Fuel Economy!

[philipac1948]

I have just bought a 1998 Avensis 2.0 GLS Saloon. When the Low Fuel Warning Light appears can anyone please tell me approximately how many gallons or litres are left in the tank. Also, what mpg should I expect. The car has done 67k miles, low for it's age.

[rosecott]

im proberly getting the least of all! i have a 1.8 vvt-i petrol engine with 53k miles and still only averaging 27mpg! must be something wrong!

I have a 2002 1.8 VVTi estate with 92k on the clock and am always loaded with golf bag and heavy electric trolley. I get a bit obsessed with the fuel consumption showing on the sat nav display and try to drive with the proverbiaL egg between foot and throttle pedal. I always drive to nearly empty, fill up to brim and check trip mileage to calculate consumption. The result is remarkably close to what it says on the sat nav display. I do mixed driving, some in towns, some on country roads and some A roads and motorways. I seldom drop below 40 mpg and usually between 40 to 42. I don't thrash it but sit at 70 on fast roads. I have no complaints whatsoever at this consumption in a big car with a huge boot.

[BenN74]

40mpg for a big car, heavy load is good.

I'm still working my way through my 50litres, bang on half a tank left now and I've done 202 miles and sat nav tells me 186 left.

One thing I have noticed is that I put some Redex 0-60 stuff in with this 50litres, and I my mpg readings have improved from allways being low 30's to now almost always reading mid 35 ish, and it seems to be climbing as t was on 34 last week, now reading 35's, hopefully it'll keep on rising, not sure what the stuff was, but it seems to have improved my consumption! (I'm sure that's a disease)

One other thing, MrDoody says in his blog that his mpg is about 30 and his car is using 6.6ltrs per 100km, so why does my sat nav say 35.5mpg but 7.9ltrs per 100km?? Surley that's wrong, I can't have a higher mpg and be using more diesel per 100km? Can anyone shed any light on this quandry?

Thanks.

:D BenN74 :D

Erm, oops, Doh, please ignore me, apologies, but I am kinda stoopid. lol Just read MrDoody's stats again and he actually said 6.6miles per litre, not 6.6ltrs per 100km, I'm still waiting till I run out of juice before posting my final stats from my 50litre test!

I can't complain wiv 35mpg really tho my friend has a 2ltr Golf GTI Mrk 4 that drinks petrol for fun, he gets about 20mpg!! He does drive like a loon tho, so he deserves it!

I just can't understand why soome cars, same year, similar milage can get 40's and 50's while mine is 30's?? Can anyone with more motor knowledge on me shed light on this?? Or is it simply a case of sme are in better shape, better looked after, or just lucky?

Does this Redex stuff work or am I just kidding myself? lol

Ta again!

[dr_roy]

My 2002 1.8 (petrol) gives me on average 38mpg according to the on-board computer. I can usually do about 120 miles/per quarter of the tank. I have been pretty close to 500 miles a couple of times. Mostly motorway/dual carriage way. However most evenings I get stuck on the M8 in Glasgow for at least 20-30 minutes...that really ruins the economy but nothing I can change.

The car has done about 74k.

[tczwoju]

Hi Guys,

I hope that you can help me.

I've been just following this subject and I think my mpg is very low as I have Avensis 2003, 2.00 litre VVTi ,T4 ,semi-automatic and my average is about 22.5mpg in mixed roads.It is about 12 litre per 100 km,is it not too much?I do get better mpg only when I'm driving on M3 or similar for longer time something about 35mpg.How to improve petrol usage on short distance or maybe it is not possible.Maybe my car has got broken something(I did not notice).If I will re-programm ECU with a new software,will it change anything?

Best

Wojciech

[allen2502]

Hi Guys,

I hope that you can help me.

I've been just following this subject and I think my mpg is very low as I have Avensis 2003, 2.00 litre VVTi ,T4 ,semi-automatic and my average is about 22.5mpg in mixed roads.It is about 12 litre per 100 km,is it not too much?I do get better mpg only when I'm driving on M3 or similar for longer time something about 35mpg.How to improve petrol usage on short distance or maybe it is not possible.Maybe my car has got broken something(I did not notice).If I will re-programm ECU with a new software,will it change anything?

Best

Wojciech

hi dude, i get an average of 22.0 to 26.5mpg 53 2.0ltr vvti spirit, it is a semi auto so that could be why its a little steeper?

[BenN74]

Hi Guys,

I hope that you can help me.

I've been just following this subject and I think my mpg is very low as I have Avensis 2003, 2.00 litre VVTi ,T4 ,semi-automatic and my average is about 22.5mpg in mixed roads.It is about 12 litre per 100 km,is it not too much?I do get better mpg only when I'm driving on M3 or similar for longer time something about 35mpg.How to improve petrol usage on short distance or maybe it is not possible.Maybe my car has got broken something(I did not notice).If I will re-programm ECU with a new software,will it change anything?

Best

Wojciech

I think the reason you fuel economy is so low is just due to the type of vehicle you have, petrol are less economical than diesel and auto's are less economical than manual, so I presume semi-auto's are in the middle. Not much help I know, but I don't think your car is broken, and I'm not sure there is a grat deal can be done to improve it! Sorry! Just try taking it easy on the throttle, try to time your driving to avoid stopping at lights, there's a list of small things like this on 'Kingo's' site I think, have a look!

BTW, I'm down to a quarter tank now from my 50litres, and I've done 260miles approx, so I'm thinking about 370 ish for my 50litres, not great, but better tan somw, I think kinda middle of the road figures, all of this driving has been done in town aswell, I have Thursday off, I mite take it for a run down the m62 just to see what the difference is.!

:D BenN74 :D

[Bino]

I have a Dec 2006 T3-X D4D. Normal motoring, which includes a bit of everything will consistently return 45 to 47 MPG. I have calculated the MPG by hand and found that the computer is only marginally out. Last week I drove from Devon to Ipswich and back and returned 54.6. The cruise was switched on from Birmingham to Exeter on the return leg. Since I have had the car (3 months) I have founds that tyres presures make a hugh difference and that the car does not really settle down until it has reached tempreture. Overall, i'm chuffed to bits wit the economy as my previous car (carolla T-Sport) was only giving me 29 MPG. I never trust what is in the manual....I guess they use a clean, empty car with no wind resistence etc. I also drive the car the car to the road conditions, ie fast when approriate and slow when not.

[JohnYossarian]

I have a Dec 2006 T3-X D4D. Normal motoring, which includes a bit of everything will consistently return 45 to 47 MPG. I have calculated the MPG by hand and found that the computer is only marginally out. Last week I drove from Devon to Ipswich and back and returned 54.6. The cruise was switched on from Birmingham to Exeter on the return leg. Since I have had the car (3 months) I have founds that tyres presures make a hugh difference and that the car does not really settle down until it has reached tempreture. Overall, i'm chuffed to bits wit the economy as my previous car (carolla T-Sport) was only giving me 29 MPG. I never trust what is in the manual....I guess they use a clean, empty car with no wind resistence etc. I also drive the car the car to the road conditions, ie fast when approriate and slow when not.

I second the tyre pressure importance. Even 0.2 bar difference from prescribed (2.4 bar for my Avensis T3-X) makes significant dip in the economy.

[groovyG]

I have a Dec 2006 T3-X D4D. Normal motoring, which includes a bit of everything will consistently return 45 to 47 MPG. I have calculated the MPG by hand and found that the computer is only marginally out. Last week I drove from Devon to Ipswich and back and returned 54.6. The cruise was switched on from Birmingham to Exeter on the return leg. Since I have had the car (3 months) I have founds that tyres presures make a hugh difference and that the car does not really settle down until it has reached tempreture. Overall, i'm chuffed to bits wit the economy as my previous car (carolla T-Sport) was only giving me 29 MPG. I never trust what is in the manual....I guess they use a clean, empty car with no wind resistence etc. I also drive the car the car to the road conditions, ie fast when approriate and slow when not.

Mine's a D4D 54 plate; I've found that the consumption shown by the computer is usually around 58 mpg, whereas calculating from brim to brim, either on successive refuellings or over a longer period, the true figure is about 47 mpg. Since buying this 2nd hand 3½ months ago, the computer seems to have learned that the achievable range on a full tank approaches 600 miles - on the first fill up after I bought it, it thought the range was a lot less than that. (Presumably, previous owner got poorer fuel economy than I'm currently getting, therefore shorter range on a full tank.)

Anyone have any ideas, if the computer can get the range right, how it can be persuaded to give a more accurate average consumption figure?

[JohnYossarian]

I have a Dec 2006 T3-X D4D. Normal motoring, which includes a bit of everything will consistently return 45 to 47 MPG. I have calculated the MPG by hand and found that the computer is only marginally out. Last week I drove from Devon to Ipswich and back and returned 54.6. The cruise was switched on from Birmingham to Exeter on the return leg. Since I have had the car (3 months) I have founds that tyres presures make a hugh difference and that the car does not really settle down until it has reached tempreture. Overall, i'm chuffed to bits wit the economy as my previous car (carolla T-Sport) was only giving me 29 MPG. I never trust what is in the manual....I guess they use a clean, empty car with no wind resistence etc. I also drive the car the car to the road conditions, ie fast when approriate and slow when not.

Mine's a D4D 54 plate; I've found that the consumption shown by the computer is usually around 58 mpg, whereas calculating from brim to brim, either on successive refuellings or over a longer period, the true figure is about 47 mpg. Since buying this 2nd hand 3½ months ago, the computer seems to have learned that the achievable range on a full tank approaches 600 miles - on the first fill up after I bought it, it thought the range was a lot less than that. (Presumably, previous owner got poorer fuel economy than I'm currently getting, therefore shorter range on a full tank.)

Anyone have any ideas, if the computer can get the range right, how it can be persuaded to give a more accurate average consumption figure?

I noticed something similar after driving my T3-X D4-D for almost six months (03 second hand). The onboard computer would get the economy at 51 mpg but as I fuel the car up after I had spend about 50 l it started to get closer to the regular 45-47 mpg (combined 50:50) consumption. I do not know if the computer gets a bit dizzy if one did add 10 l now and 15 l later instead of fuelling up to the top.

When I fill it to the top the computer zeroes itself. Does it do the same if you simply open the cap up? In the latter case it should not matter how much you add I guess.

[BenN74]

Hi,

Right, finally used the 50litres now almost, my red light(well orange really) has now come on and my satnav says I've got about 29miles cruising range left, I've done 315 miles only tho which gives me

50litres - 345miles

6.9miles per litre

50litres = 10.99gallons

Average Consumption = 31.32mpg

Now this has surprised me because the ecu reads 34-35mpg always, never below 34mpg, so why is it wrong? Also when I first topped up my ecu estimated 397 miles cruising range, yet I've got nowhere near that, and I don't drive erratically, or at speed?? Saying that though, all the 50litres has been in the city, so maybe the ecu calculated my range with a mixture, which thinking about it now makes sense, so that is probably why I've got less miles than the ecu estimated, but I don't know why the average mpg is lower than what it always reads?

Does the ecu work it out right down to empty or would I get more than the 29 miles it says? And is there a way to stop it re-setting every time I stop the car, and give you an average mpg over a longer period than just your current trip.

I'm really kinda disappointed with the figures I have got tho, I'm going to have to take her down the M'way this week and see how much of a difference it makes!

I'm going to fill it up to the very brim this time (which should be 60litres) and see if this next tank is any better cause I had some of that redex 0-60 stuff in this tank, and to be honest it does seem to have made a slight(only slight) difference. The satnav/ecu used to always read 33/34mpg, now it seems to be stuck on 35mpg, so much so I'm a little worried it's broke, lol! Maybe it's my driving is more atuned to the car now, I did only buy her 31st Jan, rather than the additive, I'll see how she runs on this next tank!

Disappointed with only 345 from 50litres though. Maybe I need to start using 5th gear, kinda hard just round town tho. lol

[Mrdoody]

Remember your car will only work out the average fuel economy. The simple calculation is done by dividing the distance travelled since you last reset the counter, by the fuel that's been used in the tank since you last reset the counter.

The best way to get the most accurate reading on your MPG consumption is to reset the MPG calculator as soon as you fill up. Then see what it finishes at when the tank is empty.

You can normally do this by selecting the MPG indicator on the sat nav display and then pressing and holding the button underneath to the right of the display until it goes to zero.

The further you travel the more accurate the reading will be. The logic behind this is, if you reset it and then travel 1 mile uphill. you're likely to get a really low MPG reading becasue for that 1 mile distance you've been using lots of fuel powering uphill. On the other hand if you reset it and then rolled down a bank for 1 mile, the reading would be sky high cos you aint used hardly any fuel to travel that distance.

Hope that helps.

And for the record since my last post, I've re filled the tank completely and got it to emply again and got 340 miles this time around. A deficit of 20 miles from the last full tank. Perhaps we all need to go on a diet lol.

[DodgyKnee]

My petrol 2.0 litre seems to give about 380 miles from a tank and I always wait until both the orange light is on and the petrol gauge reads empty. But having said that, I have never been able to fit more than about 50 litres in, even with some ridiculous brimming. As the tank holds 60 litres, this must mean there are 10 litres in the system somewhere - I wonder if it's useable. The only way to know would be to run the car until it stopped due to fuel starvation, but this would be a bit daft (and maybe cause some crud in the bottom of the tank to clog the injectors). Maybe the ECU estimation of mpg makes takes some account of this 'reserve'.

[BenN74]

The best way to get the most accurate reading on your MPG consumption is to reset the MPG calculator as soon as you fill up. Then see what it finishes at when the tank is empty.

You can normally do this by selecting the MPG indicator on the sat nav display and then pressing and holding the button underneath to the right of the display until it goes to zero.

Hi MrDoody,

Can you explain this to me, I may be just being stupid, but there do not seem to be any buttons anywhere near my sat nav, apart from 'tilt' and 'close/open' and neither of these re-set the mpg??

I would like to be able to stop the mpg re-setting everytime I stop the engine, case as you say over a longer distance you would get a much beter estimate of your fuel usage!

I have the colour sat nav screen that flips up out of the dash, I need to start this, go into info, then trip info and everythings there, I can't seem to see ay options to stop it re-setting, there is a change units button and re-set, is this the one you mean?

Thanks!

[Groovy Mucker]

Ben

You press and hold the selector button on your steering wheel, having selected "Average mpg". You can reset the av speed in the same way. You can even do it while travelling.

It's a way of getting the average on a tankful, but these computers are notoriously unreliable and the best way is the brim-to-brim method.

[f891roy]

Mine's a T3X 2.0l D4D 54 plate (december). i always drive until the orange light comes on. fill her to the brim and was getting between 495-515 miles!! 515 miles was the most ever. i now work 9 miles from my house and i get between 460 - 470 miles!! a bit less than when i drove 64 miles round trip to/from work!!

[Leeds fc]

I filled up my car,(SR VVT-I 2.0), today at a cost of 53.80. Last month i got 27.4 mpg at an average 26mph.300+ miles a month. I do a lot of town driving. I would say that i do about 10 miles out of town driving a week day, but the 3 roundabouts each way :ffs: do slow me down.

[gutsysean]

Hello,

I have just registered today and have been reading some of your entries relating to fuel economy.

I have a 2sr vvti 2001, i have found that my vehicle is doing around 23-25 mpg, mind you i do live on top of a mountain and with two teenagers i am often doing short trips up and down the hills.

I am not happy with this. I have had the car for three years and fair play its been brill up to now. I have been told to change the fuel filter as it has lost some of its power, saying that apart from a home service two years ago i have not touched it.

[BenN74]

Hi,

I really don't know whether I'm just getting more used to the car, and as a result driving it more economically, or possibly the redex 0-60 stuff did summat but my mpg keeps improving?? It was almost always reading about 34mpg a few weeks ago, then that rose to 35.3 ish, then about a week ago I noticed for most trips it was reading 36.5 and today after a 15mile trip round town I got home and checked and it read 39.9mpg?

I went out to the dales at tea time and on the trip back it read 43mpg, but that's probably cause I was driving on by-passes most of the way.

If I can get the economy to read 40mpg round town on most trips I'll be more than happy.

I got about 350ish miles from 50litres last time, I'm gonna fill it to the brim tomorrow, which should be 60litres, and see how many miles I get from that. I am really curious as to why the economy seems to be getting slowly better though! lol

By the way, when you say hold the selector button on the sterring wheel?? I use a little remote control thingy to control the sat nav, and the trip computer, it clicks into a housing under the hand brake, the only control on my wheel is the voice control button, and radio ones on the other side. I think maybe you have a different system to me? I have an instruction book for it somewhere, I'll dig it out and see if that tells me how to stop the trip info re-setting on every trip!

But in the meantime I'll do it manually, brim to brim as that's probably more reliable and acurate anyway!

[BenN74]

Hi,

Just had another thought, does diesel differ from different garages, or is diesel same wherever it's from.

I tend to get mine from morrisons (save the points for my £5 vouchers, lol) But a few posts I've read have dissed 'supermarket' diesel.

So is the quality different in supermarkets to that which you'd get at a big name garage?

I think I mite try a tank from esso or the like and see if there is a difference on fuel economy and performance.

Does anybody else have any thoughts on this?

:D BenN74 :D

[JohnYossarian]

Hi,

Just had another thought, does diesel differ from different garages, or is diesel same wherever it's from.

I tend to get mine from morrisons (save the points for my £5 vouchers, lol) But a few posts I've read have dissed 'supermarket' diesel.

So is the quality different in supermarkets to that which you'd get at a big name garage?

I think I mite try a tank from esso or the like and see if there is a difference on fuel economy and performance.

Does anybody else have any thoughts on this?

:D BenN74 :D

I have to agree with the supermarkets' diesel quality issues. I have used Sainsbury's station twice (I have always used BP by far) and I will never ever approach a supermarket station again! Yesterday, on my way back from Yorkshire the car was obviously underpowered. No matter how much i was pushing the pedal the car would not move faster. The power had gone. I have never had such experience before, when on BP fuel.

I only hope that I have not blocked the injectors and the rest of the delivery system and that a fresh refill (later today) with BP diesel would resolve the problem. I should have never approached it in the first place, but I was waiting for someone and found myself near the station. Stupid move indeed.

Cheers,

John

[BenN74]

Hmmm, right

I think I'll have to deffinately stop using Mr M's diesel then.

You recommend BP yeah, I'l try that.

BTW, went out for a drive today and my sat nav read 42.7mpg, either the silly things broken or my economy is improving? lol

I'll have to fill her up and check i manually!

Are these 'Premium Diesels' anygood? Or should I just use standard diesel but from a good brand garage??

Thanks!!

[ptri]

My calculation of mpg based on brands gives:

Brand (diesel %) +/- average mpg

Total (3%) +4.2%

Unknown (1%) +0.9%

Sainsbury (15%) +0.7%

Tesco (48%) +0.1%

Total (Excellium) (6%) -0.5%

Shell (26%) -1.0%

I have only bought Shell, Tesco & Sainsbury fuel in significant quantities. As I've bought more Shell over the winter, the difference from Tesco is probably more due to cold weather. (Note that the Total Excellium was bought abroad where my driving pattern was different.) I therefore can see no significant difference between these brands. Cleanliness of fuel is another matter, but I suspect differences are more due to individual garage tanks and tankers rather than brands.

[BenN74]

Hi,

I think that it may be correct that the 'supermarket diesel' isnt quite as good.

I usually get around 120miles from 20litres.

I put 20 litres in from esso and it did 150miles, granted some of this was out of town, driving to skipton, so I would expect it to be higher, but that is a big increase.

I have now tried a ful tank, 50lts, from BP and I'll see if I get much more than the 360miles Mr Morribogs diesel gave me for 50litres previously.

I am amazed with the difference in economy from town driving to motorway driving aswell, my car at the moment registers around 38/39mpg on my sat nav when driving round town, I filled her up this evening and went to pick my Ma up, which involved a trip of about 15miles, probably 50/50 M'way and town roads, but it was late, 11pm, when I arrived it was reading, 49mpg!! Quite an increase I think. If I'd took a longer trip down the M'way I bet it would have gone higher aswell.