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High Fuel Consumption


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I've just accurately calculated my fuel consumption.

I spent £41 which is 43.66 litres and got 412 miles, if I did the sums right that equates to 43mpg (UK gallon)

That's with a mixture of motorway miles and town driving, quite a few cold starts with short journeys, an MOT, aircon on and off as required, and I lent the car to my dad (different style of driving) for 60 miles.

Better than I thought.

thats outstanding... how on earth did you manage it?

you must have been very very froogle.

50mph/6th gear lane 1 motorway driving?

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I've just accurately calculated my fuel consumption.

I spent £41 which is 43.66 litres and got 412 miles, if I did the sums right that equates to 43mpg (UK gallon)

That's with a mixture of motorway miles and town driving, quite a few cold starts with short journeys, an MOT, aircon on and off as required, and I lent the car to my dad (different style of driving) for 60 miles.

Better than I thought.

thats outstanding... how on earth did you manage it?

you must have been very very froogle.

50mph/6th gear lane 1 motorway driving?

No not really, I just tend to put my foot down as required, straight into fast lane on mway, tend to sit around 80.. I also drive most of the time with the traction control off, but that shouldn't make a great difference, and use Asda unleaded 95RON.

I think the ECU has properly adapted to my driving style, car as been serviced regularly and is top condition.

I'm still pleasantly suprised by the consumption though. :)

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I've just accurately calculated my fuel consumption.

I spent £41 which is 43.66 litres and got 412 miles, if I did the sums right that equates to 43mpg (UK gallon)

That's with a mixture of motorway miles and town driving, quite a few cold starts with short journeys, an MOT, aircon on and off as required, and I lent the car to my dad (different style of driving) for 60 miles.

Better than I thought.

I'm not trying to say your making this up but I have to ask. Are you sure that the 412miles wasn't from your full tank i.e. just over 60 litres. If so that would be 31.7mpg which would in it'self would be impressive but a lot more understandable.

I don't think anyone has claimed 43mpg before. Even cruising on a motorway at 80mph the guage will only barely make it to above 40mpg.

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I'm not trying to say your making this up but I have to ask. Are you sure that the 412miles wasn't from your full tank i.e. just over 60 litres. If so that would be 31.7mpg which would in it'self would be impressive but a lot more understandable.

I don't think anyone has claimed 43mpg before. Even cruising on a motorway at 80mph the guage will only barely make it to above 40mpg.

I know what you mean, that's why I thought I had miscalculated at first.

I put fuel in when the needle was on the 1/4 mark, I put £41 in which took the gauge upto just under the full mark, reset the trip to 0 and when the needle reached the 1/4 again I had done 412 miles.

I also calculated it at the approximate mid point and that gave 37 mpg. I must admit I does sound very high. I'll shall keep doing it and see what I get.

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Mine does 19 to 20 miles/gallon. 2001 IS200SE auto with 112000 miles on the clock, all city driving. My previous C180 was thirstier yet it was underpower. So not bad for me.

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I'm not trying to say your making this up but I have to ask. Are you sure that the 412miles wasn't from your full tank i.e. just over 60 litres. If so that would be 31.7mpg which would in it'self would be impressive but a lot more understandable.

I don't think anyone has claimed 43mpg before. Even cruising on a motorway at 80mph the guage will only barely make it to above 40mpg.

I know what you mean, that's why I thought I had miscalculated at first.

I put fuel in when the needle was on the 1/4 mark, I put £41 in which took the gauge upto just under the full mark, reset the trip to 0 and when the needle reached the 1/4 again I had done 412 miles.

I also calculated it at the approximate mid point and that gave 37 mpg. I must admit I does sound very high. I'll shall keep doing it and see what I get.

Humm, not the most accurate way of doing the test i dont think.

what you should do is

- fill the tank to the brim

- reset your trip counter

- drive around

- go back to the pump

- fill the tank up to the brim again....

....and however many ltrs went in, work it out with the number of miles on your counter, never having to worry about the needle position, which i beleive we have all found to be inaccurate.

give that a go next week, and report back.

either way, your doing a great job with your mpg, easily one of the most econimical IS's. [source: http://www.spritmonitor.de/en/overview/26-...km=0&sort=1 ]

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I calculated mine by waiting for the petrol warning light to come on, fill it up with 20litres of fuel then wait till the warning light comes on again then calculate the consumption. Did it 3 times then got the average, 19-20mpg.

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I always measure by filling to the brim, resetting odometer and then running it dry- getting 21 mpg.

I would love to know what those who are getting excellent mpg have done to their car- where serviced, wheels aligned, etc?

ie. most notably, trevman and Ivanovoitch. Please take some time to take us through your cars basic history and any notable elements e.g. wheels aligned, parts changed.... etc.

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I'm getting about 25-27mpg, this is mostly city driving, with lots of stop/start traffic and also dual carriagaway driving. 2000 model IS200 with 90k on the clock.

I'm also inclined to believe that mpg improves as your car gets older, the engine will loosen up. Some people on here in the past have reported that their IS's drive much better with 100k + on the clock.

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I'm not trying to say your making this up but I have to ask. Are you sure that the 412miles wasn't from your full tank i.e. just over 60 litres. If so that would be 31.7mpg which would in it'self would be impressive but a lot more understandable.

I don't think anyone has claimed 43mpg before. Even cruising on a motorway at 80mph the guage will only barely make it to above 40mpg.

I know what you mean, that's why I thought I had miscalculated at first.

I put fuel in when the needle was on the 1/4 mark, I put £41 in which took the gauge upto just under the full mark, reset the trip to 0 and when the needle reached the 1/4 again I had done 412 miles.

I also calculated it at the approximate mid point and that gave 37 mpg. I must admit I does sound very high. I'll shall keep doing it and see what I get.

Humm, not the most accurate way of doing the test i dont think.

what you should do is

- fill the tank to the brim

- reset your trip counter

- drive around

- go back to the pump

- fill the tank up to the brim again....

....and however many ltrs went in, work it out with the number of miles on your counter, never having to worry about the needle position, which i beleive we have all found to be inaccurate.

give that a go next week, and report back.

either way, your doing a great job with your mpg, easily one of the most econimical IS's. [source: http://www.spritmonitor.de/en/overview/26-...km=0&sort=1 ]

As Vyker says this is the only way to work out your mpg accurately. I get 15mpg during the winter doing mostly short journeys (under 10 miles) in town. In summer I get around 21mpg. If I do some motorway driving I end up getting around 27-28mpg but then again I am driving an auto. Had the same problem with my auto honda accord.

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I always measure by filling to the brim, resetting odometer and then running it dry- getting 21 mpg.

I would love to know what those who are getting excellent mpg have done to their car- where serviced, wheels aligned, etc?

ie. most notably, trevman and Ivanovoitch. Please take some time to take us through your cars basic history and any notable elements e.g. wheels aligned, parts changed.... etc.

Well, I brought the car 3 years ago from a Lexus dealer, it had 21k on the clock and had just had it's 20k service and an RAC inspection. Lexus fitted 5 new alloy wheels (as the old ones were starting to corrode) and four new Bridgestone Potenza tyres.

The car hasn't been modified in any way, I've never had any geo/alignment done as it handles fine and tyres don't wear uneven or excessively. I've always serviced the car myself following Lexus schedules exactly, everything done correctly right down to torque values. It's garaged at night, washed and polished regularly, and that's it.

I am getting far better consumption now than when I brought the car, at first it seemed to be a real heavy drinker.

I filled the tank yesterday so I'm gonna recalculate fuel consumption using the method Vyker suggested. I'll let you know what I get.

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JAZZY... get used to the poor consumption brother, mine WAS so poor it was the main reason I sold it.. Spent a small fortune in trying to sort it but a £55 tank would only give me 200miles, wouldn't make a difference whether I was pootling around town or on the motorway.

I have now gone over to the dark side (Audi A4 2.0 sport), my driving style hasn't changed one bit and to a £55 tank I'm now getting 400 miles.. That's what you should get in the Lex.. They are nice cars but AUDI A4 I find is soooooooo much nicer..

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JAZZY... get used to the poor consumption brother, mine WAS so poor it was the main reason I sold it.. Spent a small fortune in trying to sort it but a £55 tank would only give me 200miles, wouldn't make a difference whether I was pootling around town or on the motorway.

I have now gone over to the dark side (Audi A4 2.0 sport), my driving style hasn't changed one bit and to a £55 tank I'm now getting 400 miles.. That's what you should get in the Lex.. They are nice cars but AUDI A4 I find is soooooooo much nicer..

That's an honest answer, which I appreciate. I was up your neck of the woods only yesterday. I drove up on the Tues on a full tank (from fuel light on), and took the car to Bradford, and back. Drove it dry, til the light came on again and managed to get 23mpg, so it seems to be improving...but I hear ya 6OLDE, it is proving to be an expensive hobby!

What is the mpg on your Audi?

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Jazzy,

Do you know the service history of your car, I mean do you has it been serviced regulary and using quality parts, and on time?

It sounds as if the last owner hasn't serviced the car properly, that's why you could have been getting rubbish mpg. At least 23 mpg is an improvement, but like one of my old school teachers used to write in my school reports 'could do better'.

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The service history is very good. All done by reputable Lexus garage in Twickenham, up until I bought the car. All completed as required at all the major milestones, and every 10,000 miles.

I can't see that this is the cause, but then I really don't know what could be.

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I have re-read all the previous posts, you have given the car a service.

Sounds like you need to give the car a few more good long distance drives, like you did the drive to Bradford. Hopefully the mpg will improve even more.

Could end up costing you lots of ££££ in petrol.

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Recently did an ECU reset, then journeyed up to Bradford and around Mancunia- got 23.3 mpg.

For the journey home, filled the tank full again, from the warning light, reset the trip-o-meter and also added some Redex fuel cleaner.

So far, I've achieved 211 miles in just over half a tank, which is a bit of a miracle. I hope it continues like that!

Also, gonna book in with Tony B. from WIM to get a full geo done, cos the car was jumping around the place when travelling at speed on the motorway.

I'll keep ya posted, as my experiences might well serve someone else with similar problems.

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Ok. guys, did my second calculation for economy and this time used the method described by vyker whereby you fill the tank, use some and then refill the tank, thus working out litres used and mileage etc.etc.

Anyway came back lower this time, but still pretty good at 35mpg

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To be honest I think that's going to be a load of crap that you've linked to, it's like the resistor mod that gives you extra power, worthless really.

If things like that worked everyone would have them and they'd be plastered all over the internet!

Shame as petrol really is getting to stupid prices now :(

As for MPG, it's really easy, it's miles per gallon, so you divide the miles you've just done, by the number of gallons of petrol you've just used and you get the MPG figure.

Easy way is to work it out by filling the car up to the brim, resetting the odo to 0, and then when you go back to fill up note the milage and then also how many litres you've put in, convert that to gallons (an imperial gallon is 4.54609188 litres) and then you're set :)

For example, you've just done 200 miles to 40 litres of petrol, so you'd do this..

40 / 4.54609188 = 8.7987663

200 / 8.7987663 = 22.730459

Which works out at 22.73MPG :)

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You ever noticed how the fuel needle slowly decreases during the top half, but then suddenly starts rapidly decreasing during the bottom half during fuel consumption?!!

I was thinking, hurrah I've got 200 miles out of half a tank so I'm on track for 400 miles to a full tank- WRONG, WRONG, WRONG, WRONG!!

The needle is now down to just above the last "quarter" (cos it aint a quarter marker) and it is nowhere near the 300 mile mark! 400 miles out of the full tank- as likely as spotting a porky pilot.. quelle bummmer!!

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