Mpg

[Deadloak]

Those Dunlop tyres are now the factory fitted tyres for the IS instead of the Bridgestones.

Mine is a month old, on Bridgestone's. So they may have been running down the old stock, when mine was build and booted.

David

[crispian]

Not sure how I managed this lol, a mixture of motorway and A road driving.

[rayaans]

YAY!!! my wife beat the 30mpg wall! 32mpg atm!!

Its basically doing 55-60mpg down the hill and when it goes back up its doing some ridiculously low figure so average works out 32mpg! It shows 410miles on a tank cruising range which rapidly drops when going up hills!

[DJP]

YAY!!! my wife beat the 30mpg wall! 32mpg atm!!

Its basically doing 55-60mpg down the hill and when it goes back up its doing some ridiculously low figure so average works out 32mpg! It shows 410miles on a tank cruising range which rapidly drops when going up hills!

I can relate to that! 65 mpg on the way to work - all down big hills. 25 mpg on the way back.

Sent from my iPad using Lexus OC

[darrude]

long commute to work 65miles (20miles A roads), no traffic I get low 50's, hit a bit of traffic and I get high 50's. I drive a little faster than you as well. If I really try (no traffic) setting the needle at 70 and 50 through the road works, then I can get over 60mpg.

[rayaans]

10 mile round trip on sunday - 37mpg - achieved without any sort of hybrid driving technique. My wife was driving. TBH I have noticed that she had a heavy foot on take off from traffic lights which is probably whats killing the MPG

[L3xu5gt]

IS250 F Sport mpg

Motorway journey A1 & M11 managed to get a constant 40 on the bar chart read out, however it only goes upto 40!!!

My overall was 46.8 ...... Not bad for a 250?

[michaelH]

That's very good going from a petrol v6. I once managed to get a reading of 43 mpg in one of the old-model IS250s on a return journey from Leicester to Bexhill on sea, but the reading proved optimistic and no doubt yours will be too. Probably by about 4 mpg? If you were really getting that mpg you should be refuelling after just over 600 miles (assuming a 60 litre/13 gallon refuel and about 6 litres in reserve). That is not too hard to achieve in a 300h, but I doubt if anyone has ever done it in a 250.

[michaelH]

I think I just missed out on the last bar here, but it is almost a full house. I had been stuck in a line of traffic following a pair of HGVs. Real edge of the seat stuff - not.

[Dixgas]

IS250 F Sport mpg

Motorway journey A1 & M11 managed to get a constant 40 on the bar chart read out, however it only goes upto 40!!!

My ooverall was 46.8 ...... Not bad for a 250?

Hi Gary, good to hear from another 250 owner I thought I was the only one. Lexus must have tweaked the V6 in the 3gen., I do a regular run to my daughters ( 230 round trip 50/50 m/way A road ) in the 2gen I was lucky to get 32mpg, driving the same route in the same manner I have had 41mpg and I do have a rather heavy foot, your 46 is very impressive.

D

[rayaans]

IS250 F Sport mpg

Motorway journey A1 & M11 managed to get a constant 40 on the bar chart read out, however it only goes upto 40!!!

My ooverall was 46.8 ...... Not bad for a 250?

Hi Gary, good to hear from another 250 owner I thought I was the only one. Lexus must have tweaked the V6 in the 3gen., I do a regular run to my daughters ( 230 round trip 50/50 m/way A road ) in the 2gen I was lucky to get 32mpg, driving the same route in the same manner I have had 41mpg and I do have a rather heavy foot, your 46 is very impressive.

D

Id be more worried about the reading being wrong or some sort of manipulation of figures as its nigh on impossible to get 46mpg in an IS250. Maybe 38mpg on the motorway in an F-Sport with wider tyres but youd need to be very light footed and possibly travelling at 50mph.

Im calling bull**** on this one

[Dixgas]

IS250 F Sport mpg

Motorway journey A1 & M11 managed to get a constant 40 on the bar chart read out, however it only goes upto 40!!!

My ooverall was 46.8 ...... Not bad for a 250?

Hi Gary, good to hear from another 250 owner I thought I was the only one. Lexus must have tweaked the V6 in the 3gen., I do a regular run to my daughters ( 230 round trip 50/50 m/way A road ) in the 2gen I was lucky to get 32mpg, driving the same route in the same manner I have had 41mpg and I do have a rather heavy foot, your 46 is very impressive.

D

Id be more worried about the reading being wrong or some sort of manipulation of figures as its nigh on impossible to get 46mpg in an IS250. Maybe 38mpg on the motorway in an F-Sport with wider tyres but youd need to be very light footed and possibly travelling at 50mph.

Im calling bull**** on this one

Rayaans

I'm not saying it's a accurate reading, I'm simply pointing out the difference between the two figures, having said that I kept a record of two years miles/fuel on a spreadsheet and found only 4ths difference to what the computer stated, that was on a 2gen IS, I would assume a similar accuracy on this 3gen.

I get about 20mpg town driving.

bull**** was a bit unnecessary.

D

[rayaans]

Rayaans

I'm not saying it's a accurate reading, I'm simply pointing out the difference between the two figures, having said that I kept a record of two years miles/fuel on a spreadsheet and found only 4ths difference to what the computer stated, that was on a 2gen IS, I would assume a similar accuracy on this 3gen.

I get about 20mpg town driving.

bull**** was a bit unnecessary.

D

I meant the original post buddy.

46.8 mpg is theoretically and practically impossible for an IS250 no matter how you drive it.

The only real plausible theory is that the MPG was reset while going down a hill. If I do that in my RX I can achieve 99mpg btw ;)

[L3xu5gt]

The reading of 46.8 was at the end of a 133 mile journey from London, late at night with little traffic using cruise control. You can see from the bar chart that it has consistently registered 40 mpg.

[rayaans]

The reading of 46.8 was at the end of a 133 mile journey from London, late at night with little traffic using cruise control. You can see from the bar chart that it has consistently registered 40 mpg.

Its very odd, something isnt right. The MAX ive achieved in an IS250 is 34mpg but 46.8mpg is way too high. Id say its not registering correctly as a V6 will guzzle through fuel no matter what. I barely get 46mpg in the IS300h!

[ColinBarber]

You can achieve over 40 mpg in a LS400 V8

[wh05apk]

Rayaans, I think you need to learn some economy driving techniques, I had a loan is250 for a couple of days, and achieved about 38 mpg, despite driving into London, my 30th averages about 47 mpg but can achieve 60 mpg quite easily on 20-30 mile runs.

Just because you cannot achieve good figures does not mean others can't, although I must admit 46mpg from an is250 is exceptional, and I doubt if it can be easily repeated.

[L3xu5gt]

Wh05apk, I could not agree more......my previous IS250 3rd generation delivered good fuel return daily, I used to travel a 100 mile round trip on the a17, flat straight roads were a bonus, and as for tyre wear..... I changed my back tyres at 41,000.

[rayaans]

I still dont believe the computer...... 46mpg is way too high and never have I driven an IS250/GS250 which has got anywhere near that!

[ganzoom]

Don't forget hills make a massive difference to mpg. On a flat bit of road with rolling traffic at 50-60mph I've seen 70mpg from our IS300H. Throw in some half decent hills and you can nearly halve that. The energy recovery from going down a hill via the hybrid drive is only about 1/3 efficient, so if your living in a hilly area your mpg will be worse regardless of how you drive.

[michaelH]

I've said it before, but in my experience the gauges always overstate mpg and overstate mph, so "I often get 50 mpg cruising at 70 mph" probably means "I often get 46 mpg cruising at 65 mph". But in contrast I have found the average speed reading to be pretty well spot on over a three hour journey.

But there have been a few occasions with each of my four Lexus cars when for some reason the mpg was exceptional even over longish distances. I don't think any of those occasions can be explained by aid from strong tailwinds, although my fastest and easiest 100+ mile trip on a pedal cycle (many years ago) certainly was. It was exhilarating!

[daylight1]

My own experience tallies with your observations Michael.

My speedo is over-stating by around 4 mph - or else the half a dozen or so speed reporting cameras I pass through regularly are all calibrated 4mph too slow!

The real mpg (tank full to tank empty) is about 10% lower than the average mpg stated on the cars display. I've also noticed there is a variance of up to 10mpg between winter and summer, which is no great surprise given the heavier demand from lights, heating etc.

I've covered almost 25,000 miles, around 75% of which is my 40 mile daily cross town commute, so mostly 30 and 40mph speed limits, and the rest is A road and motorway driving. This is my first hybrid so I needed to learn the driving style to get best fuel economy. When I first got the car I tried all three modes from full tank to empty and the results were:

Sport - 45mpg

Normal - 50mpg

Eco - 53 mpg

I then tried just Eco for a full year and have managed to get 45mpg during the winter and 54mpg during the summer. I've no idea how people are managing to get 60mph plus as an average but I consider what I'm getting as pretty good. Its twice the fuel efficiency I was getting with my previous IS250 V6 so I can't complain and when I consider the road tax is £10 instead of £240 I like it even more.

Overriding all of this though is the benefit of having such a comfortable, quiet and smooth car. I really do find it very relaxing, even when proceeding "briskly" shall we say when the need arises! :D

Robert

[darrude]

Hi has anyone verified the MPG gauge in their IS. I plan on doing the following.

Use phone / sat nav to verify trip computer distance against distance travelled.

verify miles traveled from a full tank to calculate actual mpg.

hopefully will be able to test accuracy of trip computer average mpg gauge....

I did something similar on my Mazda, and it was more or less spot on. Did the same on one of the pool cars at work when driving from Cheshire to the south coast, that car stated over 60mpg, my figures gave it low 50's (that was TDI skoda octavia).

[wh05apk]

That's unusual for a vw group car to exaggerate fuel consumption/emissions, I wonder if that is a common issue!☺

[ColinBarber]

Hi has anyone verified the MPG gauge in their IS.

It's about 4% optimistic, around 2 mpg over although it does seem to vary between tanks. All my previous Lexus vehicles have been the same.