situation, reading about this car, honestjohn website tell me that a value near of MPG=39 would be fine (13.8 km/l), so, I ask a friend for help, and he told me that I "never would trust on the MPG ECU values"...for this reason i decide to register my fuel charges, mileage (in km) and volume of charged fuel (litre), the results are the next ones:

• mid of march: 151 km traveled, 14.8 litre charged: performance of 29/24 MPG (UK/USA), or 10.2 km/l
• end of march: 295 km traveled, 28.8 litre charged: same performance of 29/24 MPG (UK/USA), or 10.2 km/l

In this scenario, and despair, I read a lot about the causes of that issue, concluding that my Denso DOX-0503 (89467-12030) would be the problem, so I extracted of my engine (the upstream one, before the catalytic converter), putting immersed on a chemical cleaning solution for three days, then drying and re-connected to the engine.

After that, and in a shor travel of 40km (25 miles), the engine performance indictador show me a value of 38/31 MPG (UK/USA)...that is more than my accumulated value of 29/24, but less than the value that Honestjohn told me (39).

First of all, thank you guys for your quick check and comments; thank you FROSTYBALLS and furtula 🙂

I have quoted my post, and then correct and mark all MPG values...all my previous convertions to gallons avoid the differences between the UK and USA ones, and performing the correction, my performance appear to be within the acceptable range.

And is true, Im doing short distances daily, and per month, and mostly of them are in city, other ones (20%) are in highway at high speed (120km/h).

Good day guys!

[furtula]

If you take into account the cold months, lot of short trips, where car might not even warm up properly, your consumption is not that unusual, especially if you might have a heavy foot.

A bit higher yes, but not unusual.

You can't really expect awesome mileage in that conditions anyway.

Just for some comparison,  in same conditions, my 1.6 would show around 9.2L, and i'm really gentle with it until warmed up.

Have you tried resetting the average consumption, to exclude a lot of short trips you did earlier?

 

 

[asrhael]

1 hour ago, furtula said:

If you take into account the cold months, lot of short trips, where car might not even warm up properly, your consumption is not that unusual, especially if you might have a heavy foot.

A bit higher yes, but not unusual.

You can't really expect awesome mileage in that conditions anyway.

Just for some comparison,  in same conditions, my 1.6 would show around 9.2L, and i'm really gentle with it until warmed up.

Have you tried resetting the average consumption, to exclude a lot of short trips you did earlier?

Hello furtula,

In my last "short travel" of 40km, I decided to resetting the average consumption display (by long pressing the button on the display). In that short travel, using highway, the performance was 38/31 MPG (UK/USA) -approximately 7.5L/100km-.

it's true too that I don't warm up the motor before move in forward, and in the highway (in straight route) I go to 120-140 km/h...
 

[furtula]

That's the normal consumption for your engine, these are a bit rough numbers, but around 130kmh it will use 8L, at 120 around 7.2L, the ideal cruising speed is 100kmh with consumption at 6L.

When the car is cold, it uses a very rich mixture, meaning more fuel than usual, in order to heat up faster, that's why short trips in winter months give such bad mileage.

It should be better now in summer months.

[bonjo]

My car is a RAV4 2003 petrol so my comment is not specific to your model but may be of interest. I have had both the O2 sensore (upstream of the CAT) replaced (40k & 65k)

First, if either the O2 or Lambda sensor had gone fauly, you would get the orange check light.

If you run a diagnostics on the ECU, it will tell you if there is a fault with any of the sensors.

As you know many many factors affect the MPG; I understant ethanol in fuel makes it worse. So E10 should reduce your MPG more.

The octane rating (RON or ROM) would not should not affect it unless you go below the minimun rating but high octane fuel have additives that can help wil engine cleaning & improve the MPG. This is often misunderstood and people think the higher octance is the reason.

As other's have mentioned in winter months your MPG is worse (about 10% in my case). So a good quality synthetic oil is a must. I use 0w40 in mine since new and noticed an MPG improvement of about 10% over the original toyota oil.

Dragging/ sticking brakes also seriously afftect the MPG (15% in my case) and are difficult to notice by many people.