Real World Fuel Economy

[Activ8]

So having done 800 miles in the car and a good mixture of driving I feel I can report the following. Bear in mind that I have driven Prius for the last 2 years and could get that up to 72mpg on 50+ mile runs with just a little effort.

So if you drive this car like a regular sports saloon and don't care about fuel economy you will average around 38mpg for a full tank... In fact you would be had pressed to get any worse than 36mpg blasting about everywhere. Now my wife's BMW 3 series automatic diesel gives around the same, It does better on motorways at around mid 40's but worse around town at around 26-29mpg so averages out at just under 40mpg per tank. So you are no worse off than in a BMW 2.0d auto but petrol is cheaper than diesel and the 300h feels so much better to drive.

Now Driving a 50mile trip on mixed A road and Motorway driving and driving sensibly then you see this figure climb easily into the mid to late 40's and sensible in town driving delivers up to 50mpg. In two 12 mile trips last week I saw 48mpg which I would never see in my wife's car on the same trip no matter how hard I tried.

Finally this weekend driving a usual route to Wales a return trip of 180 miles and one that driving to the hybrids strengths including a bit of hyper-miling and a trip that I could easily get 75mpg out of the Prius I got a an average of 59.8 miles per gallon. Now my Prius took until it had a few 000's miles on it before the true economy showed so this makes me quite optimistic about 300h especially as it was cold this weekend (warm vs cold weather had as much as 6mpg difference on the Prius).

However the thing I found strange was that the car never went above 60mpg showing at anytime yet averaged 59.8mpg which I found strange. The prius could never go past 99mpg as this was a software limitation and I am wondering if 60mpg is a software limit on the 300h too!

So I am happy so far as it is doing as well as I expected on the economy front but is so much better than I expected as an overall driving package.

[Rob64]

That's very encouraging. When I did my comparative costings when going through the selection process, I assumed I would realistically get 45 mpg from the IS300h. Looks like I'll save even more than I thought

[Activ8]

That's very encouraging. When I did my comparative costings when going through the selection process, I assumed I would realistically get 45 mpg from the IS300h. Looks like I'll save even more than I thought

Depends upon how you drive Rob... but 45+ would be relatively easy to achieve even with a little spirited driving once the car has loosened up!

[Rob64]

I collect mine on Monday afternoon, and I intend to monitor the fuel consumption from the off using the tank brim to brim method. In a few weeks I should have some results.

[DJP]

I've only 450 on the clock and am driving a bit like a grandma but mine since reset, and since haven't reset can only assume that's from when I left the showroom, is 40.1 mpg. I'm not disappointed as I guess it takes a while to settle down, although I'll admit to not understanding why I'm told it will improve over time.

My journeys so far have been pretty short commuting and Dad's taxi type driving.

Like you Activ8 I'm really enjoying the driving experience, and messing around with dials and connected services etc etc.!

[Activ8]

I've only 450 on the clock and am driving a bit like a grandma but mine since reset, and since haven't reset can only assume that's from when I left the showroom, is 40.1 mpg. I'm not disappointed as I guess it takes a while to settle down, although I'll admit to not understanding why I'm told it will improve over time.

My journeys so far have been pretty short commuting and Dad's taxi type driving.

Like you Activ8 I'm really enjoying the driving experience, and messing around with dials and connected services etc etc.!

On the steering wheel controls you can set the trip to show MPG from Reset or from Start of journey or from last fill-up. The default is since last reset so this will be since you picked the car up unless you reset it.

I am not sure why they get more efficient... it may just be that things loosen up but after a few thousanf miles you do see the figures go up by a few MPG. You can also learn to drive the hybid by looking how it is storing energy... The trick with the prius was to accelerate quicky up to speed and then back off the gas completely so that the EV light comes on then catch up the speed on the throttle position in EV to maintain the speed. Likewise ensuring your Battery has good charge by going a little quicker on an A road before you start a hilly climb gives much better Battery assistance and greater fuel economy. You can then recharge the Battery on the decent by gently braking all the way down the hill to increase charge... If there is someone behind you and you don't want to dazzle them with constant brake lights you can drop down a gear on the paddles and it has the same braking effect (on the prius you have a B position on the gear lever for just this reason on the 300h the paddles do just fine).

It can actually be quite fun challenging yourself on a route you do often to see just how much better MPG you can get. The MPG unlike most cars is very dependant on how you drive it.

[Ian J. Parsley]

Must say I've never been below 42mpg or so no matter what I've done!

Driving it hard I sometimes drift below 50mpg, but I'm usually above. A weekly mixed 60 mile round trip unfailingly returns 55mpg.

I got 64.5 from Newtownabbey to Carnlough - so above 60 does appear!

[Activ8]

Must say I've never been below 42mpg or so no matter what I've done!

Driving it hard I sometimes drift below 50mpg, but I'm usually above. A weekly mixed 60 mile round trip unfailingly returns 55mpg.

I got 64.5 from Newtownabbey to Carnlough - so above 60 does appear!

The above 60mpg is good to know... That gives me something to aim for...

[Ian J. Parsley]

You may be able to glance at it on the map, but a lot of it was with the cruise on steadily at 40mph or 50mph. On the way back, for some reason, I got rather less (I think actually there was less traffic so I was doing 60mph in parts), so the round trip was completed at 61mpg.

[michaelH]

Welshpool to Aberystwyth via Machynlleth, then Aberystwyth to Leicester via Llangurig, M54, M6 and M69. 224.5 miles at 63.7 mpg on the display. The later journey was taken carefully because my wife travels badly, but the boot was fully loaded. I suspect that the real figure is nearer to 60 mpg, but after one month my petrol consumption seems to be about half that of my old IS250 auto.

[DJP]

It does seem to be the case that the hybrid uses about half the petrol of the IS250. The actual mpg varying from individual to individual, but anyone wanting to get a feel for the economy can use that fact as a yardstick.

Sent from my Iphone using Lexus OC

[Keith26]

Over1200 miles I've averaged 43mpg. No long open distances hopefully that will be next month so it'll be interesting to see the outcome. 60mpg will appear as will 99.9mpg - leaving the petrol station in eco mode!

[michaelH]

Having managed an astonishing 63.7 over 224 often-hilly miles by driving very carefully and in eco mode (see previous post) I later had the chance to do the same journey at a more normal speed (because this time my wife was medicated and asleep) and I still managed to get a reading of exactly 60.0 (fully laden) for the 165 miles from Humberstone to Aberystwyth. That dropped to 58 after pootling about in Wales for 20 miles or so, and then on the way home (with no passengers) I decided to do the journey as quickly as I (safely and legally!) could, using normal and sport modes. That left me with a reading of 56.2 over the combined total of 351 miles, which suggests about 53 or 54 mpg for the faster return journey, whereas my old IS250 would typically have given me a reading of about 36 (which in reality meant about 34 mpg) when driven in the same way. So there is a real difference in mpg even on a fast open road. Moreover, the IS250's mpg would always drop like a stone once I started driving it on short trips around Leicester, but in the IS300h it holds up really well, as one would expect.

I am guessing that I will find the real consumption figure to be about 2 or 3 mpg less than the readout. But if that means I'm getting about 50 mpg without really trying, then I would be very happy with that. And very happy with the car itself. I thought the old 250 rode well, but this is much better, especially on the bends.

[ColinBarber]

Driving style does play a huge part in the mpg achievable but I also feel there may be a noticeable different between cars. Manufacturing tolerances always have produced differences between petrol engines and I guess that is now extended to hybrid Battery capacity etc. etc.

Also we need to be aware of the difference in economy between the trim levels. An F Sport for example gives up 6.6 mpg, over 10%, compared to the SE on the urban cycle.

[Rabbers]

Michael:

Your two posts come gratifyingly close to confirming my own conclusions of 28 June under Tank Range.

My cumulative consumption (real) has now improved to 17.6 km/l (49.7 mpg) (read-out 17.9 km/l=50.6 mpg)

after 21,500km, and this puts me within tantalisingly easy reach of precisely doubling the 8.9 km/l (25.1 mpg)

I got after 235,000km in two 250s of which I otherwise retain fond memories. In other words, ".... 50 mpg

[17.7 km/l] without really trying...." is proving to be not only a reasonable objective but also a personally

satisfying one.

[Silver Arrow]

There is now no question that if you have to buy a Lexus, then a Hybrid it is!!

[michaelH]

The biggest cost isn't petrol or road tax, but depreciation. Having said that, I suspect that the hybrids tend to hold their value better as well. But for pure driving enjoyment (out of town) there must still be a case for choosing an equivalent 250 with a six speed auto box. Which makes me wonder why this isn't called the IS mark 3 forum. Surely some of us drive the new 250?

[Paul Dresser]

Hi,

I took delivery of my 300H last week, 1st march and on a 17 reg. Absolutely love the car after coming from a BMW 5 series.

I have only had one decent run to Liverpool which was about 48mpg. Since then it has been short trips, about 3.5 miles to work on back, or a run into Leeds, about 6 miles. On these shorter trips, I am averaging about 37mpg. I am being very careful in ECO mode and using all the suggested tips (coasting, anticipation etc).

I guess the thing that will be influencing this is the temperature, about 5c, the fact I am making short trips and the car only just gets up to temp by the time I pull into the yard, I have seat heater on and ventilation set at 23c to warm the car up.

Could the fact that the car is new also play a part, do the engines loosen up?

I was feeling a bit disappointed with the MPG but hoping it will get better.

Any viewpoints on this.

Cheers

 

[Richard1200]

I am on my second IS300h, had this one since May 2105. Never reset the fuel trip and now coming up to 10,000 miles in mostly town or short journeys mine is averaging 47.3mpg. No motorways, no long journeys. Forget all the talk of 50+ that's one off journeys or a short periods of time..

[rayaans]

3 hours ago, Paul Dresser said:

Hi,

I took delivery of my 300H last week, 1st march and on a 17 reg. Absolutely love the car after coming from a BMW 5 series.

I have only had one decent run to Liverpool which was about 48mpg. Since then it has been short trips, about 3.5 miles to work on back, or a run into Leeds, about 6 miles. On these shorter trips, I am averaging about 37mpg. I am being very careful in ECO mode and using all the suggested tips (coasting, anticipation etc).

I guess the thing that will be influencing this is the temperature, about 5c, the fact I am making short trips and the car only just gets up to temp by the time I pull into the yard, I have seat heater on and ventilation set at 23c to warm the car up.

Could the fact that the car is new also play a part, do the engines loosen up?

I was feeling a bit disappointed with the MPG but hoping it will get better.

Any viewpoints on this.

Cheers

 

Short trips are awful for MPG. My wife's car sits at about 30-35mpg most of the time unless going more than 10 miles. 

The reason for this is that the engine doesn't warm up fully for a longer percentage of time on a short journey than a longer one and therefore it keeps the engine on to warm it up. 

MPG should get slightly better over time yes, by 1-3 MPG as the car loosens up and comes out of run in period.

ECO mode doesn't do much for economy and in some instances makes it worse

Try to keep momentum everywhere, slowing down means you need to accelerate again and that uses more fuel. 

I see you're also in Yorkshire - frankly its the worse place to live in terms of MPG - too many hills around!

[Tel]

My 2017 is definitely so much smoother & appears to engage the Battery mode more readily in heavy traffic.

I only drive in Sport Mode & in my previous car averaged c. 48 mpg with 52 mpg on long Motorway high speed runs--perfect.

in the Jura Mountains, close to Switzerland with 4 adults in the car, I got 25mpg going up to the Top & 58mpg returning to the Valley floor.

Cannot wait to see if the new car is marginally better.

Tel

[Steve44]

6 hours ago, Tel said:

My 2017 is definitely so much smoother & appears to engage the battery mode more readily in heavy traffic.

I only drive in Sport Mode & in my previous car averaged c. 48 mpg with 52 mpg on long Motorway high speed runs--perfect.

in the Jura Mountains, close to Switzerland with 4 adults in the car, I got 25mpg going up to the Top & 58mpg returning to the Valley floor.

Cannot wait to see if the new car is marginally better.

Tel

This bodes very well. I pick mine up on the 25th and can't wait.

That's a cracking mpg, driving in sport mode all the time, I can't get near that with mine currently.

[matt8]

I did 100 mile motorway, a portion of if average 50 mph zones. Stayed within speed limits. Averaged 42mpg over the journey, driving in Eco or Regular (never sport). I feel something is wrong, everyone is seeing much better than I am! An Is 300h, 2013 F Sport.

[Steve44]

Hybrid driving style makes a big difference. You need to accelerate up to speed briskly and then lift off and reapply throttle. As does speed and hills!

The early cars seem worse at getting into the Hybrid efficient super cruise mode compared to later mid cycle facelift cars, something was upgraded in the power train as the co2 dropped and mpg increased slightly across the board I think.

My 2014 FSport is the same, averaging around early 40's. When you think about it to get that from a relatively heavy luxury 2.5l petrol auto is impressive regardless.

[Zotto]

To spare some fuel, it may be useful to not use the adaptive cruise control with intense traffic, because the car accelerates too much to reach the set speed (even if I find ACC very comfortable).  Another trick is keep air conditioning on only when necessary; in GS when in ECO mode AC works only for occupied seats, I don't know if it is the same for IS too.