Corolla Touring Excel MPG Issue

[Carlosfandango]

Hi, I bought a new 2 litre Corolla Touring Excel in August and mpg consistently hovered around the 50mpg mark for the first few months then for no apparent reason dropped to less than 40 (around 36mpg at one point). It's now sticking around the 41.5 mark. I live in London and do a lot of city driving on Eco mode but I also drive on motorways reasonably regularly, including a trip to Utrecht where it gave 50mpg all the way there and back. I'm puzzled as to the sudden drop in mpg as I haven't changed my driving style or changed driving modes. The issue began before the cold weather but I was actually getting higher mpg with the aircon in August than I am now! 

 

Also, it often idles at 1500rpm even when the engine is warm - this is the first hybrid I've owned so I don't know if this is normal (charging batteries etc)

 

I asked the dealership about it and they were fairly disinterested but acknowledged that it was odd. Can I ask what mpg other Corolla drivers are getting and if anybody has experienced a similar issue?

 

Thanks in advance for any help!

[Mojo1010]

It's not apparently no reason, the weather is now cold, that's the reason. 

In my smaller MK3 Yaris, can get mid 70s on a run sometimes. In the winter 50s, short journey are below 50s. 

[Carlosfandango]

Issue started before the cold weather.

[Mojo1010]

You have nothing to worry about, that's how hybrids are. Have the car for a few years, then u will understand seasonal changes. It's the same for all engines really. 

 

[Parts-King]

In my experience of Hybrid driving (20 years plus) there are only two usual issues with MPG

• Cold weather
• Pilot error- heavy right foot 

 

[Carlosfandango]

Would either of those account for the car idling at 1500rpm though?

This is my first hybrid so how they function in cold weather is a new world to me but as mentioned in my original post, the issue began before the cold weather. I've been driving for 30 years and I know how to drive a car economically which is why this is a bit baffling!

[Sooty]

The cooler weather and then the really cold weather will affect the MPG quite a bit.

Also if you have started using the E10 fuel, that will affect the MPG as well.

I know about the E10 as my MPG had dropped by about 7 or 8 when I tried that c**p.

Went back to E5 and MPG restored itself.

[TonyHSD]

Agreed with all comments. The first reason here is the cold weather, much colder than before. The issue with mpg started before the cold weather, actually any temperature drop affect car fuel consumption, so basically from September through October and now the fuel consumption will be in one direction, up, more fuel less mpg. 
Second factor is indeed the fuel, E10 regular 95 is not efficient durian winter, best to be avoided and fill up with E5 99, there will be immediate consumption change 3-5mpg. 
Third factor here I can see is the driving needs (style). The 2.0 hybrid is not as efficient as 1.8 hybrid and especially when driven at low town speeds. On long journeys in ideal conditions and driven sensible can come close to 1.8 but in any other circumstances it will be 5-10 mpg less. 
Another reason for sudden mpg change linked to the cold weather is the tyre pressures, they drop significantly even overnight if the car been left without use and temperature varies by 8C° or more. Best to check and adjust accordingly, keep them at max recommended by the door label measured on cold before driving off. 
We had discussed many times now about cold weather and tyre pressures and fuel types and how all of that affects Toyota hybrids. 
Short town drives are the worst for any car different from full Battery electric or hydrogen fuel cell electric car. These two are the most efficient when used in towns. 
The car will idle at 1500 and more to recharge the Battery and to provide heat to the cabin and keep engine warmed up. I believe there is nothing to worry about, just check your tyres, hvac settings and you can try e5 petrol. Tesco btw sells at good price and it’s a good one 👍

[Mojo1010]

August and October temperature are quite a gap, it's much cooler in Oct, this affect mpg, doesn't need to be cold like it is now. 

As said above, 1500rpm is quite normal to recharge hybrid Battery and heat cabin, it's not like a normal engine where once warm, idles around 7-800 rpm. 

And yes 2.0 touring isn't very fuel efficient either. You have nothing to worry about, we have owned hybrid cars for a good number of years, we know what we're talking about this mpg thing. To achieve a bit higher mpg, need to turn off all heater in the cabin - no heated seats/steering wheel. Have to be a gangster like @Cyker

[Geoff W]

Y

28 minutes ago, Mojo1010 said:

August and October temperature are quite a gap, it's much cooler in Oct, this affect mpg, doesn't need to be cold like it is now. 

As said above, 1500rpm is quite normal to recharge hybrid battery and heat cabin, it's not like a normal engine where once warm, idles around 7-800 rpm. 

And yes 2.0 touring isn't very fuel efficient either. You have nothing to worry about, we have owned hybrid cars for a good number of years, we know what we're talking about this mpg thing. To achieve a bit higher mpg, need to turn off all heater in the cabin - no heated seats/steering wheel. Have to be a gangster like @Cyker

"1500 rpm is quite normal"

YES - The whole point is that a hybrid doesn't run it's engine at all unless there is a need. And if it needs to generate heat or top up the Battery it will run at the most efficient speed in order to achieve this and that won't be a slow tick over.

[Cyker]

3 hours ago, Mojo1010 said:

August and October temperature are quite a gap, it's much cooler in Oct, this affect mpg, doesn't need to be cold like it is now. 

As said above, 1500rpm is quite normal to recharge hybrid battery and heat cabin, it's not like a normal engine where once warm, idles around 7-800 rpm. 

And yes 2.0 touring isn't very fuel efficient either. You have nothing to worry about, we have owned hybrid cars for a good number of years, we know what we're talking about this mpg thing. To achieve a bit higher mpg, need to turn off all heater in the cabin - no heated seats/steering wheel. Have to be a gangster like @Cyker

I'm afraid I wussed out and had to turn on the heating today!  

mpg is now down to only 66mpg! 66!! Totally rubbish! I'm taking the car back to Toyota and lodging lots of complaints at all the highest levels!!!!1!!1111one!1one!2eleven 

 

 

But more seriously yes the high 'idle' is normal; Really it isn't idling but trying to find work to do so it can provide heat so it will drive the wheels and charge the Battery. The engine is most efficient around 1500-2000rpm so it tries to stay in that zone

Also, weirdly, although the mpg is lower I have covered roughly the same distance per block on the fuel gauge so I am not sure how accurate the mpg reading actually is...!

 

[WALLOP]

I also own a 2022 Touring sport Excel 2.0 so can give some direct comparison figures. I have not reset the M.P.G readout since getting the car in March and during the summer months i was getting around 57.6 M.P.G and now that figure is down to 53.3 M.P.G. I am retired so a lot of my driving is local but the car has been on a few long runs up to Scotland and gets a good workout probably once a week. E10 petrol has always been used.

So your figures do look very low. My old Avensis 1.8 petrol estate was a heavy car and a little underpowered but that regularly returned 43M.P.G and up to 48 on a long run in summer. I think further investigation is required.

[Gray86]

Short trips in cold weather will see sub-40mpg. My trips this evening were around 32-35mpg. At the weekend I did a 50mile drive & got 54mpg. It’s normal 

[Cyker]

Yeah, I think one reason why mine is lower than this time last year is because I've been taking the shorter more congested routes home, due to the massive crack in my windscreen (Hopefully to be fixed on the 19th!!!  ), instead of my longer faster routes.

It does seem, even in a hybrid, that faster flowing routes are still more efficient than long runs of stop-start traffic!

[Carlosfandango]

Thanks all for the tips and advice - much appreciated!

[Obsidian Estate]

My mpg has dropped recently. In the warmer weather it was comfortably over 50, now I'm using the heating/ and what not a lot more it's dipped under 50.

Which to be fair is expected.

Though the colder weather didn't seem to massively affect my GT86. It would manage mid 30s no matter what.

The car that I had in the past that was most affected by the cold weather was a Peugeot 508 GT. Which was a 2.2 hdi auto. One Xmas after doing the usual fannying around to family and shopping etc I was greeted by a tank average of 22. Whoops.

I guess it wasn't happy with not getting hot properly.

[Mojo1010]

11 hours ago, Cyker said:

Yeah, I think one reason why mine is lower than this time last year is because I've been taking the shorter more congested routes home, due to the massive crack in my windscreen (Hopefully to be fixed on the 19th!!!  ), instead of my longer faster routes.

It does seem, even in a hybrid, that faster flowing routes are still more efficient than long runs of stop-start traffic!

With slower stop start traffic in winter especially, if using heating in cabin, it depletes the Battery and have to recharge more often. On faster road where the engine may be working for longer, it's already warm so provide free heat etc. 

Hybrid engines never 'idle', when it's on its because working, so it will never idle like a non hybrid @7-800. It took me some time to get use to the noise, still don't like the loud noise but that's how a hybrid works. Also for the OP, AC doesn't affect mpg much at all as the hybrid Battery provides that, not the engine. 

 

[Yugguy1970]

8 hours ago, Obsidian Estate said:

The car that I had in the past that was most affected by the cold weather was a Peugeot 508 GT. Which was a 2.2 hdi auto. One Xmas after doing the usual fannying around to family and shopping etc I was greeted by a tank average of 22. Whoops.

I guess it wasn't happy with not getting hot properly.

Diesel turbos always suffer from reduced mpg in the cold, cos this means denser air which means more fuel added.  Flipside is you do get a bit of extra power.  😁

[Roy124]

Yaris Cross - yesterday my car was outside all day and iced up when we went out.  Lights, heated seats, steering wheel, max defrost.  The journey to town and back returned about 54 mpg. 

The car was then garaged for an hour then driven in to town, lights, normal fan.  It returned 67 mpg, similar journey but less traffic at 7pm compared to 5pm.

On the longer figures, the average has been around 63 with December trending to high 50s.

[Parts-King]

It was minus 4 this morning here. I was sat at the traffic lights, heater on full, bum heater on go, and just happened to look at rev counter which was also on 1500 revs, or whatever that gauge actually means 🤦‍♂️

[TonyHSD]

AC affects the fuel consumption in summer, yes it uses hybrid Battery and the Battery charges from the engine which consumes petrol.
Now in the freezing cold even switched ON the ac will not work until the car engine bay reaches warmer temperatures 6C° and above. In cold temperatures is even better manually to turn off your ac, no need of it at all. Cabin heat, humidity control and fresh air will be supplied by the heater fan and best air to be intake from outside. 
Fuel consumption went down to 45mpg last two days because of the freezing temperatures and the Shell e10 I had didn’t help either, plus the fact I ve been keeping the car on for longer through the night. 

[Cyker]

9 hours ago, Yugguy1970 said:

Diesel turbos always suffer from reduced mpg in the cold, cos this means denser air which means more fuel added.  Flipside is you do get a bit of extra power.  😁

That's more of a petrol thing, as they measure air intake and add fuel accordingly.

Diesels run wide open throttle all the time and the accelerator directly controls how much fuel gets injected! They are usually turbo-charged too, so air density has very little effect compared to petrols. (That's also why turbo-charged engines don't have that very noticeable performance drop-off at high altitudes, as the turbo effectively controls the intake air density!)

The problem diesels have is they don't have spark plugs to ignite the fuel-air mix, and rely on heat from the compression stroke. When the engine is frozen, the engine block sucks up so much heat during the compression stroke that it will have trouble getting hot enough to ignite the fuel in the first place, which is where the glow plugs come in, but even once it's running, while the engine is still cold it sucks up a lot of the combustion heat and stops it pushing the cylinder down as forcefully, so it feels very under powered so you push the pedal in to add ore fuel etc. - That's why they can have worse mpg than a petrol engine when they're cold!!

It's worst in big solid iron blocks, as that is a LOT of mass to warm up to operating temperature!!

I found this in my Mk1 D4D - My mpgs cratered in winter initially as I was driving gently, and this meant the engine never generated much excess heat so it took forever to warm up. When my driving style changed to the more... enthusiastic... style I have now   , the engine warmed up much faster and I found I was getting near-summer mpgs out of it, even in winter, because it spent much more of the journey at operating temperature and could run at higher efficiency!

 

[Mojo1010]

I realised that when I got my first diesel car an Audi A3 1.6tdi which had 116ps I think. In the winter, drive it as fast as the condition and legal limit allows to get it up in temp and also to heat the cabin. It still got good mpg in the winter and generally all year around no matter how it was driven. Missed that from the diesel, torque of course also. 

[Cyker]

Don't worry, you can pretend you have that torque back when you get the Mk4

And in this weather the 3-pot sometimes sounds like a diesel engine so you'll be right at home!  

[Mojo1010]

My current 3 pot is actually louder than the diesel car I had. Gave a reminder this morning while I were scraping the ice from the windows and waited for it to heat up to clear the inside window. Heard the MK4 will be slightly lower in volume 🔊