Impossible Mpg?

[IanLorenc]

Picked up my 98 S 1.8 Avensis GLS saloon a few weeks ago and I'm perfectly satisified with it. Very quiet, very comfortable and in the colour I have (Baltic??) very stylish, I think.

Anyway.

Whenever I change car, I always like to know what my new car is doing to the gallon. So fill her up to the brim, reset trip meter, drive normally for a while then brim her again. Divide the miles on the trip meter by the fuel used (how much you have to put back in again to brim it) et voila. I worked out that for my normal commute and day-to-day use, she was doing just over 34mpg which I think is about right.

Anyhoo.

I took her out for a run on Sunday so I thought I'd see what she'd manage on a run. I was predicting 42-44 mpg, which I would have been happy with. Brim her before I leave and reset the trip meter. Go out, come back and brim the tank again.

Here's my maths:

Filling her tank completely again when I got back, cost £17.60, which at 86.9p a litre, meant I got 20.253 litres. Let's convert that from Euro speak into English.

20.253 litres divided by 4.546 = 4.45 gallons.

(Conversion Table)

Okay. The trip meter said that I'd done 245.1 miles.

Here's the part I'm trying to get my head around:

If you divide 245.1 miles by 4.45 gallons, it means that I'd supposedly got 55.07mpg.

I know I was going steady (55-65mph) and the car has only done 41500 miles but is this possible? A few people I've spoken to say that it isn't and I think I'm inclined to agree. I've gone over the sums several times though and can't see anything wrong. What is everyone else getting to the gallon?

[JAHill]

Well, your working looks fine ;), I get 55.02 which is close enough... Has the car got the correct size wheel/tyre combination? Just in case this is throwing out the odometer. I would love to get 55mpg in mine. I get about 42mpg and I've got a two litre diesel! :( But I live in a "Red Light District" with twisty roads... and not in a good way :D

55mpg, even for a 1.8 sounds a bit high.

[IanLorenc]

The wheels/tyres are the standard fitment ones so should be no problems there.

The people I spoke to said that 55 would be possible in a diesel on a run but not a 1.8 petrol.

The maths look sound so there's only three other possible explanations:

1. The tank wasn't completely full. I filled it so that the level came over the flap. The level did not then lower when I poked the flap up with the pump nozzle and I did wait for about 10 seconds. According to some quick recalculations, to get 42mpg, it would have taken £23.05 to fill it back up and I estimate that I could maybe have got another 6 or 7p in, 10p at most; certainly not another £5.45. An extra 10p would drop it to 54.70mpg BTW. This therefore rules this explanation out

2. Witchcraft. I don't dabble in the black arts so this is discounted.

:hokus-pokus:

3. Motoring karma. Must be this one. My 8 years and 11 months of driving like Sister Wendy must finally be paying off.

[JAHill]

3. Motoring karma. Must be this one. My 8 years and 11 months of driving like Sister Wendy must finally be paying off.

Damn... That must be where I'm going wrong... That leaves me with The Black Arts! :hokus-pokus: ;)

[Rene]

My previous cas was a 1996 1.8 Carina E. This one must have had the same lean-burn type of engine. On a very long trip (750km) i was able to make a 17.9km/l (42.5mpg i think). Speed 120km/h, speeding up like grand-ma, wind in the back (same distance with wind in the front 39mpg). I don't think there are many cars of same size and 1.8l engine reaching this result. Your 55mpg looks like wichcraft to me. I hope you won't be dissapointed next time you fill up your tank.

[IanLorenc]

3. Motoring karma. Must be this one. My 8 years and 11 months of driving like Sister Wendy must finally be paying off.

Damn... That must be where I'm going wrong... That leaves me with The Black Arts! :hokus-pokus: ;)

They're both fine choices, whatever floats your boat.

Your 55mpg looks like wichcraft to me. I hope you won't be dissapointed next time you fill up your tank.

Don't worry, I shan't expect that kind of economy again and if you don't expect something, you'll never be disappointed.

[Steve84]

My dad had 50 mpg out of his lean burn avensis with ease, His vvt-i is doing 45-47 along with mine. Talking to a tech at work who is toyota trained even he has had people comment on how good on fuel the 1.8 lean burn was and that the vvt-i is not far behined.

[Chris Dance]

My son is getting 53 MPG on his 03 1.8 Avensis. He uses only optimax fuel though.

On my T4 2litre 53 Avensis I am getting 36MPG at the moment but in the hotter weather I get over 40MPG. using low grade fuel mostly from Tesco.

[DVH]

53 2ltr spirit, 4 adults + luggage 39mpg with cruise set to 80mph travelling through the night through europe.

general use round town once warmed up 36 general use motorways etc 42. any old fuel

I am more than pleased with this, used to have a ford cmax 2ltr diesel best it could manage 40mpg, on a run but averaged out at 33--36 was not at all impressed.

[gtyatton]

I would say your fuel consumption is about right.

To the amusement of other family members, I also keep a note of fuel and miles. I have a 2002 vermont vvti 1800 petrol with 30k on the clock. She does 42 mpg knocking about locally and if I slip over to the Lake District, about 100 mile trip, my fuel consumption will be about 52 mpg. I'm quite happy with it. Next week end, I'm going up to Inverness- 700 mile round trip. Yes I will be jotting down my fuel and mileage as usual. If my miles drop to 35 mpg, either I'm leaking fuel or I'm wearing my hiking boots!

[Rene]

Have to correct my previous message. Had converted my km/l to US mpg. Converted to UK mpg, 17.9km/l equals to 50.5mpg. Looks more like the numbers above...

[thiambal]

Hmmmm. I have a 2000 1.8 Vvti and I am only getting an average of about 36mpg mixed motoring using non-supermarket 95 pertrol.

Although it is cold at the moment that seems a lot less that the figures of 45-7 being quote here. Should I be worried?

[IanLorenc]

Interesting comments there from everyone. Thanks for that. Has to be the first time I've heard of a car doing more to the gallon, than the manufacturer claim.

I can live with that though. I'll just have to do more runs.

Hmmmm. I have a 2000 1.8 Vvti and I am only getting an average of about 36mpg mixed motoring using non-supermarket 95 pertrol.

As I mentioned, I'm only getting 34mpg on the daily grind (which for me, is more 50-60mph country B roads than town stop-start). I'm also using just boggo 95 petrol from Sainsbury's.

[thiambal]

Interesting comments there from everyone. Thanks for that. Has to be the first time I've heard of a car doing more to the gallon, than the manufacturer claim.

I can live with that though. I'll just have to do more runs.

Hmmmm. I have a 2000 1.8 Vvti and I am only getting an average of about 36mpg mixed motoring using non-supermarket 95 pertrol.

As I mentioned, I'm only getting 34mpg on the daily grind (which for me, is more 50-60mph country B roads than town stop-start). I'm also using just boggo 95 petrol from Sainsbury's.

Few - yep that was just me not read the previous post carefully. I am doing a long motorway only run in a couple of weeks. I will report back on how we do.

P.S. I once got 59 mpg ave just after filling up - but I think that was mainly to do with going down a long hill :D :D . I assume this means if I am traveling from north to south I will use almost no petrol as it is clearly all down hill to the south :D

[IanLorenc]

Repeat perfomance.

I'd just worked out another day-to-day MPG at 38.18mpg (31.15 litres / 4.546 = 6.852 gallons - 261.6 miles / 6.852 gallons = 38.18mpg).

Then, at short notice, I had to do another run today dropping my brother off to pick up his new van. This was the perfect opportunity to see if the last run of 55.07mpg was a fluke. Here's the maths:

Fill tank before starting. 10.01 litres required to fill the tank back up afterwards. 10.01 / 4.546 = 2.202 gallons. 118.3 miles / 2.202 gallons = 53.72mpg.

Result.

:D