2010 T27 Avensis 1.8 TR Valvematic petrol fuel economy

[MikeEH]

I acquired my 2010 Avensis 3 years ago next month with 54K miles on the clock. Since then my mpg has varied between 32.2 and 32.6, both town and motorway driving. My type of driving has not changed since I had my previous car, a T25 Avensis 1.8 petrol. Yet, during the 4 years of driving the T25, the mpg varied between 29 and 53.2. I have worked out the mpg by filling the tank and checking the mileage then re-filling, etc., and it worked out to approx 33 -34mpg. Is there anyone out there with a similar Avensis who is getting similar mpg as I am? If so, what would be the main difference between the T25 and T26 engines that would give such extreme differences in mpg?

[Konrad C]

I am getting 35mpg average with mixed driving within Greater London. Where I live is hilly. I use my car less (2 or 3 times a week), so only top up once a month on average with quarter of a tank remaining. I have not noticed any difference in economy or performance using E10, since the car/engine was designed to use that fuel. Longer journeys if I do them, see the car into the 40's mpg. My car is a 2009 Valvematic Tourer manual on 100,000 miles. The big change is that I have a full size alloy as a spare wheel. Space saver is in the shed.

[TonyHSD]

The E5 petrol may help reduce the fuel consumption particularly during the cold months. Any temperature lower than 12C° the E5 wins vs E10 95. I noticed that last winter and noticed again this autumn when temperatures were down to 4C° at night few weeks ago. You can try E5 99 from Tesco or BP, Esso, Shell and see if any improvements. The difference won’t be huge but around 3-5mpg. 

[Konrad C]

On 10/29/2022 at 9:58 AM, TonyHSD said:

The E5 petrol may help reduce the fuel consumption particularly during the cold months. Any temperature lower than 12C° the E5 wins vs E10 95. I noticed that last winter and noticed again this autumn when temperatures were down to 4C° at night few weeks ago. You can try E5 99 from Tesco or BP, Esso, shell and see if any improvements. The difference won’t be huge but around 3-5mpg. 

Additionally, info suggests there is more moisture produced with E10 fuel, especially during the winter! I Googled E10 has more moisture and this was one of the results - One problem with E10 added to gasoline is moisture, because ethanol absorbs water like a sponge; moisture from its surroundings, air, condensation and storage practices all contribute to engine problems, hard starting, stalling at both high and low speeds, misfiring, or just refusing to run or start at all.

So to reduce this, I will need to use the car more or use E5 fuel. 

[Cyker]

It's not great, esp. if the car is sat for long periods (Like weeks) as the water will start to settle out to form a layer at the bottom.

Esp. in older petrol tanks which aren't sealed to atmosphere like newer ones are.

It boggles my mind that nobody considered water absorption and ingestion being a potential problem for engines when they certified this stuff!!

 

[MikeEH]

Thanks for replies. I've had this low, in my opinion, mpg since I bought the car in 2019, pre-E10 days, I've re-set the mpg display on numerous occasions and mathematically worked out the approx mpg from mileage/filling tank operations but still cannot get more than 32.6 (display), 34 (mileage/filling tank) which was experienced on an M4 trip of 80 miles. When I was doing the same 80 mile trip in my old T25, I was getting 49-50mpg. Is there such a difference in the engine workings of the T25 and T27 that would cause this huge difference in mpg?

[Cyker]

Is the T27 1.8L as well...?

Typically newer Toyota engines get more efficient the newer they are so I'd be surprised if it was something inherent to the car.

My first thoughts are the condition of the car - What's the tyre pressures, oil condition, spark plug condition, air filter condition etc. all like?

 

[TonyHSD]

Could be something to do with the weight, if the T25 lighter than T27?
My relative has T25 2.0 petrol manual, those who should not be run on E10 but he does and his car is very economical. I have seen myself previously very good numbers on the dashboard while he was driving sensibly. 

[MikeEH]

The T27 is a 1.8L as well. Car is kept to (better than) recommendations - tyre pressures correct, oil change every 6K, Iridium plugs every 12K, air filter every 20K. I'm a quite sharp 73 year old who is not a pretend boy racer and I treat my cars with respect - hence, I believe, the good economy I was getting with the old T25. Would it be worth getting the engine checked at one of those mapping centres I wonder?

[JARC1]

2012 Avensis T 27 2.0 Diesel.

Which, having read above discussion, are you recommending I should use in my recently acquire Car ?

Thanks and Best Wishes, John

[Cessna]

There does appear to be something wrong MikeEH. I have a 2015 1.8 petrol T27 estate. Like Konrad, mixed driving in London gives me 35mpg or so. Out on the motorway I get 40mpg or more. If I take it really easy and do 60mph (not often!), I easily get over 45mpg.

Given your driving style and that it's well maintained, I am struggling to think what else it may be. You say that you got 34mpg on an 80 mile journey on the M4, by filling the tank and noting the mileage. That is obviously a good way to measure it, but maybe try it a few more times in case the first fill on this specific journey wasn't quite to the top of the tank due to the auto shut-off activating early, differences in nozzle, being on slight slope etc.

 

[MikeEH]

Even though I worked it out at 34mpg for the 80 miles by filling the tank and noting the mileage, the mpg display still only showed 32.6mpg.

[Cessna]

4 hours ago, MikeEH said:

Even though I worked it out at 34mpg for the 80 miles by filling the tank and noting the mileage, the mpg display still only showed 32.6mpg.

I did notice that in your post above, but I thought it worth trying a few times just in case. But I agree, the mpg display showing that does indicate that the filling and mileage were pretty accurate.

Although the car has an excellent service history, has the work actually been done? Might be worth having a look at the air filter to ensure it is relatively new and not an old clogged-up one (and that squirrels haven't used the air filter box as a nut store!).

[MikeEH]

Yes, the work has been done. If I don't do it myself, I get my friend from my old schooldays to do it, who always gives me the old parts. Checked the filter - it's still clean.