Very poor fuel consumption corolla HB 2021 1.8. 33mpg. why. 120miles non stop with cruise on 110kmph

[ColinLimerick]

Hey, I just bought a 10month old corolla hybrid 1.8 HB from Toyota dealer. All their tests pass and looks like a great car. The dealer is 120 miles from home and on the way back the fuel consumption read 7.0l/100km and reduced over the 120 mile journey to only 6.7l/100km. I presumed this was an average of the previous owners tips but it isn't. What is going wrong please and what do I do?

[dee123456]

That's rather low but it will also depend on how you were driving. If you had your foot to the floor and driving at high speeds then this could be why it's so low. Most of my journeys are round town and this tank of fuel i'm getting 62.5mpg. On a long journey i would expect to get over 70mpg with my driving style.

[AndrueC]

That's not 33 mpg it's nearly 43 mpg (UK gallons). That doesn't sound too bad. What were the weather conditions? Was it flat or hilly? What are the tyre pressures?

The hybrid system can't work miracles. Moving over a tonne of metal at 70 mph requires energy and that means burning fuel. At motorway speeds the hybrid system just can't do a great deal to help the ICE. It doesn't have the power to meaningfully assist. I'd still expect over 50 mpg from a 1.8 HB (on the few occasions where I've gone that speed over that distance I do) but it wouldn't take much to drop it further.

There's also the possibility that the dash is over reporting (although it tends to under report for most of us).

[ColinLimerick]

2 hours ago, AndrueC said:

That's not 33 mpg it's nearly 43 mpg (UK gallons). That doesn't sound too bad. What were the weather conditions? Was it flat or hilly? What are the tyre pressures?

The hybrid system can't work miracles. Moving over a tonne of metal at 70 mph requires energy and that means burning fuel. At motorway speeds the hybrid system just can't do a great deal to help the ICE. It doesn't have the power to meaningfully assist. I'd still expect over 50 mpg from a 1.8 HB (on the few occasions where I've gone that speed over that distance I do) but it wouldn't take much to drop it further.

There's also the possibility that the dash is over reporting (although it tends to under report for most of us).

Thanks

i had the cruise control on the whole way.  Driving conditions were normal and not windy or raining.  I checked tyres and all read 33.  
Since I got the car the fuel consumption indicator has changed very little and no reads 6.7/100km.  We have 3 cars and 1 is a 1.8 17 year old vw petrol and it shows 5.6/100 now.  
 

 

aggghh

[Scout117]

I have the 2.0 litre did a round trip non stop of 340 miles dash was showing 61 MPG. I did reset the mpg meter before starting the journey so 33 for 1.8 seems low. Not sure how accurate the mpg shown by the car is though.

[dee123456]

Did you reset the MPG before the journey home? I always reset mine each time i fill my tank up.

[FROSTYBALLS]

10 minutes ago, Scout117 said:

so 33 for 1.8 seems low

Conversion to UK gallons gives 43mpg - OP used US gallons originally

[ColinLimerick]

7 minutes ago, FROSTYBALLS said:

Conversion to UK gallons gives 43mpg - OP used US gallons originally

I’m not sure about mpg but 6.7/100l is low.  

[RIbbotson]

1 hour ago, ColinLimerick said:

Thanks

i had the cruise control on the whole way.  Driving conditions were normal and not windy or raining.  I checked tyres and all read 33.  
Since I got the car the fuel consumption indicator has changed very little and no reads 6.7/100km.  We have 3 cars and 1 is a 1.8 17 year old vw petrol and it shows 5.6/100 now.  
 

 

aggghh

Tyre pressure seems a bit low at 33 this will lower the fuel economy. My Toyota garage always sets the pressures at 33 all round but on my drivers door frame at says 36 front and 35 rear. I readjust my tyres to this after every service and am averaging 60.1 mpg since last September.

[TonyHSD]

This fuel consumption is wrongly calculated or understood. This car to consume that much of a fuel needs to be overloaded and driven on step uphills at constant high speeds, otherwise in any other cases will be max 5.7ltr/100km. My suggestion is to re fill the tank , reset the trip computer, make a note of the mileage and refill again at the same pump after a week or two then check fuel consumption brim to brim from the  first click and compare to the car dashboard readings. Tyres pressures are crucial and needs to be checked on cold and set to the correct levels, front doors label. 👍

[AisinW]

2 hours ago, ColinLimerick said:

I’m not sure about mpg but 6.7/100l is low.  

It looks fine because it als match ADAC test at 130 km/h 7.2 L/100 Km on 2.0L Touring Sport.  If you drive consistently at 100km/h, you will get 4.5L/100 Km easily but above it, the MPG drops rapidly from higher drag coefficient of Corolla (0.3)  vs Auris 2 (0.28). 

https://assets.adac.de/image/upload/Autodatenbank/Autotest/AT5923_Toyota_Corolla_Touring_Sports_2_0_Hybrid_Club/Toyota_Corolla_Touring_Sports_2_0_Hybrid_Club.pdf

[ColinLimerick]

16 minutes ago, AisinW said:

It looks fine because it als match ADAC test at 130 km/h 7.2 L/100 Km on 2.0L Touring Sport.  If you drive consistently at 100km/h, you will get 4.5L/100 Km easily but above it, the MPG drops rapidly from higher drag coefficient of Corolla (0.3)  vs Auris 2 (0.28). 

https://assets.adac.de/image/upload/Autodatenbank/Autotest/AT5923_Toyota_Corolla_Touring_Sports_2_0_Hybrid_Club/Toyota_Corolla_Touring_Sports_2_0_Hybrid_Club.pdf

Im in the 1.8 HB model. 

Just noticed the tyre pressure symbol is lit up on the dash. Tyres are 33 all around. Could this be it?    perhaps a fault with tyre pressure monitor??

[AisinW]

The 1.8 Corolla is more efficient than Auris 2013 in city and below 100km/h.  Above 120km/h, the Auris is still more efficient because of better aerodynamics than Corolla.  Unfortunately, the looks of Corolla which is more modern does not come with better aerodynamics.  A kind of step back 5% less aerodynamics. 

Tire pressure effects the MPG especially if you have 5 passanger and less than 32 PSI cold.  Just follow what is in the door jam. I believe it is 32-37PSI depends on the number of people and load. 

[Cyker]

You don't live on the nurburgring or something do you??  

[Stopeter44]

As others have asked, are you usual trips on hilly roads ?

ACC will try very hard to maintain speed at will accelerate and, when necessary, brake hard. None of which helps get the best fuel consumption.

Also the difference between running at, say, 105 kph and 110 kph, in fuel consumption is noticeable. In my Yaris, the sweet spot is roughly 70-100kph, above 110kph you will really take a hit.

[ColinLimerick]

2 minutes ago, Stopeter44 said:

As others have asked, are you usual trips on hilly roads ?

ACC will try very hard to maintain speed at will accelerate and, when necessary, brake hard. None of which helps get the best fuel consumption.

Also the difference between running at, say, 105 kph and 110 kph, in fuel consumption is noticeable. In my Yaris, the sweet spot is roughly 70-100kph, above 110kph you will really take a hit.

I live in a very flat place in the centre of Ireland. all my local trips are on flat roads. I cycle and run - I know them to be flat. 

The tyre pressure light is permanently on even though the tyres are correct. Is this the issue?

[RIbbotson]

The tyre pressure light simply tells you that at least one tyre has dropped below pressure, this could even be the spare if you have one. The tyre pressure light has to be setup via the cars control panel after inflating all tyres to the correct pressure. I have never had to reset mine but it normally comes on if any tyre drops bellow 32psi.

Please confirm that your pressures are set as stated on the drivers door label. I am fairly certain it will be greater than the 33psi that you said yours are set to. 

[AisinW]

Tyre pressure light usually means TPMS are not registered if you had check the pressure is right.  You can re-initate al the TPMS once you are at correct pressure ~35 PSI.   The main benefit of Turbo engine and diesel is flat Torque curve from about 1500 rpm to 4000 rpm and often they are more efficient at higher  speed than small hybrid cars.  I doubt there is any issue in your car.  Just check again after 300km trips cruise at about 100km/h, you should get about 4.5-5L/100 Km.    The tire pressure light will be on when it is below 28 psi if I set it at 35 psi.   

[ColinLimerick]

3 minutes ago, RIbbotson said:

The tyre pressure light simply tells you that at least one tyre has dropped below pressure, this could even be the spare if you have one. The tyre pressure light has to be setup via the cars control panel after inflating all tyres to the correct pressure. I have never had to reset mine but it normally comes on if any tyre drops bellow 32psi.

Please confirm that your pressures are set as stated on the drivers door label. I am fairly certain it will be greater than the 33psi that you said yours are set to. 

the door jam says 33/31.  that's what its at now

[Mylesmck]

What did it show before you started your journey? I’ve just bought a saloon which seemed to show 4.6l/100km no matter how I drove the first few days. After I filled it I reset it and it varied wildly in the first few miles. Now it’s at 4.4, and I think it would have stayed lower (around 4.1) only the last few hundred kms have been on the motorway (not the hybrids fortè). I don’t know if you were watching the energy monitor as you drove, but I don’t think the electric end does much at motorway speeds so you’re essentially driving a 1.8 petrol…

[AndrueC]

22 minutes ago, Mylesmck said:

I don’t know if you were watching the energy monitor as you drove, but I don’t think the electric end does much at motorway speeds so you’re essentially driving a 1.8 petrol…

Albeit one that is operating on a simulated Atkinson cycle. Based on a comparison with my old Jazz I think in power (and possibly fuel consumption) terms it's equivalent to a 1.4l.

[TonyHSD]

1 hour ago, Cyker said:

You don't live on the nurburgring or something do you??  

I knew it 😂🏁

[TonyHSD]

36 minutes ago, Mylesmck said:

What did it show before you started your journey? I’ve just bought a saloon which seemed to show 4.6l/100km no matter how I drove the first few days. After I filled it I reset it and it varied wildly in the first few miles. Now it’s at 4.4, and I think it would have stayed lower (around 4.1) only the last few hundred kms have been on the motorway (not the hybrids fortè). I don’t know if you were watching the energy monitor as you drove, but I don’t think the electric end does much at motorway speeds so you’re essentially driving a 1.8 petrol…

Not exactly, the hybrids always will be more efficient than petrol only equivalent because even on high speeds they still work in combination with the electric motor and maintain lower rpm, similar to Diesel engines. In general with sensible driving the fuel consumption is very similar driving in town or motorway with some exceptions where if you want to be extra careful and drive on empty streets you can even beat the manufacturer figures 👌

[Mylesmck]

22 minutes ago, TonyHSD said:

Not exactly, the hybrids always will be more efficient than petrol only equivalent because even on high speeds they still work in combination with the electric motor and maintain lower rpm, similar to Diesel engines. In general with sensible driving the fuel consumption is very similar driving in town or motorway with some exceptions where if you want to be extra careful and drive on empty streets you can even beat the manufacturer figures 👌

……. Anyway, to the OP: I would reset the display reading and see what it settles at after a few more journeys. If still bad investigate further or return to dealer

[AisinW]

Yes, you are right, it is still more efficient than any comparable gasoline turbo engines. Diesel will win just because the internal energy of diesel fuel is 30% more and the compression ratio can be really high and can reach beyond 41% thermal efficiency.  Toyota still holds the record on most efficient gasoline engines at 41% thermal on 2.0 and 2.5L D4S. 

With Corolla Adaptive cruise control, you can follow semi trucks at 100 km/h at maximum adaptive distance and get 3.5L/100 km consistently in Motorway or Autobahn.